OBD-II PIDs

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OBD-II PIDs (On-board diagnostics Parameter IDs) are codes used to request data from a vehicle, used as a diagnostic tool.

SAE standard J/1979 defines many PIDs, but manufacturers also define many more PIDs specific to their vehicles. All light duty vehicles (i.e. less than 8,500 pounds) sold in North America since 1996, as well as medium duty vehicles (i.e. 8,500-14,000 pounds) beginning in 2005, and heavy duty vehicles (i.e. greater than 14,000 pounds) beginning in 2010,[citation needed] are required to support OBD-II diagnostics, using a standardized data link connector, and a subset of the SAE J/1979 defined PIDs (or SAE J/1939 as applicable for medium/heavy duty vehicles), primarily for state mandated emissions inspections.

Typically, an automotive technician will use PIDs with a scan tool connected to the vehicle's OBD-II connector.

  • The technician enters the PID
  • The scan tool sends it to the vehicle's controller–area network (CAN)-bus, VPW, PWM, ISO, KWP. (After 2008, CAN only)
  • A device on the bus recognizes the PID as one it is responsible for, and reports the value for that PID to the bus
  • The scan tool reads the response, and displays it to the technician

Modes[edit]

There are ten modes of operation described in the latest OBD-II standard SAE J1979. They are as follows:

Mode (hex) Description
01 Show current data
02 Show freeze frame data
03 Show stored Diagnostic Trouble Codes
04 Clear Diagnostic Trouble Codes and stored values
05 Test results, oxygen sensor monitoring (non CAN only)
06 Test results, other component/system monitoring (Test results, oxygen sensor monitoring for CAN only)
07 Show pending Diagnostic Trouble Codes (detected during current or last driving cycle)
08 Control operation of on-board component/system
09 Request vehicle information
0A Permanent Diagnostic Trouble Codes (DTCs) (Cleared DTCs)

Vehicle manufacturers are not required to support all modes. Each manufacturer may define additional modes above #9 (e.g.: mode 22 as defined by SAE J2190 for Ford/GM, mode 21 for Toyota) for other information e.g. the voltage of the traction battery in a hybrid electric vehicle (HEV).[1]

Standard PIDs[edit]

The table below shows the standard OBD-II PIDs as defined by SAE J1979. The expected response for each PID is given, along with information on how to translate the response into meaningful data. Again, not all vehicles will support all PIDs and there can be manufacturer-defined custom PIDs that are not defined in the OBD-II standard.

Note that modes 1 and 2 are basically identical, except that Mode 1 provides current information, whereas Mode 2 provides a snapshot of the same data taken at the point when the last diagnostic trouble code was set. The exceptions are PID 01, which is only available in Mode 1, and PID 02, which is only available in Mode 2. If Mode 2 PID 02 returns zero, then there is no snapshot and all other Mode 2 data is meaningless.

When using Bit-Encoded-Notation, quantities like C4 means bit 4 from data byte C. Each bit is numerated from 0 to 7, so 7 is the most significant bit and 0 is the least significant bit.

A B C D
A7 A6 A5 A4 A3 A2 A1 A0 B7 B6 B5 B4 B3 B2 B1 B0 C7 C6 C5 C4 C3 C2 C1 C0 D7 D6 D5 D4 D3 D2 D1 D0

Mode 01[edit]

PID
(hex)
Data bytes returned Description Min value Max value Units Formula[a]
00 4 PIDs supported [01 - 20] Bit encoded [A7..D0] == [PID $01..PID $20] See below
01 4 Monitor status since DTCs cleared. (Includes malfunction indicator lamp (MIL) status and number of DTCs.) Bit encoded. See below
02 2 Freeze DTC
03 2 Fuel system status Bit encoded. See below
04 1 Calculated engine load value 0 100  % A*100/255
05 1 Engine coolant temperature -40 215 °C A-40
06 1 Short term fuel % trim—Bank 1 -100 Subtracting Fuel (Rich Condition) 99.22 Adding Fuel (Lean Condition)  % (A-128) * 100/128
07 1 Long term fuel % trim—Bank 1 -100 Subtracting Fuel (Rich Condition) 99.22 Adding Fuel (Lean Condition)  % (A-128) * 100/128
08 1 Short term fuel % trim—Bank 2 -100 Subtracting Fuel (Rich Condition) 99.22 Adding Fuel (Lean Condition)  % (A-128) * 100/128
09 1 Long term fuel % trim—Bank 2 -100 Subtracting Fuel (Rich Condition) 99.22 Adding Fuel (Lean Condition)  % (A-128) * 100/128
0A 1 Fuel pressure 0 765 kPa (gauge) A*3
0B 1 Intake manifold absolute pressure 0 255 kPa (absolute) A
0C 2 Engine RPM 0 16,383.75 rpm ((A*256)+B)/4
0D 1 Vehicle speed 0 255 km/h A
0E 1 Timing advance -64 63.5 ° relative to #1 cylinder (A-128)/2
0F 1 Intake air temperature -40 215 °C A-40
10 2 MAF air flow rate 0 655.35 grams/sec ((A*256)+B) / 100
11 1 Throttle position 0 100  % A*100/255
12 1 Commanded secondary air status Bit encoded. See below
13 1 Oxygen sensors present [A0..A3] == Bank 1, Sensors 1-4. [A4..A7] == Bank 2...
14 2 Bank 1, Sensor 1:
Oxygen sensor voltage,
Short term fuel trim

0
-100(lean)

