Network
generic / SAE
U0121
Lost Communication with ABS Control Module
The CAN messages from the ABS module are missing. ABS, ESP/ESC and traction control all become inactive (warning lamps illuminate), the speedometer may go to zero on cars that derive vehicle speed from the ABS module, and adaptive cruise control is disabled.
SystemNetwork
Typegeneric / SAE
GroupU0
Range / number1 / 21
Possible causes
- ABS module unpowered (often a corroded ground or fuse) high
- CAN wiring to ABS broken medium
- ABS module failed medium
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 80–1800 €
- Estimated time: 1–6 h
- Component: abs control module
- Component: can bus wiring
- MIL / check engine light
Sources
References
sae:J2012