Fault Code 1233
Fault code 12333/2-way valve
Diagnostic conditions
- Ignition on
- Internal auxiliary heater control unit function test
Possible cause of fault
- Electrical fault in electric circuit (plug contact problem)
- Short circuit to ground
- Short circuit to B+
- Open circuit in wiring
- Auxiliary heater control unit faulty
Affected pins
Plug A for auxiliary heater control unit
- Pin 4 '3/2-way valve output'
Plug on 3/2-way valve
- Pin 1 '3/2-way valve input'
- Pin 2 'terminal 31'
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.
