Circuit/System Testing

Operate the vehicle in D.
Using the scan tool record the gear ratio while accelerating in 3rd gear. The gear ratio should be within 1.54:1-2.31:1.
- If the 3rd gear ratio is 1.45:1, inspect and repair the control valve body assembly for the following conditions. Refer to CONTROL VALVE BODY ASSEMBLY DISASSEMBLE .
- Stuck 2-3, 3-4 shift solenoid valve assembly
- Stuck M2 shift valve
  If the conditions test normal, replace the control valve body assembly, Refer to CONTROL VALVE BODY REPLACEMENT procedure.
  - If the 3rd gear ratio is 2.94:1, inspect and repair the control valve body assembly for the following conditions. Refer to CONTROL VALVE BODY ASSEMBLY DISASSEMBLE .
- Stuck 3-4, 4-5 shift solenoid valve assembly
- Stuck U1 shift valve
  If the conditions test normal, replace the control valve body assembly. Refer to CONTROL VALVE BODY REPLACEMENT procedure.
  
  If the 3rd gear ratio is not within the specified range and is not 1.45:1 or 2.94:1, continue to step 3.
Observe the scan tool Transmission OSS parameter while driving the vehicle. The reading should correspond to a known properly functioning OSS.
- If the OSS is malfunctioning, replace the Transmission Output Speed Sensor (OSS). Refer to the OUTPUT SPEED SENSOR REPLACEMENT procedure.
Stop the vehicle, apply the parking brake, engine at idle, 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, replace the Transmission Input Speed Sensor (ISS). Refer to the INPUT SPEED SENSOR REPLACEMENT procedure.
Ignition ON, engine OFF, command shift solenoid 1 ON and OFF with a scan tool. The solenoid should click when commanded ON.
- If the solenoid does not click, replace the 1st shift solenoid valve assembly. Refer to CONTROL VALVE BODY ASSEMBLY DISASSEMBLE .
Command shift solenoid 3 ON and OFF with a scan tool. The solenoid should click when commanded ON.
- If the solenoid does not click, replace the 1-2, 2-3, reverse shift solenoid valve assembly. Refer to CONTROL VALVE BODY ASSEMBLY DISASSEMBLE .
Command shift solenoid 5 ON and OFF with a scan tool. The solenoid should click when commanded ON.
- If the solenoid does not click, replace the reverse shift solenoid valve assembly. Refer to CONTROL VALVE BODY ASSEMBLY DISASSEMBLE .
Perform a line pressure test. Refer to LINE PRESSURE CHECK .
Remove the control valve body cover. Refer to CONTROL VALVE BODY COVER REMOVAL procedure.
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 3rd gear band and forward clutch. Refer to THIRD GEAR BAND ASSEMBLY INSTALLATION and FORWARD AND DIRECT CLUTCH ASSEMBLY ASSEMBLE .
Inspect the control valve body assembly for the following conditions. Refer to CONTROL VALVE REAR BODY DISASSEMBLE and MIDDLE CONTROL VALVE BODY DISASSEMBLE . The conditions should not be found.
- Stuck U1 shift valve
- Stuck M1 shift valve
- Stuck U2 shift valve
- Stuck shift pressure relay valve
- Stuck neutral relay valve
- Stuck line pressure control solenoid valve assembly
  If any of the above conditions are found, replace the valve body assembly. Refer to CONTROL VALVE BODY REPLACEMENT procedure.
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 .
If all circuits and components test normal, replace the transmission.