1.275
99.2(rich)
Volts
%
A/200
(B-128) * 100/128 (if B==$FF, sensor is not used in trim calc)
15 2 Bank 1, Sensor 2:
Oxygen sensor voltage,
Short term fuel trim

0
-100(lean)

1.275
99.2(rich)
Volts
%
A/200
(B-128) * 100/128 (if B==$FF, sensor is not used in trim calc)
16 2 Bank 1, Sensor 3:
Oxygen sensor voltage,
Short term fuel trim

0
-100(lean)

1.275
99.2(rich)
Volts
%
A/200
(B-128) * 100/128 (if B==$FF, sensor is not used in trim calc)
17 2 Bank 1, Sensor 4:
Oxygen sensor voltage,
Short term fuel trim

0
-100(lean)

1.275
99.2(rich)
Volts
%
A/200
(B-128) * 100/128 (if B==$FF, sensor is not used in trim calc)
18 2 Bank 2, Sensor 1:
Oxygen sensor voltage,
Short term fuel trim

0
-100(lean)

1.275
99.2(rich)
Volts
%
A/200
(B-128) * 100/128 (if B==$FF, sensor is not used in trim calc)
19 2 Bank 2, Sensor 2:
Oxygen sensor voltage,
Short term fuel trim

0
-100(lean)

1.275
99.2(rich)
Volts
%
A/200
(B-128) * 100/128 (if B==$FF, sensor is not used in trim calc)
1A 2 Bank 2, Sensor 3:
Oxygen sensor voltage,
Short term fuel trim

0
-100(lean)

1.275
99.2(rich)
Volts
%
A/200
(B-128) * 100/128 (if B==$FF, sensor is not used in trim calc)
1B 2 Bank 2, Sensor 4:
Oxygen sensor voltage,
Short term fuel trim

0
-100(lean)

