Fault code lookup

ChassisC0040

Caution

Severity: Caution - get it checked when you can

Right Front Wheel Speed Sensor Circuit

26 brands affected · Generic SAE J2012 description.

Key terms: ABS: anti-lock braking, which stops the wheels locking · Stability control: helps stop the car skidding · Tone wheel: a toothed ring read by the wheel speed sensor · Wheel speed sensor: measures how fast each wheel turns · SAE J2012: the standard generic code list

1What it means in plain English

The right front wheel speed sensor signal is missing or unreliable. ABS and stability control may stop working.

2Common causes

  1. Faulty wheel speed sensor
  2. Damaged sensor ring or tone wheel
  3. Damaged wiring or connector
  4. Metal debris on the sensor tip
  5. Wheel bearing damage

3Can I drive?

Caution · drive with care

Normal braking still works, but ABS and stability control may not. Drive carefully, especially in wet or slippery 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 26

BrandCodeDescriptionSystem
Ashok Leyland CVC0040Right Front Wheel Speed Sensor Circuit SAEChassis
BAIC MotorC0040Brake Pedal Switch A BrandChassis
BYDC0040Brake Pedal Switch A BrandChassis
CheryC0040Brake Pedal Switch A BrandChassis
DaewooC0040Brake Pedal Switch A BrandChassis
DFFSC0040Brake Pedal Switch A BrandChassis
DFFXC0040Brake Pedal Switch A BrandChassis
DFXKC0040Brake Pedal Switch A BrandChassis
EOBDC0040Suis pedal brek A BrandChassis
GeelyC0040Brake Pedal Switch A BrandChassis
GMC0040Right Front Wheel Speed Sensor Circuit BrandChassis
Great WallC0040Brake Pedal Switch A BrandChassis
HafeiC0040Brake Pedal Switch A BrandChassis
HoldenC0040Brake Pedal Switch BrandChassis
HondaC0040Right Front Wheel Speed Sensor Circuit SAEChassis
HyundaiC0040Right Front Wheel Speed Sensor Circuit SAEChassis
IsuzuC0040Right Front Wheel Speed Sensor Circuit SAEChassis
Land RoverC0040Brake pedal switch A BrandChassis
MaseratiC0040Brake Pedal Switch Signal Compare Failure BrandChassis
OpelC0040Right Front Wheel Speed Sensor Circuit BrandChassis
PeugeotC0040Right Front Wheel Speed Sensor Circuit SAEChassis
ProtonC0040Right Front Wheel Speed Sensor Circuit SAEChassis
SaabC0040Right Front Wheel Speed Sensor Circuit BrandChassis
MG (SAIC)C0040Brake Switch Fault BrandChassis
TataC0040Right Front Wheel Speed Sensor Circuit SAEChassis
ToyotaC0040Brake pedal sensor fault BrandChassis

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 15

These 7-character codes are manufacturer-specific variants of C0040 and may be reported by some scan tools.

BrandCodeDescriptionSystem
SsangYongC004000Front right wheel speed sensor circuit error BrandChassis
MahindraC004002Brake Light Switch Failure BrandChassis
Mercedes-BenzC004012Brake Light Switch line break BrandChassis
MahindraC004012BLA active; Feedback is not active BrandChassis
MahindraC004014BLA not active; Feedback is active BrandChassis
Mercedes-BenzC00401CBrake light switch supply error - circuit voltage out of range BrandChassis
Mercedes-BenzC00402Abrakelightswitch permanent high with silamemory BrandChassis
Mercedes-BenzC004062BLS Plausibility Failure - signal compare failure BrandChassis
Mercedes-BenzC004084Brake Light Switch line break BrandChassis
Mercedes-BenzC004086No description available Chassis
SmartC004086No description available Chassis
Mercedes-BenzC004087No description available Chassis
SmartC004087No description available Chassis
Mercedes-BenzC0040FABls_pls_plaus_error - 0xFA BrandChassis
Mercedes-BenzC0040FFBls is permanent high (for HHC only) BrandChassis

6Related codes

Browse Cxxx codes or C004xx codes.

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