U0318
Software Incompatibility with Power Steering Control Module
A control module has detected that its software version does not match the electric power steering module. Steering may stay functional but become heavy if the EPS goes into a fallback mode.
- Check engine light: Yes
- 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.
- EPS software/calibration mismatchCommon
- Used EPS module fitted from different vehiclePossible
- Gateway module routing CAN messages incorrectlyLess likely
Parts involved
- Power Steering Module
- Control Module
U0318 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.