1.275
99.2(rich)
Volts
%
A/200
(B-128) * 100/128 (if B==$FF, sensor is not used in trim calc)
1C 1 OBD standards this vehicle conforms to Bit encoded. See below
1D 1 Oxygen sensors present Similar to PID 13, but [A0..A7] == [B1S1, B1S2, B2S1, B2S2, B3S1, B3S2, B4S1, B4S2]
1E 1 Auxiliary input status A0 == Power Take Off (PTO) status (1 == active)
[A1..A7] not used
1F 2 Run time since engine start 0 65,535 seconds (A*256)+B
20 4 PIDs supported [21 - 40] Bit encoded [A7..D0] == [PID $21..PID $40] See below
21 2 Distance traveled with malfunction indicator lamp (MIL) on 0 65,535 km (A*256)+B
22 2 Fuel Rail Pressure (relative to manifold vacuum) 0 5177.265 kPa ((A*256)+B) * 0.079
23 2 Fuel Rail Pressure (diesel, or gasoline direct inject) 0 655,350 kPa (gauge) ((A*256)+B) * 10
24 4 O2S1_WR_lambda(1):
Equivalence Ratio
Voltage
0
0
1.999
7.999
N/A
V
((A*256)+B)*2/65535 or ((A*256)+B)/32768
((C*256)+D)*8/65535 or ((C*256)+D)/8192
25 4 O2S2_WR_lambda(1):
Equivalence Ratio
Voltage
0
0
2
8
N/A
V
((A*256)+B)*2/65535
((C*256)+D)*8/65535
26 4 O2S3_WR_lambda(1):
Equivalence Ratio
Voltage
0
0
2
8
N/A
V
((A*256)+B)*2/65535
((C*256)+D)*8/65535
27 4 O2S4_WR_lambda(1):
Equivalence Ratio
Voltage
0
0
2
8
N/A
V
((A*256)+B)*2/65535
((C*256)+D)*8/65535
28 4 O2S5_WR_lambda(1):
Equivalence Ratio
Voltage
0
0
2
8
N/A
V
((A*256)+B)*2/65535
((C*256)+D)*8/65535
29 4 O2S6_WR_lambda(1):
Equivalence Ratio
Voltage
0
0
2
8
N/A
V
((A*256)+B)*2/65535
((C*256)+D)*8/65535
2A 4 O2S7_WR_lambda(1):
Equivalence Ratio
Voltage
0
0
2
8
N/A
V
((A*256)+B)*2/65535
((C*256)+D)*8/65535
2B 4 O2S8_WR_lambda(1):
Equivalence Ratio
Voltage
0
0
2
8
N/A
V
((A*256)+B)*2/65535
((C*256)+D)*8/65535
2C 1 Commanded EGR 0 100  % A*100/255
2D 1 EGR Error -100 99.22  % (A-128) * 100/128
2E 1 Commanded evaporative purge 0 100  % A*100/255
2F 1 Fuel Level Input 0 100  % A*100/255
30 1 # of warm-ups since codes cleared 0 255 N/A A
31 2 Distance traveled since codes cleared 0 65,535 km (A*256)+B
32 2 Evap. System Vapor Pressure -8,192 8,192 Pa ((A*256)+B)/4 (A and B are two's complement signed)
33 1 Barometric pressure 0 255 kPa (Absolute) A
34 4 O2S1_WR_lambda(1):
Equivalence Ratio
Current
0
-128
1.999
127.99
N/A
mA
((A*256)+B)/32,768
((C*256)+D)/256 - 128
35 4 O2S2_WR_lambda(1):
Equivalence Ratio
Current
0
-128
2
128
N/A
mA
((A*256)+B)/32,768
((C*256)+D)/256 - 128
36 4 O2S3_WR_lambda(1):
Equivalence Ratio
Current
0
-128
2
128
N/A
mA
((A*256)+B)/32768
((C*256)+D)/256 - 128
37 4 O2S4_WR_lambda(1):
Equivalence Ratio
Current
0
-128
2
128
N/A
mA
((A*256)+B)/32,768
((C*256)+D)/256 - 128
38 4 O2S5_WR_lambda(1):
Equivalence Ratio
Current
0
-128
2
128
N/A
mA
((A*256)+B)/32,768
((C*256)+D)/256 - 128
39 4 O2S6_WR_lambda(1):
Equivalence Ratio
Current
0
-128
2
128
N/A
mA
((A*256)+B)/32,768
((C*256)+D)/256 - 128
3A 4 O2S7_WR_lambda(1):
Equivalence Ratio
Current
0
-128
2
128
N/A
mA
((A*256)+B)/32,768
((C*256)+D)/256 - 128
3B 4 O2S8_WR_lambda(1):
Equivalence Ratio
Current
0
-128
2
128
N/A
mA
((A*256)+B)/32,768
((C*256)+D)/256 - 128
3C 2 Catalyst Temperature
Bank 1, Sensor 1
-40 6,513.5 °C ((A*256)+B)/10 - 40
3D 2 Catalyst Temperature
Bank 2, Sensor 1
-40 6,513.5 °C ((A*256)+B)/10 - 40
3E 2 Catalyst Temperature
Bank 1, Sensor 2
-40 6,513.5 °C ((A*256)+B)/10 - 40
3F 2 Catalyst Temperature
Bank 2, Sensor 2
-40 6,513.5 °C ((A*256)+B)/10 - 40
40 4 PIDs supported [41 - 60] Bit encoded [A7..D0] == [PID $41..PID $60] See below
41 4 Monitor status this drive cycle Bit encoded. See below
42 2 Control module voltage 0 65.535 V ((A*256)+B)/1000
43 2 Absolute load value 0 25,700  % ((A*256)+B)*100/255
44 2 Command equivalence ratio 0 2 N/A ((A*256)+B)/32768
45 1 Relative throttle position 0 100  % A*100/255
46 1 Ambient air temperature -40 215 °C A-40
47 1 Absolute throttle position B 0 100  % A*100/255
48 1 Absolute throttle position C 0 100  % A*100/255
49 1 Accelerator pedal position D 0 100  % A*100/255
4A 1 Accelerator pedal position E 0 100  % A*100/255
4B 1 Accelerator pedal position F 0 100  % A*100/255
4C 1 Commanded throttle actuator 0 100  % A*100/255
4D 2 Time run with MIL on 0 65,535 minutes (A*256)+B
4E 2 Time since trouble codes cleared 0 65,535 minutes (A*256)+B
4F 4 Maximum value for equivalence ratio, oxygen sensor voltage, oxygen sensor current, and intake manifold absolute pressure 0, 0, 0, 0 255, 255, 255, 2550 , V, mA, kPa A, B, C, D*10
50 4 Maximum value for air flow rate from mass air flow sensor 0 2550 g/s A*10, B, C, and D are reserved for future use
51 1 Fuel Type From fuel type table see below
52 1 Ethanol fuel % 0 100  % A*100/255
53 2 Absolute Evap system Vapor Pressure 0 327.675 kPa ((A*256)+B)/200
54 2 Evap system vapor pressure -32,767 32,768 Pa ((A*256)+B)-32767
55 2 Short term secondary oxygen sensor trim bank 1 and bank 3 -100 99.22  % (A-128)*100/128
(B-128)*100/128
56 2 Long term secondary oxygen sensor trim bank 1 and bank 3 -100 99.22  % (A-128)*100/128
(B-128)*100/128
57 2 Short term secondary oxygen sensor trim bank 2 and bank 4 -100 99.22  % (A-128)*100/128
(B-128)*100/128
58 2 Long term secondary oxygen sensor trim bank 2 and bank 4 -100 99.22  % (A-128)*100/128
(B-128)*100/128
59 2 Fuel rail pressure (absolute) 0 655,350 kPa ((A*256)+B) * 10
5A 1 Relative accelerator pedal position 0 100  % A*100/255
5B 1 Hybrid battery pack remaining life 0 100  % A*100/255
5C 1 Engine oil temperature -40 210 °C A - 40
5D 2 Fuel injection timing -210.00 301.992 ° (((A*256)+B)-26,880)/128
5E 2 Engine fuel rate 0 3212.75 L/h ((A*256)+B)*0.05
5F 1 Emission requirements to which vehicle is designed Bit Encoded
60 4 PIDs supported [61 - 80] Bit encoded [A7..D0] == [PID $61..PID $80] See below
61 1 Driver's demand engine - percent torque -125 125  % A-125
62 1 Actual engine - percent torque -125 125  % A-125
63 2 Engine reference torque 0 65,535 Nm A*256+B
64 5 Engine percent torque data -125 125  % A-125 Idle
B-125 Engine point 1
C-125 Engine point 2
D-125 Engine point 3
E-125 Engine point 4
65 2 Auxiliary input / output supported Bit Encoded
66 5 Mass air flow sensor
67 3 Engine coolant temperature
68 7 Intake air temperature sensor
69 7 Commanded EGR and EGR Error
6A 5 Commanded Diesel intake air flow control and relative intake air flow position
6B 5 Exhaust gas recirculation temperature
6C 5 Commanded throttle actuator control and relative throttle position
6D 6 Fuel pressure control system
6E 5 Injection pressure control system
6F 3 Turbocharger compressor inlet pressure
70 9 Boost pressure control
71 5 Variable Geometry turbo (VGT) control
72 5 Wastegate control
73 5 Exhaust pressure
74 5 Turbocharger RPM
75 7 Turbocharger temperature
76 7 Turbocharger temperature
77 5 Charge air cooler temperature (CACT)
78 9 Exhaust Gas temperature (EGT) Bank 1 Special PID. See below
79 9 Exhaust Gas temperature (EGT) Bank 2 Special PID. See below
7A 7 Diesel particulate filter (DPF)
7B 7 Diesel particulate filter (DPF)
7C 9 Diesel Particulate filter (DPF) temperature
7D 1 NOx NTE control area status
7E 1 PM NTE control area status
7F 13 Engine run time
80 4 PIDs supported [81 - A0] Bit encoded [A7..D0] == [PID $81..PID $A0] See below
81 21 Engine run time for Auxiliary Emissions Control Device(AECD)
82 21 Engine run time for Auxiliary Emissions Control Device(AECD)
83 5 NOx sensor
84 Manifold surface temperature
85 NOx reagent system
86 Particulate matter (PM) sensor
87 Intake manifold absolute pressure
A0 4 PIDs supported [A1 - C0] Bit encoded [A7..D0] == [PID $A1..PID $C0] See below
C0 4 PIDs supported [C1 - E0] Bit encoded [A7..D0] == [PID $C1..PID $E0] See below
C3  ?  ?  ?  ?  ? Returns numerous data, including Drive Condition ID and Engine Speed*
C4  ?  ?  ?  ?  ? B5 is Engine Idle Request
B6 is Engine Stop Request*
PID
(hex)
Data bytes returned Description Min value Max value Units Formula[a]

