Circuit/System Testing
WARNING: This page is about a different variant/trim than selected.
- Operate the vehicle in 2nd gear. The engine should not stall when shifting into 2nd gear.
- Inspect and repair as necessary, the control valve body assembly for a stuck 3-4, 4-5 solenoid valve or a stuck U1 shift valve. Refer to the Control Valve Body Assembly Disassemble procedure.
- 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.
- 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 Direct clutch, Low and reverse clutch, and 1-2, reverse clutch. Refer to Forward and Direct Clutch Assembly Assemble , Front Internal Gear and Low and Reverse Clutch Installation , and 1-2 Reverse Clutch Assemble procedures.
- Inspect the control valve body assembly for the following conditions. Refer to Control Valve Rear Body Disassemble
and Control Valve Body Disassemble - Middle
. The conditions should not be found.
- Stuck U1 shift valve
- Stuck M1 shift valve
- Stuck U2 shift 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 procedure.
- If all circuits and components test normal, replace the transmission.