Chart C-8B Shift Solenoid Functional Check (4T60E Transaxle)

Chart C-8B:

Transmission Harness Schematic:

Shift Solenoid Operating Sequence:

CIRCUIT DESCRIPTION
The 4T60E transaxle uses shift solenoid "A" and shift solenoid "B" to control shifting. Refer to table for solenoid operating sequence. The Powertrain Control Module (PCM) monitors the Throttle Position Sensor (TPS) and vehicle speed vs. engine speed to determine the correct shift points. If the transaxle range switch indicates manual low position, the PCM will keep both solenoids "A" and "B" energized until 5400 RPM at which point the PCM will force a shift by de-energizing solenoid "A." Manual 2nd and manual 3rd are controlled hydraulically within the transaxle.

TEST DESCRIPTION
Numbers below refer to circled numbers on the diagnostic chart.

1. Checks availability of battery voltage on circuit 439, and integrity of circuit 1222 and circuit 1223.
2. Checks the PCM's capability to turn shift solenoid "A" "ON," and "OFF."
3. Checks the PCM's capability to turn shift solenoid "B" "ON,"and"OFF."
4. Determines if shift solenoid "A" and shift solenoid "B" resistance values are within range specifications in chart.

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.