Mode 02[edit]

Mode 02 accepts the same PIDs as mode 01, with the same meaning, but information given is from when the freeze frame was created.

You have to send the frame number in the data section of the message.

PID
(hex)
Data bytes returned Description Min value Max value Units Formula[a]
02 2 DTC that caused freeze frame to be stored. BCD encoded. Decoded as in mode 3

Mode 03[edit]

PID
(hex)
Data bytes returned Description Min value Max value Units Formula[a]
N/A n*6 Request trouble codes 3 codes per message frame. See below

Mode 04[edit]

PID
(hex)
Data bytes returned Description Min value Max value Units Formula[a]
N/A 0 Clear trouble codes / Malfunction indicator lamp (MIL) / Check engine light Clears all stored trouble codes and turns the MIL off.

Mode 05[edit]

PID
(hex)
Data bytes returned Description Min value Max value Units Formula[a]
0100 OBD Monitor IDs supported ($01 – $20)
0101 O2 Sensor Monitor Bank 1 Sensor 1 0.00 1.275 Volts 0.005 Rich to lean sensor threshold voltage
0102 O2 Sensor Monitor Bank 1 Sensor 2 0.00 1.275 Volts 0.005 Rich to lean sensor threshold voltage
0103 O2 Sensor Monitor Bank 1 Sensor 3 0.00 1.275 Volts 0.005 Rich to lean sensor threshold voltage
0104 O2 Sensor Monitor Bank 1 Sensor 4 0.00 1.275 Volts 0.005 Rich to lean sensor threshold voltage
0105 O2 Sensor Monitor Bank 2 Sensor 1 0.00 1.275 Volts 0.005 Rich to lean sensor threshold voltage
0106 O2 Sensor Monitor Bank 2 Sensor 2 0.00 1.275 Volts 0.005 Rich to lean sensor threshold voltage
0107 O2 Sensor Monitor Bank 2 Sensor 3 0.00 1.275 Volts 0.005 Rich to lean sensor threshold voltage
0108 O2 Sensor Monitor Bank 2 Sensor 4 0.00 1.275 Volts 0.005 Rich to lean sensor threshold voltage
0109 O2 Sensor Monitor Bank 3 Sensor 1 0.00 1.275 Volts 0.005 Rich to lean sensor threshold voltage
010A O2 Sensor Monitor Bank 3 Sensor 2 0.00 1.275 Volts 0.005 Rich to lean sensor threshold voltage
010B O2 Sensor Monitor Bank 3 Sensor 3 0.00 1.275 Volts 0.005 Rich to lean sensor threshold voltage
010C O2 Sensor Monitor Bank 3 Sensor 4 0.00 1.275 Volts 0.005 Rich to lean sensor threshold voltage
010D O2 Sensor Monitor Bank 4 Sensor 1 0.00 1.275 Volts 0.005 Rich to lean sensor threshold voltage
010E O2 Sensor Monitor Bank 4 Sensor 2 0.00 1.275 Volts 0.005 Rich to lean sensor threshold voltage
010F O2 Sensor Monitor Bank 4 Sensor 3 0.00 1.275 Volts 0.005 Rich to lean sensor threshold voltage
0110 O2 Sensor Monitor Bank 4 Sensor 4 0.00 1.275 Volts 0.005 Rich to lean sensor threshold voltage
0201 O2 Sensor Monitor Bank 1 Sensor 1 0.00 1.275 Volts 0.005 Lean to Rich sensor threshold voltage
0202 O2 Sensor Monitor Bank 1 Sensor 2 0.00 1.275 Volts 0.005 Lean to Rich sensor threshold voltage
0203 O2 Sensor Monitor Bank 1 Sensor 3 0.00 1.275 Volts 0.005 Lean to Rich sensor threshold voltage
0204 O2 Sensor Monitor Bank 1 Sensor 4 0.00 1.275 Volts 0.005 Lean to Rich sensor threshold voltage
0205 O2 Sensor Monitor Bank 2 Sensor 1 0.00 1.275 Volts 0.005 Lean to Rich sensor threshold voltage
0206 O2 Sensor Monitor Bank 2 Sensor 2 0.00 1.275 Volts 0.005 Lean to Rich sensor threshold voltage
0207 O2 Sensor Monitor Bank 2 Sensor 3 0.00 1.275 Volts 0.005 Lean to Rich sensor threshold voltage
0208 O2 Sensor Monitor Bank 2 Sensor 4 0.00 1.275 Volts 0.005 Lean to Rich sensor threshold voltage
0209 O2 Sensor Monitor Bank 3 Sensor 1 0.00 1.275 Volts 0.005 Lean to Rich sensor threshold voltage
020A O2 Sensor Monitor Bank 3 Sensor 2 0.00 1.275 Volts 0.005 Lean to Rich sensor threshold voltage
020B O2 Sensor Monitor Bank 3 Sensor 3 0.00 1.275 Volts 0.005 Lean to Rich sensor threshold voltage
020C O2 Sensor Monitor Bank 3 Sensor 4 0.00 1.275 Volts 0.005 Lean to Rich sensor threshold voltage
020D O2 Sensor Monitor Bank 4 Sensor 1 0.00 1.275 Volts 0.005 Lean to Rich sensor threshold voltage
020E O2 Sensor Monitor Bank 4 Sensor 2 0.00 1.275 Volts 0.005 Lean to Rich sensor threshold voltage
020F O2 Sensor Monitor Bank 4 Sensor 3 0.00 1.275 Volts 0.005 Lean to Rich sensor threshold voltage
0210 O2 Sensor Monitor Bank 4 Sensor 4 0.00 1.275 Volts 0.005 Lean to Rich sensor threshold voltage
PID
(hex)
Data bytes returned Description Min value Max value Units Formula[a]

