Automatic Transmission Auxiliary Fluid Accumulator - If Equipped
The Transmission Fluid Pressure Accumulator Solenoid Valve is part of the Stop/Start system on the vehicle. The automatic transmission auxiliary fluid accumulator is used to supply transmission fluid line pressure to the appropriate clutches for an auto start event. Attached to the accumulator is a normally closed ON/OFF solenoid. When the ignition is ON, the engine control ignition relay supplies 12 V to the accumulator solenoid. To complete the circuit, the transmission control module (TCM) supplies a control circuit to the accumulator solenoid. When the engine control module (ECM) requests an auto start event, a serial data message is sent to the TCM, to command the solenoid ON. This allows captured pressurized fluid to exit the accumulator to apply the clutches for a 1st gear start.