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:

1. Electrical Function Check
2. Upshift Control and Torque Converter Clutch (TCC) Apply
3. Part Throttle Detent Downshifts
4. Full Throttle Detent Downshifts Manual Downshifts
5. Coasting Downshifts
6. Manual Gear Range Selection

•

Reverse

•	Manual First

•	Manual Second

•	Manual Third

Important: 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 Check.

-	Tire pressures are 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

-	Take an assistant to view the Tech 2 data while conducting this test

-	Observe any unusual sounds or smells

•	After the road test, check the following:

-	Transmission fluid level--Refer to Transmission Fluid Check.

-	Diagnostic Trouble Codes (DTC's) that may have set during the test. Refer to Diagnostic Trouble Code (DTC) List/Type.

-	Tech 2 data for any abnormal readings or information.

Perform this check firs, in order to ensure the electronic transmission components are connected and functioning properly. If these components are not checked, a simple electrical condition could be incorrectly diagnosed.

1. Connect Tech 2
2. Set the parking brake and ensure the gear selector is in Park
3. Start the engine.
4. Verify that the following Tech 2 data can be obtained and is functioning properly. Data that is questionable may indicate a concern. Refer to Scan Tool Data List in Section 7D2 Automatic Transmission-4L65E-Electrical Diagnosis for Alloytec, or Section 6C3-2 Powertrain Management-GEN III V8-Diagnostics.

•	Engine Speed

•	Transmission output speed

•	Vehicle speed

•	TFP manual valve position switch

•	Transmission range (engine list)

•	Commanded gear (current gear)

•	PC solenoid reference current

•	PC solenoid actual current

•	PC solenoid duty cycle

•	Brake switch

•	Engine coolant temperature

•	Transmission fluid temperature

•	Throttle angle

•	Ignition voltage

•	1-2 shift solenoid (A)

•	2-3 shift solenoid (B)

•	TCC solenoid duty cycle

•	TCC slip speed

5. Monitor the brake switch signal while depressing and releasing the brake pedal. Tech 2 should display:

•	Closed when the brake pedal is released.

•	Open when the brake pedal is depressed.

6. Apply the brake pedal and ensure that the parking brake is set.
7. Check the garage shifts by moving the gear selector through the following ranges:

•	Park to Reverse

•	Reverse to Neutral

•	Neutral to Drive

•	Pause two to three seconds in each gear position.

8. Verify the gear engagements are immediate.

Important: Soft or delayed engagement may be caused by any of the following conditions:

•	Low idle speed. Compare engine idle speed to desired idle speed.

•	Low fluid level.

•	Commanded high PC solenoid current. Compare PC solenoid reference.

•	Current to PC solenoid actual current.

•	Cold transmission fluid. Check for low transmission fluid temperature.

9. Verify the gear engagements are not harsh.

Important: Harsh engagement may be caused by any of the following conditions:

•	High idle speed. Compare engine idle speed to desired idle speed.

•	Commanded low PC solenoid current. Compare PC solenoid reference current to PC solenoid actual current.

•	A default condition caused by certain DTC's that result in maximum line pressure to prevent slippage.

10. Monitor transmission range on Tech 2.

•	Apply the brake pedal and ensure the parking brake is set.

•	Move the gear selector through all ranges.

•	Pause two to three seconds in each range.

•	Return gear selector to Park.

•	Verify that all selector positions match display on Tech 2.

11. Check throttle angle input.

•	Apply the brake pedal and ensure that the parking brake is set.

•	Ensure the gear selector is in Park.

•	Monitor pedal/throttle angle while increasing and decreasing engine speed with the pedal. The Tech 2 pedal/throttle angle display should increase and decrease with engine speed.

•	If any of the above checks do not perform properly, record the result for reference after completion of the road test.

The PCM calculates the upshift points based primarily on two inputs: pedal/throttle angle and vehicle speed. When the PCM determines that conditions are met for a shift to occur, the PCM commands the shift by closing or opening the earth circuit for the appropriate solenoid.