Mode 09[edit]

PID
(hex)
Data bytes returned Description Min value Max value Units Formula[a]
00 4 Mode 9 supported PIDs (01 to 20) Bit encoded. [A7..D0] = [PID $01..PID $20] See below
01 1 VIN Message Count in PID 02. Only for ISO 9141-2, ISO 14230-4 and SAE J1850. Usually value will be 5.
02 17-20 Vehicle Identification Number (VIN) 17-char VIN, ASCII-encoded and left-padded with null chars (0x00) if needed to.
03 1 Calibration ID message count for PID 04. Only for ISO 9141-2, ISO 14230-4 and SAE J1850. It will be a multiple of 4 (4 messages are needed for each ID).
04 16 Calibration ID Up to 16 ASCII chars. Data bytes not used will be reported as null bytes (0x00).
05 1 Calibration verification numbers (CVN) message count for PID 06. Only for ISO 9141-2, ISO 14230-4 and SAE J1850.
06 4 Calibration Verification Numbers (CVN) Raw data left-padded with null characters (0x00). Usually displayed as hex string.
07 1 In-use performance tracking message count for PID 08 and 0B. Only for ISO 9141-2, ISO 14230-4 and SAE J1850. 8 10 8 if sixteen (16) values are required to be reported, 9 if eighteen (18) values are required to be reported, and 10 if twenty (20) values are required to be reported (one message reports two values, each one consisting in two bytes).
08 4 In-use performance tracking for spark ignition vehicles 4 or 5 messages, each one containing 4 bytes (two values). See below
09 1 ECU name message count for PID 0A
0A 20 ECU name ASCII-coded. Right-padded with null chars (0x00).
0B 4 In-use performance tracking for compression ignition vehicles 5 messages, each one containing 4 bytes (two values). See below
PID
(hex)
Data bytes returned Description Min value Max value Units Formula[a]
  1. ^ a b c d e f g h i In the formula column, letters A, B, C, etc. represent the decimal equivalent of the first, second, third, etc. bytes of data. Where a (?) appears, contradictory or incomplete information was available.

Bitwise encoded PIDs[edit]

Some of the PIDs in the above table cannot be explained with a simple formula. A more elaborate explanation of these data is provided here:

Mode 1 PID 00[edit]

A request for this PID returns 4 bytes of data. Each bit, from MSB to LSB, represents one of the next 32 PIDs and is giving information about if it is supported.

For example, if the car response is BE1FA813, it can be decoded like this:

Hexadecimal B E 1 F A 8 1 3
Binary 1 0 1 1 1 1 1 0 0 0 0 1 1 1 1 1 1 0 1 0 1 0 0 0 0 0 0 1 0 0 1 1
Supported? Yes No Yes Yes Yes Yes Yes No No No No Yes Yes Yes Yes Yes Yes No Yes No Yes No No No No No No Yes No No Yes Yes
PID number 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F 20

So, supported PIDs are: 01, 03, 04, 05, 06, 07, 0C, 0D, 0E, 0F, 10, 11, 13, 15, 1C, 1F and 20

Mode 1 PID 01[edit]

A request for this PID returns 4 bytes of data.

The first byte contains two pieces of information. Bit A7 (MSB of byte A, the first byte) indicates whether or not the MIL (check engine light) is illuminated. Bits A6 through A0 represent the number of diagnostic trouble codes currently flagged in the ECU.

The second, third, and fourth bytes give information about the availability and completeness of certain on-board tests. Note that test availability is indicated by set (1) bit and completeness is indicated by reset (0) bit.

