Circuit/System Testing

Engine ON, apply the parking brake, select P (park) using the Shift Control.
Observe the scan tool Transmission ISS parameter. The reading should be within 400-800 RPM.
- If the ISS parameter is not within the specified range, test or replace the Transmission Input Speed Sensor (ISS). Refer to the INPUT SPEED SENSOR REPLACEMENT .
Perform a line pressure test. refer to LINE PRESSURE CHECK procedure.
Remove the control valve body cover. refer to CONTROL VALVE BODY COVER REMOVAL .
Inspect the inside of the control valve body cover for excessive sediment. There should not be excessive sediment.
- If excessive sediment is found inspect and replace as necessary the Torque converter assembly, Input shaft, and Fluid pump stator shaft assembly. refer to TORQUE CONVERTER ASSEMBLY REMOVAL , FORWARD AND DIRECT CLUTCH ASSEMBLY ASSEMBLE and FLUID PUMP CLEANING AND INSPECTION . If all conditions test normal, test or replace the transmission.
Verify that the control valve body has been serviced within the past 3 months.
- If the control valve body has not been serviced, replace the control valve body assembly. refer to CONTROL VALVE BODY REPLACEMENT procedure. If all circuits and components test normal, replace the transmission.
If all circuits and components test normal, replace the transmission.