P1634 Diagnostic Trouble Code (7 interpretations)

The control module detected improper operation of the Data Output Link circuit. This is the manufacturer-specific definition used by Ford.

The control module detected improper operation of the Motor power inverter module circuit. This is the manufacturer-specific definition used by Honda.

The control module detected a fault associated with the Auxiliary Heater Relay Short or Open circuit or function; the stored code identifies the affected component rather than a single failure mode. This is the manufacturer-specific definition used by Hyundai.

The control module detected an interruption (open circuit) in the Generator terminal B circuit, so the expected electrical continuity was not present. This is the manufacturer-specific definition used by Mazda.

The control module detected the fault condition "ECU internal fault" for the Engine ECU. Documented for the Bosch EDC16C34 injection ECU (DV6TED4 1.6 HDi) on Peugeot applications; the same PSA control units are also fitted to Citroën models.

The control module detected that the Accelerator pedal position (APP) sensor 2 signal stayed above the expected range. This is the manufacturer-specific definition used by Audi.

The control module detected that the Accelerator Position Sensor 2 (G185) value was above the expected limit. This is the manufacturer-specific definition used by Volkswagen. Volkswagen Group tools also report it as fault code 18042. Documented across Volkswagen Group applications (Audi, SEAT and Škoda included).