Bit Name Definition
A7 MIL Off or On, indicates if the CEL/MIL is on (or should be on)
A6-A0 DTC_CNT Number of confirmed emissions-related DTCs available for display.
B7 RESERVED Reserved (should be 0)
B3 NO NAME 0 = Spark ignition monitors supported
1 = Compression ignition monitors supported

Here are the common bit B definitions, they are test based.

Test available Test incomplete
Misfire B0 B4
Fuel System B1 B5
Components B2 B6

The third and fourth bytes are to be interpreted differently depending on if the engine is spark ignition or compression ignition. In the second (B) byte, bit 3 indicates how to interpret the C and D bytes, with 0 being spark and 1 (set) being compression.

The bytes C and D for spark ignition monitors:

Test available Test incomplete
Catalyst C0 D0
Heated Catalyst C1 D1
Evaporative System C2 D2
Secondary Air System C3 D3
A/C Refrigerant C4 D4
Oxygen Sensor C5 D5
Oxygen Sensor Heater C6 D6
EGR System C7 D7

And the bytes C and D for compression ignition monitors:

Test available Test incomplete
NMHC Catalyst[a] C0 D0
NOx/SCR Monitor C1 D1
Boost Pressure C3 D3
Exhaust Gas Sensor C5 D5
PM filter monitoring C6 D6
EGR and/or VVT System C7 D7
  1. ^ NMHC may stand for Non-Methane HydroCarbons, but J1979 does not enlighten us.

Mode 1 PID 41[edit]

A request for this PID returns 4 bytes of data. The first byte is always zero. The second, third, and fourth bytes give information about the availability and completeness of certain on-board tests. Note that test availability is represented by a set (1) bit and completeness is represented by a reset (0) bit:

Test enabled Test incomplete
Reserved B3 B7
Components B2 B6
Fuel System B1 B5
Misfire B0 B4
EGR System C7 D7
Oxygen Sensor Heater C6 D6
Oxygen Sensor C5 D5
A/C Refrigerant C4 D4
Secondary Air System C3 D3
Evaporative System C2 D2
Heated Catalyst C1 D1
Catalyst C0 D0

Mode 1 PID 78[edit]

A request for this PID will return 9 bytes of data. The first byte is a bit encoded field indicating which EGT sensors are supported:

Byte Description
A Supported EGT sensors
B-C Temperature read by EGT11
D-E Temperature read by EGT12
F-G Temperature read by EGT13
H-I Temperature read by EGT14

The first byte is bit-encoded as follows:

Bit Description
A7-A4 Reserved
A3 EGT bank 1, sensor 4 Supported?
A2 EGT bank 1, sensor 3 Supported?
A1 EGT bank 1, sensor 2 Supported?
A0 EGT bank 1, sensor 1 Supported?

The remaining bytes are 16 bit integers indicating the temperature in degrees Celsius in the range -40 to 6513.5 (scale 0.1), using the usual (A \times 256 + B) / 10 - 40 formula (MSB is A, LSB is B). Only values for which the corresponding sensor is supported are meaningful.

The same structure applies to PID 79, but values are for sensors of bank 2.

Mode 3 (no PID required)[edit]

A request for this mode returns a list of the DTCs that have been set. The list is encapsulated using the ISO 15765-2 protocol.

If there are two or fewer DTCs (4 bytes) they are returned in an ISO-TP Single Frame (SF). Three or more DTCs in the list are reported in multiple frames, with the exact count of frames dependent on the communication type and addressing details.

Each trouble code requires 2 bytes to describe. The text description of a trouble code may be decoded as follows. The first character in the trouble code is determined by the first two bits in the first byte:

A7-A6 First DTC character
00 P - Powertrain
01 C - Chassis
10 B - Body
11 U - Network

The two following digits are encoded as 2 bits. The second character in the DTC is a number defined by the following table:

A5-A4 Second DTC character
00 0
01 1
10 2
11 3

The third character in the DTC is a number defined by

A3-A0 Third DTC character
0000 0
0001 1
0010 2
0011 3
0100 4
0101 5
0110 6
0111 7
1000 8
1001 9
1010 A
1011 B
1100 C
1101 D
1110 E
1111 F

The fourth and fifth characters are defined in the same way as the third, but using bits B7-B4 and B3-B0. The resulting five-character code should look something like "U0158" and can be looked up in a table of OBD-II DTCs. Hexadecimal characters (0-9, A-F), while relatively rare, are allowed in the last 3 positions of the code itself.

Mode 9 PID 08[edit]

It provides information about track in-use performance for catalyst banks, oxygen sensor banks, evaporative leak detection systems, EGR systems and secondary air system.

The numerator for each component or system tracks the number of times that all conditions necessary for a specific monitor to detect a malfunction have been encountered. The denominator for each component or system tracks the number of times that the vehicle has been operated in the specified conditions.

