Fault Code 1408

Fault code 1408

Undervoltage cutout (internal)

NOTE: The 'internal' threshold can be modified using the 9588 Porsche System Tester II in the 'Coding' menu item under 'Threshold'.

NOTE: Using the 9588 Porsche System Tester II, the menu item 'Coding' under 'Undervoltage cutout' can be switched to the value 'external' (12.2 V).

Diagnostic conditions
- Ignition on
- Internal auxiliary heater control unit function test

Possible cause of fault
- Voltage limit value not reached (< 9.6 V)
- Electrical fault in electric circuit (plug contact problem)
- Open circuit in wiring
- Auxiliary heater control unit faulty

Affected pins
Connector B
- Pin 1 'terminal 30'
- Pin 2 'terminal 31'

Diagnosis/troubleshooting

NOTE:
Visual inspection: In the next troubleshooting section, please check first that the affected fuses are not faulty. Replace faulty fuse(s) and determine and remedy the cause according to troubleshooting instructions. The affected pins on the auxiliary heater control unit plug connection must be neither damaged nor corroded. The wiring of the affected components must also be checked for external damage. Repair damaged or corroded pins if possible, otherwise replace affected pins. Repair damaged wire or replace.