DTC C1A27-12: Compressor Circuit - Circuit short to battery: Action

Refer to the electrical circuit diagrams and check the air suspension air supply unit isolation relay circuits for short circuit to ground. Repair circuit(s) as required, clear the DTCs and retest
Refer to the electrical circuit diagrams and check the air suspension air supply unit isolation relay high current terminals for short circuit to one another. Repair circuit(s) as required, clear the DTCs and retest
If the fault persists, install a new air suspension air supply unit isolation relay. Clear the DTCs and retest
If the fault persists, refer to the electrical circuit diagrams and check the air suspension air supply unit isolation relay circuits and terminals for short circuit to ground. Repair circuit(s) as required, clear the DTCs and retest
If the fault persists, install a new air suspension air supply unit isolation relay. Clear the DTCs and retest