Cadillac specific DTC OBD2 code: P1644 TP Output Circuit
Cadillac specific DTC OBD2 code: P1643 Engine Speed Output Circuit
Cadillac specific DTC OBD2 code: P1642 FC Relay 2 And 3 Control Circuit
Cadillac specific DTC OBD2 code: P1641 FC Relay 1 Control Circuit
Cadillac specific DTC OBD2 code: P1640 Driver 1-Input High Voltage
Cadillac specific DTC OBD2 code: P1639 5 Volt Reference 2 Circuit
Cadillac specific DTC OBD2 code: P1638 Generator F-Terminal Circuit
Cadillac specific DTC OBD2 code: P1637 Generator L-Terminal Circuit
Cadillac specific DTC OBD2 code: P1636 PCM Stack Overrun
Cadillac specific DTC OBD2 code: P1635 5 Volt Reference 1 Circuit