Diagnostic Chart (Functional Check)

Chart C-8B, Shift Solenoid Functional Check (4T60E Transaxle) Using Transaxle Test Box:

Torque Converter Clutch (TCC) Circuit:

Shift Solenoid Operating Sequence:

CIRCUIT DESCRIPTION
The 4T60E transaxle uses shift A solenoid and shift B solenoid to control shifting. Refer to table for solenoid operating sequence. The PCM monitors the TP sensor, vehicle speed and engine speed to determine the correct shift points.

If the trans range switch PRNDL inputs indicate manual low position, the PCM will keep both shift solenoids energized until 5400 RPM at which point the PCM will force a shift by de-energizing the shift A solenoid. Manual 2nd and manual 3rd are controlled hydraulically within the transaxle.

TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. With key "ON"/engine "OFF," the PCM should be commanding 1st gear (both shift solenoid control circuits grounded.)
2. Ensures that the PCM can control the ground to shift A solenoid properly.
3. Ensures that the PCM can control the ground to shift B solenoid.
4. Do not measure resistance until the ignition has been "OFF" for at least 10 seconds to ensure that the PCM has powered down completely.

DIAGNOSTIC AIDS
^ If the PCM, control circuitry, and shift solenoids are functioning properly and the transaxle still does not shift correctly, the problem may be hydraulic or mechanical.
^ 4th gear may be disabled and transaxle shift timing altered if the vehicle is operating in "Hot Mode." "Hot Mode" will be in effect when transaxle temperature exceeds 130°C (266°F).