Fault Code 0664

Fault code 0664

Fuel level display

Diagnostic conditions
- Ignition on
- Fuel supply warning light on
- Internal auxiliary heater control unit function test

Possible cause of fault
- Fuel quantity in vehicle tank on Reserve (< 12 liters)
- Open circuit in CAN Infotainment (no signal/communication)
- Auxiliary heater control unit faulty

Affected pins
Plug A for auxiliary heater control unit
- Pin 2 'CAN Infotainment (high)'
- Pin 3 'CAN Infotainment (low)'

Diagnosis/troubleshooting

NOTE:
Visual inspection: During the next check, first ensure that the affected pins of the 14-pin plug connection on the wiring harness are neither damaged nor corroded. Remove any soiling or corrosion/oxidation. Replace damaged parts/wires.