Fluid Pressure Sensor/Switch: Service and Repair

Pressure Switch Manifold Replacement

Removal Procedure





Note: Individual pressure switches cannot be replaced. When any pressure switch needs replacing, the entire assembly must be replaced.

Note: The modulated main pressure (MAIN MOD) solenoid has been removed for clarity.

1. Remove the oil pan and transmission internal oil filter. Refer to Oil Pan Replacement (Allison - Automatic Transmission).
Warning: Refer to Battery Disconnect Warning (Service Precautions).

2. Disconnect the internal wiring harness connector from the transmission fluid pressure (TFP) switch (2).
3. Remove six bolts (1). Remove the TFP switch (2).

Installation Procedure





Caution: Refer to Fastener Caution (Fastener Caution).

1. Place the new TFP manifold assembly (2) in position and install one bolt (1) in a recessed location to hold in position. Start the remaining five bolts (1) in recessed locations and tighten the bolts by hand.

Torque the bolts to 12 Nm (108 lb in).

2. Connect the internal wiring harness connector to the TFP switch.
3. Install the oil pan and transmission internal oil filter. Refer to Oil Pan Replacement (Allison - Automatic Transmission).

Note: The FastLearn, adapt, procedure must be performed. This can be done in 1 step using a scan tool. If this procedure is not done, the TCM adaptive values will be at the settings that it learned for the old components and will be in slow adaptive mode. Under these conditions, it will take an unacceptably long time for the adaptive values to converge to levels suitable for the new transmission.

4. Perform the FastLearn procedure. Refer to FastLearn Procedure (Allison - Automatic Transmission).