Road Test: Notes
WARNING: This page is about a different car, the 2023 GMC Sierra 3500 HD and 2023 GMC Sierra 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
The following test provides a method of evaluating the condition of the automatic transmission. The test is structured so that most driving conditions would be achieved. The test is divided into the following parts:
- Electrical Function Check
- Upshift Control and Torque Converter Clutch (TCC) Apply
- Part Throttle Step-In Downshifts
- Manual Downshifts
- Coasting Downshifts
- Manual Gear Range Selection
- REVERSE
- Driver Shift Control
NOTE:
Complete the test in the sequence given. Incomplete testing cannot guarantee an accurate evaluation.
Before the road test, ensure the following:
- The engine is performing properly.
- Transmission fluid level is correct. Refer to Transmission Fluid Level and Condition Check .
- Tire pressure is correct.
During the road test:
- Perform the test only when traffic conditions permit.
- Operate the vehicle in a controlled, safe manner.
- Observe all traffic regulations.
- View the scan tool data while conducting this test.
Take along qualified help in order to operate the vehicle safely.
- Observe any unusual sounds or smells.
After the road test, check the following:
- Inspect for proper transmission fluid level. Refer to Transmission Fluid Level and Condition Check .
- Inspect for any diagnostic trouble codes (DTCs) that may have set during the testing. Refer to the applicable DTC.
- Monitor the scan tool data for any abnormal readings or data.
- Inspect for fluid leaks. Refer to Fluid Leak Diagnosis .