Car Diagnostic Codes List and Meaning

Last Updated on April 17, 2025

If you own a car, knowing how to read car diagnostic codes can save you time, money, and unnecessary trips to the mechanic. These codes help you understand what’s wrong with your vehicle before attempting a repair or seeking professional help.

What Are Diagnostic Trouble Codes (DTCs)?

Diagnostic Trouble Codes (DTCs)—also called fault or error codes—are stored by your car’s onboard diagnostic (OBD) system when it detects an issue. These codes are generated when a sensor reports data outside the expected range. While DTCs don’t tell you the exact faulty part, they do guide technicians (or DIYers) to the general problem area.

How to Check and Use DTCs Effectively

When checking DTCs, don’t rely on the code alone. Always refer to the vehicle’s service manual and other technical resources. This helps you avoid unnecessary repairs and potential safety risks. To read the codes, use a reliable OBD2 code reader—either handheld or app-based—compatible with your car.

Complete Car Diagnostic Codes List (OBD-II Overview)

DTCs are categorized into families and typically follow a structure like P0301, where each character has meaning:

• P = Powertrain
• B = Body
• C = Chassis
• U = Network (communication-related)

The second character in the code is usually:

• 0 = Generic (universal across all manufacturers)
• 1 = Manufacturer-specific

The final three digits pinpoint the specific issue. Here’s a general breakdown of what each number range represents:

Code Range	System Function
0, 1, 2	Air/fuel mixture issues
3	Ignition system problems
4	Emission control faults
5	Engine idle control
6	ECU and onboard computer faults
7, 8, 9	Transmission issues
A, B, C	Hybrid propulsion system

Generic vs Manufacturer-Specific Codes

Understanding the difference between generic and manufacturer-specific codes is crucial:

• Generic codes (P0xxx) follow the standardized OBD-II protocol and apply to all car brands.
• Manufacturer-specific codes (P1xxx) are defined by each automaker to cover issues not included in the generic code set.

Additional code groups exist to expand diagnostic capabilities:

• P0xxx, P2xxx, P34xx–P39xx = Generic codes
• P1xxx, P30xx–P33xx = Manufacturer-specific codes

Mastering how to read and interpret car diagnostic trouble codes is essential for effective car maintenance. Whether you’re a DIY car owner or an aspiring mechanic, knowing the difference between generic and manufacturer-specific DTCs—and how to read them—can save you time, money, and headaches on the road.

Here is the powertrain codes list with its full meaning:

P0000 -No DTCs Detected!

P0001 -Problem with the fuel volume regulator control circuit

P0002 -Fuel Volume Regulator Control Circuit Malfunction

P0003 -Low Voltage at Fuel Volume Regulator Control Circuit

P0004 -High Voltage at Fuel Volume Regulator Control Circuit

P0007 -High Voltage at Fuel Shutoff Valve “A” Control Circuit

P0008 -Mechanical timing of the engine malfunction

P0009 -Engine Position System Performance Down

P0010 -Problem With the “A” Camshaft Position Actuator Circuit

P0011 -“A” Camshaft Position – Timing Over-Advanced

P0012 -Bank 1 Intake Camshaft Position Timing- Over-Retarded

P0013 -Exhaust camshaft actuator circuit valve is open/short circuit

P0014 -Exhaust Camshaft Timing Malfunction (Over-Advanced Bank 1)

P0015 -“B” Camshaft Position – Timing Over-Retarded

P0016 -The crankshaft Position and Camshaft Position doesn’t match (Bank 1, Sensor A)

P0017 -Camshaft Position Correlation (Bank 1, Sensor B)

P0018 -The crankshaft Position doesn’t correlate with the Camshaft Position

P0019 -Crankshaft Position – Camshaft Position Correlation Bank 2 Sensor ‘B

P0020 -Intake “A” Camshaft Position Actuator Circuit Malfunction

P0021 -The intake camshaft (Bank 2) position is more advanced

P0022 -Camshaft variable timing solenoid (Bank 2) Issue

P0023 -“B” Camshaft Position Circuit Issue

P0024 -Bank 2 exhaust camshaft is not correct

P0025 -“B” Camshaft position not correct

P0026 -Intake Valve Control Solenoid Circuit Range/Performance (Bank 1)

