Chassis Codes (C-Codes): Full List
Chassis codes start with C and come from the ABS, traction and stability control, steering and suspension systems. They often switch on the ABS, traction or stability warning light rather than the check engine light. The most common trigger is a wheel speed sensor or its wiring, but because these systems affect braking and steering, repairs belong in a shop.
37Codes
3.1Average severity
16%High or critical
14%DIY-friendly
Severity distribution
Most viewed
All codes (37)
C0020
Chassis
The ABS module saw a fault in the electric pump motor that builds brake pressure during ABS…
Moderate
C0021
Chassis
The brake module thinks the power brake booster isn't giving the assist it should. Check pedal…
High
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
C0561
Chassis
GM's brake or chassis module switched off stability/traction control because of a fault…
Low
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
C1201
Toyota · Chassis
The engine computer reported a fault, so the ABS/VSC unit switched stability and traction…
Low
C121C
Jeep · Chassis
The ESC module asked the engine to cut power and the PCM refused, so stability and traction…
Low
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
C1241
Toyota · Chassis
The ABS/stability control computer saw its supply voltage drop too low, so it shut the systems…
Low
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