Shift Point Road Test

The Shift Point Road Test and Torque Converter Operation Test provide diagnostic information on transmission shift controls and torque converter operation.

Use NGS Tester to monitor transmission shift points. Install NGS before proceeding to the road test.
- Verify that the correct program card is inserted in NGS.
- Connect J1962/16-way DLC cable adapter to NGS.
- Connect NGS DLC cable adapter securely into the vehicle DLC.
- Turn the ignition switch to the ON position, or start the vehicle if necessary.
- Select VEHICLE & ENGINE SELECTION menu.
- Select NEW VEHICLE YEAR & MODEL.
- Enter year, engine, or model with the appropriate qualifier, if needed (for example, transmission, 49 State or California).
- Select DIAGNOSTIC DATA LINK.
- Select PCM-POWERTRAIN CONTROL MODULE.
- Select the PID DATA MONITOR AND RECORD.
- Select VSS, TFT, TCC, TSS, SS1, SS2, SS3.
Monitor and record the selected PIDs. Compare the recorded results with the shift point charts; refer to Overdrive Range Shift Point Chart, Drive Range Shift Point Chart, and Low Range Shift Point Chart.

Shift Point Road Test

CAUTION: Strict observance of the speed limit is mandatory.

This test verifies that the shift control system is operating correctly.
1. Bring the engine and transmission up to normal operating temperature 60° - 70°C (140° - 158°F).
2. Operate the vehicle with the gearshift lever in (D) position.

Overdrive Range Shift Point Chart:

Drive Range Shift Point Chart:

Low Range Shift Point Chart:

3. Apply minimum throttle and observe the speeds at which upshift occurs and torque converter engages; refer to the Shift Point Chart.

NOTE: Monitor throttle position sensor voltage. The signal should be constant and should increase as the throttle is increased.

NOTE: Monitor TP sensor voltage. The signal should be constant and should increase as the throttle is increased.

NOTE: Monitor TP sensor voltage. The signal should be constant and should increase as the throttle is increased.

4. For Clutch/Band Application.
5. Press the accelerator pedal to the floor, Wide Open Throttle (WOT). The transmission should shift from third gear to second gear, or from third gear to first gear depending on vehicle speed. The torque converter clutch should disengage and then reapply.
6. With the vehicle in the D position and the speed below 110 km/h (68 mph) and less than half throttle, move the gearshift lever from the D position to the L position and remove foot from the accelerator pedal. The transmission should immediately downshift into second gear. With the vehicle remaining in the L position, reduce the speed below 43 km/h (27 mph). The transmission should downshift into first gear.
7. If the transmission fails to upshift and downshift or the torque converter clutch does not apply and release, refer to Diagnosis by Symptom.Symptom Related Diagnostic Procedures