Network
generic or reserved
U356E
Anode Drain Valve Heater Relay Control Circuit
Generic electrical fault on the heater relay for the anode drain valve. The heater prevents drain water from freezing in cold weather.
SystemNetwork
Typegeneric or reserved
GroupU3
Range / number5 / 6E
Possible causes
- Heater relay failed 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: shop recommended
- Estimated cost: 100–600 €
- Estimated time: 0.5–2 h
- Component: anode drain heater relay
- Component: relay wiring
- MIL / check engine light
Sources
References
sae:J2012