U0145
Lost Communication with Restraints Control Module Auxiliary
A secondary or auxiliary airbag/restraints controller (e.g. for rear or curtain bags) has stopped responding. The airbag warning lamp lights up and parts of the restraint system may be disabled.
- Check engine light: Not always
- Emissions related: No
- Repair difficulty: hard
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
Common causes
Ordered by how often each turns out to be the cause.
- Auxiliary restraint module failedPossible
- Gateway module routing CAN messages incorrectlyLess likely
- CAN terminating resistor (120 Ω) drifted out of specLess likely
Parts involved
- Auxiliary Restraint Module
- CAN Bus Wiring
U0145 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.