U0306
Software Incompatibility with Fuel Injector Control Module
The injector driver module identifies itself with a software version that does not match what the engine ECU expects. Engine may not start or runs roughly until both modules are reflashed to compatible versions.
- 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.
- Software flash incomplete or wrong fileCommon
- Gateway module routing CAN messages incorrectlyLess likely
- CAN terminating resistor (120 Ω) drifted out of specLess likely
Parts involved
- Injector Driver Module
- ECM
U0306 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.