P0028 -Intake valve control solenoid malfunction

P0030 -HO2S heater control circuit malfunction

P0031 -Low Voltage at HO2S Heater Control Circuit (Bank 1 Sensor 1)

P0035 -High signal at Turbocharger or Supercharger Bypass Valve “A” Control Circuit

P0036 -HO2S control circuit (bank 1, sensor 2) Malfunction

P0037 -Low H02S2 Heater Control Circuit (Bank 1, Sensor 2)

P0042 -Problem with the HO2S Heater Control Circuit (Bank 1 Sensor 3)

P0043 -Low voltage in HO2S Heater Control Circuit (Bank 1 Sensor 3)

P0045 -Turbo/Supercharger Boost Control Solenoid Circuit/Open

P0046 -Issue With the boost control solenoid

P0051 -Low voltage at HO2S Heater Control Circuit (Bank 2 Sensor 1)

P0052 -High Voltage at HO2S Heater Circuit (Bank 2, Sensor 1)

P0053 -HO2S Resistance (Bank 1, Sensor 1)

P0054 -Heated Oxygen Sensor (HO2S)Malfunction

P0087 -Low Pressure at Fuel Rail/System

P0088 -High Pressure at Fuel Rail/System

P0089 -Problem With Fuel Pressure Regulator 1

P0090 -Fuel Pressure Regulator 1 Control Circuit Malfunction

P0091 -Low Voltage at Fuel Pressure Regulator 1 Control Circuit

P0092 -High Voltage at Fuel Pressure Regulator 1 Control Circuit

P0093 -Large Leakage in the Fuel System

P0094 -Small Leakage in the Fuel System

P0095 -Intake Air Temperature Sensor 2 Circuit Malfunction

P0096 -Intake Air Temperature Sensor 2 Circuit Range/Performance Not Matched

P0097 -No Voltage at Intake Air Temperature Sensor 2 Circuit

P0098 -High Voltage at Intake Air Temperature Sensor 2 Circuit (Bank 1)

P0099 -Intake Air Temperature Sensor 2 Circuit Malfunction

P0100 -Faulty MAF Sensor or Circuit

P0101 -Incorrect MAF Circuit Range

P0102 -Low Input at MAF Circuit

P0103 -High Voltage Output at Mass Air Flow Circuit

P0104 -Mass or Volume Air Flow ” A” Circuit Malfunction

P0105 -Barometric Pressure/Manifold Absolute Pressure Circuit Malfunction

P0106 -MAP/Barometric Pressure Circuit Range Mismatch

P0107 -Low Voltage Output at MAP/Barometric Pressure Circuit

P0108 -High Voltage Output at Manifold Absolute Pressure/Barometric Pressure Circuit

P0109 -MAP/BARO Circuit Intermittent

P0110 -Problem in Intake Air Temperature Sensor 1 Circuit Bank 1

P0111 -Intake Air Temperature Sensor 1 Circuit Range/Performance

P0112 -Low Voltage Output at Intake Air Temperature Sensor 1 Circuit

P0113 -High Voltage Output at Intake Air Temperature Sensor 1 Circuit

P0114 -IAT Sensor 1 Bank 1 Circuit Intermittent

P0115 -Engine Coolant Temperature Circuit Malfunction

P0116 -Engine Coolant Temperature Circuit Range Incorrect

P0117 -Low Voltage Output at Engine Coolant Temperature Circuit

P0118 -High Voltage Output at Engine Coolant Temperature Circuit

P0119 -ECT Circuit Intermittent

P0120 -Issue With the Throttle/Pedal Position Sensor/Switch “A” Circuit

P0121 -Throttle/Pedal Position Sensor/Switch “A” Circuit Shows Incorrect Data

P0122 -Low Voltage Output at Throttle/Pedal Position Sensor/Switch “A” Circuit

P0123 -High Voltage Output at Throttle/Pedal Position Sensor/Switch “A” Circuit

P0124 -Throttle/Pedal Position Sensor/Switch “A” Circuit Malfunction

P0125 -Insufficient Coolant Temperature for Closed Loop Fuel Control

P0126 -Insufficient Coolant Temperature for Stable Operation

P0127 -IAT Too High

P0128 -Issue with the Coolant Thermostat

P0129 -Low Output at Barometric Pressure

P0130 -O2 Sensor Circuit Malfunction

P0131 -Low Voltage Output at O2 Sensor Circuit

P0132 -High Voltage Output at O2 Sensor Circuit

P0133 -O2 Sensor Circuit Slow Response

P0134 -O2 Sensor Circuit Totally Stops Working

P0135 -O2 Sensor Heater Circuit Malfunction

P0136 -Downstream O2 Sensor Circuit Malfunction (Bank 1)

