OBD-II Trouble Codes: Meaning & Fixes
OBD-II trouble codes are five-character codes stored by your vehicle's computers when a monitored system goes out of range. Browse them by system (P, B, C, U), by sub-system or by the symptom you notice. Each code page explains what the code means, how serious it is, whether you can keep driving, the likely causes in order, how to diagnose it and what repairs typically cost.
648Codes
2.8Average severity
16%High or critical
18%DIY-friendly
Severity distribution
Most viewed
B0001
Body
The airbag module found a fault in the firing circuit for the driver's front airbag (stage 1).
High
P0135
Powertrain
The heater inside the upstream oxygen sensor on bank 1 isn't working or its circuit is faulty.
Low
P0174
Powertrain
The cylinder bank without cylinder 1 is running lean even with the maximum fuel correction…
Moderate
P0300
Powertrain
The engine computer sees misfires that jump between cylinders or hit several cylinders at once.
High
P0420
Powertrain
The bank 1 catalytic converter no longer stores enough oxygen to clean the exhaust properly.
Low
P0430
Powertrain
The bank 2 converter on a V6, V8 or split-exhaust engine isn't cleaning the exhaust well enough.
Low
All codes (410)
C0035
Chassis
The ABS module lost a valid signal from the driver-side front wheel speed sensor.
Moderate
C0040
Chassis
The ABS module isn't getting a usable signal from the passenger-side front wheel speed sensor.
Moderate
C0045
Chassis
The ABS module lost a valid signal from the driver-side rear wheel speed sensor.
Moderate
C0050
Chassis
The ABS module can't trust the passenger-side rear wheel speed signal and has shut ABS off.
Moderate
C0055
Chassis
The ABS module lost the combined rear-axle speed signal used on many GM trucks, vans and SUVs.
Moderate
C0110
Chassis
The GM brake module (EBCM) found a fault in the ABS pump motor circuit and switched ABS off.
Moderate
C0121
Chassis
The GM brake module can't confirm power to the ABS solenoid valves through its valve relay.
Moderate
C0131
Chassis
The GM brake module sees an implausible or out-of-range signal from the brake pressure sensor.
Moderate
C0161
Chassis
The GM brake module gets a brake-light switch signal that doesn't make sense. Check your brake…
Moderate
C0265
Chevrolet · Chassis
The ABS module on many GM trucks found its built-in relay isn't delivering power, so ABS shuts…
Moderate
C0545
Chevrolet · Chassis
The electric power steering module can't trust its torque sensor, so steering assist may cut…
High
C0550
Chassis
A GM chassis module, most often the brake module (EBCM), failed its own internal self-check.
Moderate
C1130
Nissan · Chassis
The ABS/VDC unit isn't getting a valid engine signal from the ECM, so it switches stability…
Moderate
C1145
Ford · Chassis
Ford's ABS module found an open or short in the right front (passenger-side) wheel speed sensor…
Moderate
C1155
Ford · Chassis
Ford's ABS module saw the left front (driver-side) sensor circuit go open or shorted, often…
Moderate
C1165
Ford · Chassis
Ford's ABS module detected an open or short in the right rear wheel speed sensor wiring…
Moderate
C1175
Ford · Chassis
Electrical fault in the left rear sensor circuit, or in the single rear-axle sensor on some…
Moderate
C1185
Ford · Chassis
The ABS module's internal power relay isn't delivering voltage to the valves and pump, so ABS…
Moderate
C1223
Toyota · Chassis
The stability control side of the system has been told that ABS has a fault, so VSC and TRAC…
Moderate
C1233
Ford · Chassis
The left front sensor wiring checks out, but no speed pulses reached the ABS module while…
Moderate
C1234
Ford · Chassis
While driving, the right front speed signal dropped out or disagreed with the other wheels.
Moderate
C1252
Toyota · Chassis
The brake pressure pump ran far longer than normal without reaching or holding its target…
High
C1253
Toyota · Chassis
The brake ECU sees a pump motor relay or its monitor line not doing what it was told to do.
Moderate
C1256
Toyota · Chassis
The brake system's high-pressure accumulator is below its minimum, so power brake assist can't…
Critical
C1300
Toyota · Chassis
The ABS/VSC computer failed its own internal self-test and has shut down ABS and stability…
Moderate
C1391
Toyota · Chassis
The hybrid brake system is losing stored hydraulic pressure internally, so the pump keeps…
High
C1513
Kia · Chassis
The stability control module thinks the brake light switch is lying about whether you're…
Moderate
C1611
Hyundai · Chassis
The ABS/ESC module stopped hearing from the engine computer on the CAN bus and shut off…
Moderate
C2200
Jeep · Chassis
The ABS module found a fault in its own electronics and shut off ABS, traction and stability…
Moderate
C2217
Jeep · Chassis
The electric power steering module found a fault inside itself and may reduce or cut steering…
High