Lost Communication with ABS Control Module
Network · CAN Bus
The main control network has lost communication with the ABS/ESC module. This disables all wheel speed-dependent safety systems including ABS, traction control, and electronic stability control.
- Failed ABS/ESC moduleMost common
- CAN bus wiring faultCommon
- Blown ABS module fuseCommon
- Corroded ABS module connectorCommon
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Frequently asked questions about U0121
What does U0121 mean?
The main control network has lost communication with the ABS/ESC module. This disables all wheel speed-dependent safety systems including ABS, traction control, and electronic stability control.
Is U0121 serious?
Fix soon — ABS, traction control, and stability control may be disabled.
How much does it cost to fix U0121?
Repair costs for U0121 range from $300 – $900 depending on the root cause and your vehicle.
Can I drive with U0121?
You can drive short distances but should have it repaired within 1–2 weeks to prevent further damage.