Network
generic or reserved
U300F
Ignition Input Accessory
Fault on the ignition ACC (accessory) input. A communication loss with this module breaks any function relying on its data — diagnostic tools may show 'no response' and dependent modules can fall into limp mode.
SystemNetwork
Typegeneric or reserved
GroupU3
Range / number– / 0F
Possible causes
- Ignition switch contacts worn high
- Gateway module routing CAN messages incorrectly low
- CAN terminating resistor (120 Ω) drifted out of spec low
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
Inspection / repair
- Difficulty: medium
- DIY: possible
- Estimated cost: 40–400 €
- Estimated time: 0.5–2 h
- Component: ignition input
- Component: wiring
- MIL / check engine light
Sources
References
sae:J2012