Perform the following steps:

1. Refer to Shift Speed for the appropriate shift pattern and engine configuration.
2. Monitor the following Tech 2 parameters:

•	Pedal/throttle angle

•	Vehicle speed

•	Engine speed

•	Output shaft speed

•	Commanded gear

•	Slip speed

•	Solenoid states

3. Place the gear selector in the Drive position.
4. Accelerate the vehicle using the chosen pedal/throttle angle and hold the pedal steady.
5. As the transmission upshifts, note the vehicle speed when the shift occurs for each gear change. There should be a noticeable shift feel or engine speed change within one to two seconds of the commanded gear change.
6. Compare the shift speeds to the shift charts. Shift speeds may vary slightly due to transmission fluid temperature or hydraulic delays in responding to electronic controls. (Note any harsh, soft or delayed shifts or slipping and any noise or vibration).
7. Repeat steps 1 through 6 to complete all shift patterns except Cruise Mode.
8. Check for TCC apply in Third and Fourth gear.

Important:  The TCC apply point. When the TCC applies, there should be a noticeable drop in engine speed and a drop slip speed to below 100 RPM. If the TCC apply can not be detected:

•	Check for DTCs

•	Refer to Torque Converter Diagnosis.

•	Refer to Shift Speed for the correct apply speeds.

•	Lightly tap and release the brake pedal. The TCC will release on most applications.

1. Place the gear selector in the Drive position.
2. Accelerate the vehicle to 64-88 km/h in Fourth gear.
3. Quickly increase pedal/throttle angle to greater than 50%.
4. Verify the following:

•	The TCC releases.

•	The transmission downshifts immediately to Third Gear.

1. Place the gear selector in the Drive position. Accelerate the vehicle to speeds of 64-88 km/h in Fourth gear.
2. Quickly increase pedal/throttle angle to 100% (WOT).
3. Verify the following:

•	The TCC releases.

•	The transmission downshifts immediately to Second gear.

The shift solenoid valves do not control the initial downshift for the 4-3 or the 3-2 manual downshifts as these are hydraulic.

The 2-1 manual downshift however, is electronic. The solenoid states should change during or shortly after a manual downshift is selected.

Manual 4-3 Downshift

1. Place the gear selector in the Drive position.
2. Accelerate the vehicle to 64-88 km/h in Fourth gear.
3. Release the throttle while moving the gear selector to Third.
4. Verify the following:

•	The TCC releases.

•	The transmission downshifts immediately to Third gear.

•	The engine slows the vehicle.

Manual 4-2 Downshift

1. Place the gear selector in the Drive position.
2. Accelerate the vehicle to 64-72 km/h.
3. Release the throttle while moving the gear selector to Second. Verify the following:

•	The TCC releases.

•	The transmission downshifts immediately to Second gear.

•	The engine slows the vehicle.

Manual 4-1 Downshift

1. Place the gear selector in the Drive position.
2. Accelerate the vehicle 48 km/h
3. Release the throttle while moving the gear selector to First.
4. Verify the following:

•	The TCC releases

•	The transmission downshifts immediately to First gear.

•	The engine slows the vehicle.

Coasting Downshifts

1. Place the gear selector in the Drive position.
2. Accelerate the vehicle to Fourth gear with the TCC applied. Release the throttle and lightly apply the brakes.
3. Verify the following:

•	The TCC releases.

•	Downshifts occur at speeds shown in the shift speed charts, refer to Shift Speed.

The shift solenoids control the upshifts in the manual gear ranges.

Perform the following tests using 10 to 15 percent pedal/throttle angle.

Reverse

1. With the vehicle stopped, move the gear selector to Reverse.
2. Slowly accelerate the vehicle.
3. Verify that there is no noticeable, slip, noise or vibration.

Manual First

1. With the vehicle stopped, move the gear selector to First.
2. Accelerate the vehicle to 32 km/h.
3. Verify the following:

•	No upshifts occur.

•	The TCC does not apply.

•	There is no noticeable slip, noise, or vibration.

Manual Second

1. With the vehicle stopped, move the gear selector to Second.
2. Accelerate the vehicle to 57 km/h
3. Verify the following:

•	The 1-2 shift occurs.

•	The 2-3 shift does not occur.

•	There is no noticeable slip, noise or vibration.

Manual Third

1. With the vehicle stopped, move the gear selector to Third.
2. Accelerate the vehicle to 64 km/h.
3. Verify the following:

•	The 1-2 shift occurs.

•	The 2-3 shift occurs.

•	There is no noticeable slip, noise or vibration.