All data items of the In-use Performance Tracking record consist of two (2) bytes and are reported in this order (each message contains two items, hence the message length is 4):

Mnemonic Description
OBDCOND OBD Monitoring Conditions Encountered Counts
IGNCNTR Ignition Counter
CATCOMP1 Catalyst Monitor Completion Counts Bank 1
CATCOND1 Catalyst Monitor Conditions Encountered Counts Bank 1
CATCOMP2 Catalyst Monitor Completion Counts Bank 2
CATCOND2 Catalyst Monitor Conditions Encountered Counts Bank 2
O2SCOMP1 O2 Sensor Monitor Completion Counts Bank 1
O2SCOND1 O2 Sensor Monitor Conditions Encountered Counts Bank 1
O2SCOMP2 O2 Sensor Monitor Completion Counts Bank 2
O2SCOND2 O2 Sensor Monitor Conditions Encountered Counts Bank 2
EGRCOMP EGR Monitor Completion Condition Counts
EGRCOND EGR Monitor Conditions Encountered Counts
AIRCOMP AIR Monitor Completion Condition Counts (Secondary Air)
AIRCOND AIR Monitor Conditions Encountered Counts (Secondary Air)
EVAPCOMP EVAP Monitor Completion Condition Counts
EVAPCOND EVAP Monitor Conditions Encountered Counts
SO2SCOMP1 Secondary O2 Sensor Monitor Completion Counts Bank 1
SO2SCOND1 Secondary O2 Sensor Monitor Conditions Encountered Counts Bank 1
SO2SCOMP2 Secondary O2 Sensor Monitor Completion Counts Bank 2
SO2SCOND2 Secondary O2 Sensor Monitor Conditions Encountered Counts Bank 2

Mode 9 PID 0B[edit]

It provides information about track in-use performance for NMHC catalyst, NOx catalyst monitor, NOx adsorber monitor, PM filter monitor, exhaust gas sensor monitor, EGR/ VVT monitor, boost pressure monitor and fuel system monitor.

All data items consist of two (2) bytes and are reported in this order (each message contains two items, hence message length is 4):

Mnemonic Description
OBDCOND OBD Monitoring Conditions Encountered Counts
IGNCNTR Ignition Counter
HCCATCOMP NMHC Catalyst Monitor Completion Condition Counts
HCCATCOND NMHC Catalyst Monitor Conditions Encountered Counts
NCATCOMP NOx/SCR Catalyst Monitor Completion Condition Counts
NCATCOND NOx/SCR Catalyst Monitor Conditions Encountered Counts
NADSCOMP NOx Adsorber Monitor Completion Condition Counts
NADSCOND NOx Adsorber Monitor Conditions Encountered Counts
PMCOMP PM Filter Monitor Completion Condition Counts
PMCOND PM Filter Monitor Conditions Encountered Counts
EGSCOMP Exhaust Gas Sensor Monitor Completion Condition Counts
EGSCOND Exhaust Gas Sensor Monitor Conditions Encountered Counts
EGRCOMP EGR and/or VVT Monitor Completion Condition Counts
EGRCOND EGR and/or VVT Monitor Conditions Encountered Counts
BPCOMP Boost Pressure Monitor Completion Condition Counts
BPCOND Boost Pressure Monitor Conditions Encountered Counts
FUELCOMP Fuel Monitor Completion Condition Counts
FUELCOND Fuel Monitor Conditions Encountered Counts

Enumerated PIDs[edit]

Some PIDs are to be interpreted specially, and aren't necessarily exactly bitwise encoded, or in any scale. The values for these PIDs are enumerated.

Mode 1 PID 03[edit]

A request for this PID returns 2 bytes of data. The first byte describes fuel system #1.

Value Description
1 Open loop due to insufficient engine temperature
2 Closed loop, using oxygen sensor feedback to determine fuel mix
4 Open loop due to engine load OR fuel cut due to deceleration
8 Open loop due to system failure
16 Closed loop, using at least one oxygen sensor but there is a fault in the feedback system

Any other value is an invalid response. There can only be one bit set at most.

The second byte describes fuel system #2 (if it exists) and is encoded identically to the first byte.

Mode 1 PID 12[edit]

A request for this PID returns a single byte of data which describes the secondary air status.

Value Description
1 Upstream
2 Downstream of catalytic converter
4 From the outside atmosphere or off
8 Pump commanded on for diagnostics

Any other value is an invalid response. There can only be one bit set at most.

Mode 1 PID 1C[edit]

A request for this PID returns a single byte of data which describes which OBD standards this ECU was designed to comply with. The different values the data byte can hold are shown below, next to what they mean:

Value Description
1 OBD-II as defined by the CARB
2 OBD as defined by the EPA
3 OBD and OBD-II
4 OBD-I
5 Not OBD compliant
6 EOBD (Europe)
7 EOBD and OBD-II
8 EOBD and OBD
9 EOBD, OBD and OBD II
10 JOBD (Japan)
11 JOBD and OBD II
12 JOBD and EOBD
13 JOBD, EOBD, and OBD II
14 Reserved
15 Reserved
16 Reserved
17 Engine Manufacturer Diagnostics (EMD)
18 Engine Manufacturer Diagnostics Enhanced (EMD+)
19 Heavy Duty On-Board Diagnostics (Child/Partial) (HD OBD-C)
20 Heavy Duty On-Board Diagnostics (HD OBD)
21 World Wide Harmonized OBD (WWH OBD)
22 Reserved
23 Heavy Duty Euro OBD Stage I without NOx control (HD EOBD-I)
24 Heavy Duty Euro OBD Stage I with NOx control (HD EOBD-I N)
25 Heavy Duty Euro OBD Stage II without NOx control (HD EOBD-II)
26 Heavy Duty Euro OBD Stage II with NOx control (HD EOBD-II N)
27 Reserved
28 Brazil OBD Phase 1 (OBDBr-1)
29 Brazil OBD Phase 2 (OBDBr-2)
30 Korean OBD (KOBD)
31 India OBD I (IOBD I)
32 India OBD II (IOBD II)
33 Heavy Duty Euro OBD Stage VI (HD EOBD-IV)
34-250 Reserved
251-255 Not available for assignment (SAE J1939 special meaning)