P0137 -Low Voltage Output at O2 Sensor Circuit Bank 1 Sensor 2

P0138 -High Voltage Voltage O2 Sensor Circuit

P0139 -O2 Sensor Circuit Bank 1 Sensor 2 Slow Response

P0140 -No Activity Detected at O2 Sensor Circuit Bank 1 Sensor 2

P0141 -Faulty O2 Sensor Heater Circuit (Bank 1, Sensor 2)

P0142 -O2 Sensor Circuit Malfunction (Bank 1, Sensor 3)

P0143 -Low Voltage Output at O2 Sensor Circuit (Bank 1, Sensor 3)

P0144 -High Voltage Output at O2 Sensor Circuit (Bank 1, Sensor 3)

P0145 -O2 Sensor Circuit (Bank 1, Sensor 3) Voltage Drops

P0146 -O2 Sensor Circuit (Bank 1, Sensor 3) Not Responding

P0147 -Faulty O2 Sensor Heater Circuit (Bank 1, Sensor 3)

P0148 -Fuel Delivery Error

P0149 -Fuel Timing Error (Fuel Pressure Malfunction)

P0150 -Faulty O2 Sensor Circuit (Bank 2, Sensor 1)

P0151 -Low Voltage Output at O2 Sensor Circuit (Bank 2, Sensor 1)

P0152 -High Voltage Output at O2 Sensor Circuit (Bank 2, Sensor 1)

P0153 -O2 Sensor Circuit (Bank 2, Sensor 1) Slow Response

P0154 -O2 Sensor Circuit (Bank 2, Sensor 1) Not Responding

P0155 -O2 Sensor Heater Circuit (Bank 2, Sensor 1) Malfunction

P0156 -Faulty O2 Sensor Circuit (Bank 2 Sensor 2)

P0157 -Low Voltage Output at O2 Sensor Circuit (Bank 2 Sensor 2)

P0158 -High Voltage Output O2 Sensor Circuit (Bank 2 Sensor 2)

P0159 -O2 Sensor Circuit (Bank 2 Sensor 2) Slow Response

P0160 -O2 Sensor Circuit (Bank 2 Sensor 2) Not Responding

P0161 -O2 Sensor Heater Circuit (Bank 2 Sensor 2) Malfunction

P0162 -Faulty O2 Sensor Circuit (Bank 2 Sensor 3)

P0163 -Low Voltage Output at O2 Sensor Circuit (Bank 2 Sensor 3)

P0164 -High Voltage Output at O2 Sensor Circuit (Bank 2 Sensor 3)

P0165 -O2 Sensor Circuit (Bank 2 Sensor 3) Slow Response

P0166 -O2 Sensor Circuit (Bank 2 Sensor 3) Not Responding

P0167 -Problem with the O2 Sensor Heater Circuit (Bank 2 Sensor 3)

P0168 -High Fuel Temperature

P0169 -Too Much Fuel Composition

P0170 -Fuel Trim Crossed Its Limit (Bank 1)

P0171 -Fuel System Too Lean

P0172 -Fuel System Too Rich

P0173 -Air-Fuel Ratio is Too Low or High

P0174 -Fuel System Too Lean (Bank 2)

P0175 -Fuel System Too Rich (Bank 2)

P0176 -Fuel Composition Sensor Circuit Malfunction

P0177 -Fuel Composition Sensor Circuit Range Mismatch

P0178 -Low Output at Fuel Composition Sensor Circuit

P0179 -High Output at Fuel Composition Sensor Circuit

P0180 -Issue with the Fuel Temperature Sensor A Circuit

P0341 -Camshaft Position Sensor “A” Circuit Malfunction

P0504 -Brake Switch “A”/”B” Correlation

P000A -Slow Response at Intake ” A” Camshaft Position (Bank 1)

P000B -Faulty position and timing of the camshaft

Chassis codes

C0xxx – Generic
C1xxx – Manufacturer-specific
C2xxx – Manufacturer-specific
C3xxx – Generic

Here is the chassis codes list with its full meaning:

