C0056 code meaning
Left Rear Wheel Speed Sensor Circuit Intermittent
What C0056 means
Covers an intermittent fault in the left rear wheel speed sensor circuit, where the signal is lost or corrupted only part of the time rather than permanently. The ABS/ESC module expects a clean pulse train proportional to wheel speed; a chafed wire that opens over bumps, a loose or corroded connector, a cracked sensor or a contaminated encoder ring can make the signal drop out briefly. Because the fault is sporadic it may set and self-clear, and ABS, traction and stability control drop out only during the glitches. The ABS warning lamp is set and base braking remains. Bosch active wheel speed sensors depend on a stable two-wire supply and a clean air gap to the encoder. No code-specific public bulletin was confirmed; the entry follows the SAE J2012 generic definition.
C0056 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of C0056
- Intermittent ABS warning lamp
- ABS/ESC drops out briefly
- Speedometer flickers
Common causes of C0056
- Most likelyChafed wire or loose connector
- PossibleCracked sensor or contaminated encoder
- Less likelyExcessive or varying air gap
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Wheel speed sensor rlSensor wiring
What each part of C0056 means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 56 | The exact fault in that area. |
What to do next
- Note C0056 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about C0056
What does C0056 mean?
C0056 means "Left Rear Wheel Speed Sensor Circuit Intermittent". Covers an intermittent fault in the left rear wheel speed sensor circuit, where the signal is lost or corrupted only part of the time rather than permanently. It is a generic code, so it means the same on every make.
Is it safe to drive with C0056?
Drive gently and only to a workshop. With C0056 the car can go into limp mode (reduced power) to protect itself.
Will C0056 fail an emissions test?
C0056 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is C0056 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will C0056 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.