Network
generic / SAE
U01B9
Lost Communication With Switch Input Module C
ECU lost communication with switch input module C (collects switch signals — windows, lights, etc.).
SystemNetwork
Typegeneric / SAE
GroupU0
Range / number1 / B9
Possible causes
- Module unpowered 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: 80–600 €
- Estimated time: 0.5–3 h
- Component: switch input module c
- Component: can bus
- MIL / check engine light
Sources
References
sae:J2012