C0035 – Left Front Wheel Speed Sensor Malfunction

C0040 – Right Front Wheel Speed Sensor Malfunction

C0045 – Faulty Left Rear Wheel Speed Circuit

C0050 – Right Rear Wheel Speed Sensor Malfunction

C0161 – Faulty ABS Brake Circuit

C0226 – Left Front Speed Sensor Malfunction

C0237 – Rear Speed Sensor Malfunction

C0245 – Faulty Electronic Brake Control Module (EBCM)

C0265 – Bad connection at the EBCM ground

C0267 – An open or shorted pump motor

C0281 – Brake Switch Circuit malfunction

C0300 – Rear Propshaft Speed Sensor Malfunction

C0327 – Transfer Case Encoder Malfunction

C0550 – ABS/traction control module malfunction

C0710 – Faulty Steering Wheel Angle Sensor

C0800 – Control module power circuit -Low input

C1214 – Right front abs inlet coil valve failure

C1222 – Wheel speed mismatch after driving

C1223 – Faulty brake lamp

C1225 – Wheel speed sensor malfunctioning

C1226 – Lamp Brake Warning Output Circuit Short To Ground

C1232 – Faulty Left Front Wheel Speed Sensor Assembly

C1233 – Right Front Wheel Speed Circuit Open Or Shorted

C1234 – Faulty Right Front Wheel Speed Sensor

Body codes

B0xxx – Generic
B1xxx – Manufacturer-specific
B2xxx – Manufacturer-specific
B3xxx – Generic

B0001 -Drivers frontal stage 1 deployment control malfunction

B0002 -Drivers frontal stage 2 deployment control malfunction

B0003 -Problem With Driver Frontal Stage 3 Deployment Control

B0004 -Driver Knee Bolster Deployment Control Malfunction

B0005 -Steering column sensor Malfunction

B0010 -Issue in the Passenger Frontal Stage 1 Deployment Control

B0011 -Passenger Frontal stage 2 Deployment Control Malfunction

B0012 -Passenger Frontal stage 3 Deployment Control Malfunction

B0013 -Steering Wheel Inflator Module Malfunction

B0020 -Faulty Left Side Airbag Deployment Control

B0021 -Passenger Seat Side Air Bag Not Working Properly

B0022 -Low Resistance- Passenger Seat Belt Retractor Pretensioner Deployment Loop

B0028 -Faulty Right Side Airbag Deployment Control

B0029 -Right Front/Passenger Side Air Bag Module Malfunction

B0030 -Issue With the Second Row Left Side Airbag

Network communication codes

U0xxx – Generic
U1xxx – Manufacturer-specific
U2xxx – Manufacturer-specific
U3xxx – Generic
Let’s decode the codes with details.

U0001 -High-Speed CAN communication bus

U0002 -Faulty Control Module (Area Network (CAN)

U0073 -Control Module Communication Bus “A” Off

U0100 -Lost Communication with ECM/PCM ‘A

U0101 -Lost Communication with TCM

U0107 -Lost Communication with Throttle Actuator (TAC) Module

U0109 -Fuel Pump Control Module harness is open or shorted

U010C -Lost Communication With Turbocharger/Supercharger Control Module

U0121 -Lost Communication With ABS Module

U0126 -Lost Communication with Steering Angle Sensor (SAS) Module

U0140 -Lost Communication With Body Control Module

U0141 -Lost Communication With Body Control Module “A”

U0151 -Faulty Restraints Control Module (RCM)

U0155 -Open circuit in the CAN bus positive circuit

U0164 -Issue with Heating, Ventilation, and Air Conditioning (HVAC) Control Module

U0184 -Lost Communication with Radio

U0300 -Internal Control Module Software Incompatibility

U0401 -Invalid Data Received from ECM/PCM

U0402 -Transmission Control Module Shows Invalid Data

U0415 -Invalid Data Received From ABS

U0422 -Fault in the Body Control Module (BCM)

U0428 -Invalid Data Received From Steering Angle Sensor Module

U3000 -General Memory Failure in Control Module

U3003 -Over amperage condition for the battery state

These are some of the normal car diagnostic codes that you are likely to find on most vehicles. There are more than 5,000 codes that are commonly used. OBD codes were standardized using SAE J2012 and ISO 15031-6 standards. All you have to do is to search for software and download all the 5000 plus codes.