U1021
Lost Communication With Anti-Lock Brake System Control Module
U1021 is an OBD-II diagnostic trouble code meaning: Lost Communication With Anti-Lock Brake System Control Module. Common causes: open or short circuit in the communication circuit, abs module malfunction. Estimated repair cost: $56–278.
Symptoms
- The ABS indicator on the dashboard is on
- Disabling the stabilization system (ESP)
- Lack of response to the brake pedal in emergency situations
- Errors in other ABS-related systems
Causes
- Open or short circuit in the communication circuit
- ABS module malfunction
- Poor contact in connectors
- ABS module power problems
- Software error in ABS module
How to Fix
- Check the condition of the ABS module fuses
- Inspect the ABS module connectors and wiring harness
- Check the power and ground of the ABS module
- Scan the ABS module for errors
- If necessary, replace the ABS module
Related codes
FAQ
What does the U1021 code mean?
U1021 is an OBD-II diagnostic trouble code that indicates: Lost Communication With Anti-Lock Brake System Control Module
What causes a U1021 error code?
The most common causes of U1021 include: Open or short circuit in the communication circuit; ABS module malfunction; Poor contact in connectors; ABS module power problems.
How do I fix a U1021 diagnostic trouble code?
To fix U1021: Check the condition of the ABS module fuses. Inspect the ABS module connectors and wiring harness. Check the power and ground of the ABS module. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with U1021?
Limited driving only, diagnose soon
How much does it cost to fix U1021?
The estimated repair cost for U1021 is $56–278. Actual cost depends on your vehicle, location, and labor rates.
See also: Russian version · NationStat