ChassisC1021
CautionSeverity: Caution - get it checked when you can
ECU internal fault (temperature sensor system)
Key terms: ABS: anti-lock braking, which stops the wheels locking · Stability control: helps stop the car skidding · Wheel speed sensor: measures how fast each wheel turns
1What it means in plain English
A chassis system has a fault, usually ABS, traction control or stability control, but some makes use this range for airbags, electric power steering or park brakes.
2Common causes
- Faulty wheel speed sensor
- Damaged sensor ring or wiring
- Faulty ABS module
- Low brake fluid
- Wheel bearing damage
3Can I drive?
If the code names an airbag or SRS system, the airbag may not deploy in a crash: have it diagnosed promptly. If it names electric power steering, the assist may fail and the steering can become heavy: stop safely if that happens. If it names the brakes or park brake, have it checked before driving when braking feels abnormal. Otherwise ABS and stability control may be disabled: drive carefully, especially in wet conditions, and have it checked soon.
This page gives general information. It is not professional advice. For a definite diagnosis and a repair quote, ask a qualified mechanic to inspect the car.
4Brand data 23
| Brand | Code | Description | System |
|---|---|---|---|
| BAIC Motor | C1021 | Front left wheel speed = 0kph Brand | Chassis |
| Mercedes-Benz | C1021 | No description available | Chassis |
| BMW | C1021 | diaphragm travel sensor: short circuit to voltage supply Brand | Chassis |
| Daewoo | C1021 | Front Right Wheel Speed Sensor Short Circuit or Circuit Open Brand | Chassis |
| DFFS | C1021 | Temperature sensor fault Brand | Chassis |
| Geely | C1021 | Front left wheel speed = 0km/h Brand | Chassis |
| GM | C1021 | No description available | Chassis |
| Holden | C1021 | No description available | Chassis |
| Honda | C1021 | No description available | Chassis |
| Isuzu | C1021 | No description available | Chassis |
| Land Rover | C1021 | ABS Booster Control Pressure Brand | Chassis |
| Mahindra | C1021 | EPS Internal Fault& EPS exits Steering mode Brand | Chassis |
| Maserati | C1021 | No description available | Chassis |
| Opel | C1021 | No description available | Chassis |
| Peugeot | C1021 | No description available | Chassis |
| Proton | C1021 | No description available | Chassis |
| Saab | C1021 | No description available | Chassis |
| MG (SAIC) | C1021 | Failsafe Relay Open Brand | Chassis |
| Smart | C1021 | No description available | Chassis |
| Sprinter | C1021 | No description available | Chassis |
| Suzuki | C1021 | Right-Front Wheel Speed Sensor Circuit Voltage Brand | Chassis |
| Tata | C1021 | No description available | Chassis |
| Toyota | C1021 | ECU internal fault (temperature sensor system) Brand | Chassis |
Legend: SAE is the generic J2012 description; Brand is text taken from that manufacturer’s data. Manufacturer rows keep the wording and language of the source data, and non-English text is tagged so screen readers pronounce it correctly.
5Extended variant codes 4
These 7-character codes are manufacturer-specific variants of C1021 and may be reported by some scan tools.
| Brand | Code | Description | System |
|---|---|---|---|
| Mercedes-Benz | C102100 | No description available | Chassis |
| SsangYong | C102100 | Faulty EPB ECU (power control circuit board watchdog function) Brand | Chassis |
| SsangYong | C102101 | Wheel speed sensor front-RH open/short Brand | Chassis |
| Mercedes-Benz | C102148 | SW supervision Brand | Chassis |
6Related codes
Browse Cxxx codes or C102xx codes.