Chart C-12 Charge Air Cooler (CAC) Pump

CIRCUIT DESCRIPTION
Battery voltage to operate the CAC pump motor is supplied to relay terminal "D." Ignition voltage to energize the relay is supplied to relay terminal "A." When the ECM grounds CKT 901, the relay is energized and the CAC pump is turned "ON." When the engine is running, the ECM will turn the CAC pump "ON" if the conditions for a coolant temperature sensor trouble code (Code 14 or 15) are present or if the coolant temperature is greater than 108°C (230°F).

DIAGNOSTIC AIDS
If the vehicle is experiencing poor performance, it may be due to a malfunctioning CAC pump. Refer to diagnostic chart.