Fuel Type Coding[edit]

Mode 1 PID 51 returns a value from an enumerated list giving the fuel type of the vehicle. The fuel type is returned as a single byte, and the value is given by the following table:

Value Description
0 Not available
1 Gasoline
2 Methanol
3 Ethanol
4 Diesel
5 LPG
6 CNG
7 Propane
8 Electric
9 Bifuel running Gasoline
10 Bifuel running Methanol
11 Bifuel running Ethanol
12 Bifuel running LPG
13 Bifuel running CNG
14 Bifuel running Propane
15 Bifuel running Electricity
16 Bifuel running electric and combustion engine
17 Hybrid gasoline
18 Hybrid Ethanol
19 Hybrid Diesel
20 Hybrid Electric
21 Hybrid running electric and combustion engine
22 Hybrid Regenerative
23 Bifuel running diesel

Any other value is reserved by ISO/SAE. There are currently no definitions for flexible-fuel vehicle.

Non-standard PIDs[edit]

The majority of all OBD-II PIDs in use are non-standard. For most modern vehicles, there are many more functions supported on the OBD-II interface than are covered by the standard PIDs, and there is relatively minor overlap between vehicle manufacturers for these non-standard PIDs.

There is very limited information available in the public domain for non-standard PIDs. The primary source of information on non-standard PIDs across different manufacturers is maintained by the US-based Equipment and Tool Institute and only available to members. The price of ETI membership for access to scan codes starts from US$7,500.[2]

However, even ETI membership will not provide full documentation for non-standard PIDs. ETI state:[2]

Some OEMs refuse to use ETI as a one-stop source of scan tool information. They prefer to do business with each tool company separately. These companies also require that you enter into a contract with them. The charges vary but here is a snapshot of today's[when?] per year charges as we know them:
GM $50,000
Honda $5,000
Suzuki $1,000
BMW $17,500 plus $1,000 per update. Updates occur every quarter. (This is more now, but do not have exact number)

CAN (11-bit) Bus format[edit]

The PID query and response occurs on the vehicle's CAN Bus. Standard OBD requests and responses use functional addresses. The diagnostic reader initiates a query using CAN ID $7DF, which acts as a broadcast address, and accepts responses from any ID in the range $7E8 to $7EF. ECUs that can respond to OBD queries listen both to the functional broadcast ID of $7DF and one assigned ID in the range $7E0 to $7E7. Their response has an ID of their assigned ID plus 8 e.g. $7E8 through $7EF.

This approach allows up to eight ECUs, each independently responding to OBD queries. The diagnostic reader can use the ID in the ECU response frame to continue communication with a specific ECU. In particular, multi-frame communication requires a response to the specific ECU ID rather than to ID $7DF.

CAN bus may also be used for communication beyond the standard OBD messages. Physical addressing uses particular CAN IDs for specific modules (e.g., 720 for the instrument cluster in Fords) with proprietary frame payloads.

Query[edit]

The functional PID query is sent to the vehicle on the CAN bus at ID 7DFh, using 8 data bytes. The bytes are:

Byte
PID Type 0 1 2 3 4 5 6 7
SAE Standard Number of
additional
data bytes:
2
Mode
01 = show current data;
02 = freeze frame;
etc.
PID code
(e.g.: 05 = Engine coolant temperature)
not used
(may be 55h)
Vehicle specific Number of
additional
data bytes:
3
Custom mode: (e.g.: 22 = enhanced data) PID code
(e.g.: 4980h)
not used
(may be 00h or 55h)

Response[edit]

The vehicle responds to the PID query on the CAN bus with message IDs that depend on which module responded. Typically the engine or main ECU responds at ID 7E8h. Other modules, like the hybrid controller or battery controller in a Prius, respond at 07E9h, 07EAh, 07EBh, etc. These are 8h higher than the physical address the module responds to. Even though the number of bytes in the returned value is variable, the message uses 8 data bytes regardless (CAN bus protocol form Frameformat with 8 data bytes). The bytes are:

Byte
PID Type 0 1 2 3 4 5 6 7
SAE Standard
7E8h,
7E9h,
7EAh,
etc.
Number of
additional
data bytes:
3 to 6
Custom mode
Same as query, except that 40h is added to the mode value. So:
41h = show current data;
42h = freeze frame;
etc.
PID code
(e.g.: 05 = Engine coolant temperature)
value of the specified parameter, byte 0 value, byte 1 (optional) value, byte 2 (optional) value, byte 3 (optional) not used
(may be 00h or 55h)
Vehicle specific
7E8h, or 8h + physical ID of module.
Number of
additional
data bytes:
4to 7
Custom mode: same as query, except that 40h is added to the mode value.(e.g.: 62h = response to mode 22h request) PID code
(e.g.: 4980h)
value of the specified parameter, byte 0 value, byte 1 (optional) value, byte 2 (optional) value, byte 3 (optional)
Vehicle specific
7E8h, or 8h + physical ID of module.
Number of
additional
data bytes:
3
7Fh this a general response usually indicating the module doesn't recognize the request. Custom mode: (e.g.: 22h = enhanced diagnostic data by PID, 21h = enhanced data by offset) 31h not used
(may be 00h)

See also[edit]

References[edit]

  1. ^ "Escape PHEV TechInfo - PIDs". Electric Auto Association - Plug in Hybrid Electric Vehicle. Retrieved 11 December 2013. 
  2. ^ a b "ETI Full Membership FAQ". Retrieved 29 November 2013.  showing cost of access to OBD-II PID documentation

External links[edit]