Electrical/Garage Shift Test

This test should be performed before a road test to ensure electrical control inputs are connected and operating. If inputs are not checked before operating the transmission, a simple electrical condition could be misdiagnosed as a serious transmission problem. A scan tool provides important information and must be used for accurate diagnosis.

1. Move gear selector to Park and set parking brake.

2. Connect scan tool to DLC terminal.

3. Start engine.

4. Connect power to scan tool.

5. Verify that the following inputs are present:

a. Input speed.

b. Output speed.

c. Vehicle speed.

d. PRND select.

e. Current gear.

f. Desired pressure control sol.

g. Actual pressure control sol.

h. Coolant temperature.

i. Transmission temperature.

j. Throttle angle.

k. TCC duty cycle.

l. System voltage.

m. Brake switch.

6. Monitor brake switch signal while tapping on brake pedal. Brake switch should be On when brake pedal is depressed and come Off when brake pedal is released.

7. Monitor PRNDL select signal and move gear selector through all ranges. Verify that PRNDL select value matches gear range indicated on instrument panel or console. Gear selection should be immediate and not harsh.

8. Move gear selector to Neutral and monitor throttle angle signal while increasing and decreasing engine RPM with accelerator pedal. Throttle angle should increase with engine RPM.