Road Test. Cadillac Concours 1997

For 1990-2009 cars

• | Perform the road test using the Scan Tool Diagnostics.

• | Perform this test only when traffic and road conditions permit.

• | Observe all traffic safety regulations.

Conduct the test according to the following steps:

1. Start the engine.
2. Depress the brake pedal.

Important: Gear selections should be immediate and not harsh.

3. Move the gear selector between the following positions:

3.1. | Park to Reverse

3.2. | Reverse to Neutral

3.3. | Neutral to D4

4. Perform the same test procedure as instructed previously in the road test:

• | Upshifts and TCC Apply

• | Part Throttle Detent Downshift

• | Full Throttle Detent Downshift

• | Coasting Downshifts

• | Manual Gear Range Selection

Using the scan tool, DTC INFO, see if any transmission malfunction codes have been set. If so, refer to Functional Test . After repairing the vehicle, perform the road test and verify that no codes have been set again.

If no codes have been set and the condition remains, refer to Symptom Tables.

If the condition is suspected to originate in the torque converter, refer to Torque Converter Clutch Evaluation and Diagnosis .

### Upshift Control and Torque Converter Clutch (TCC) Apply

The PCM calculates the upshift points based primarily upon two inputs:

• | Throttle angle

• | Vehicle speed

When the PCM indicates that a shift should occur, an electrical signal is sent to the shift solenoids, which in turn move the valves to perform the upshift.

The shift speed charts refer to THROTTLE ANGLE instead of MIN THROTTLE or WOT in order to make shift speed measurement more uniform and accurate. Monitor THROTTLE ANGLE by using the scan tool.

With gear selector in D4, perform the following steps:

1. Refer to Shift Speed and choose a throttle position of either 10% or 25%.
2. Monitor the throttle position with the scan tool.
3. Accelerate to the chosen throttle position. Hold the throttle steady.

Important: Shift speeds may vary due to slight hydraulic delays in responding to electronic controls. A change from the original equipment tire size also affects shift speeds.

4. As the transmission upshifts, note the shift speed for each of the following gears:

• | 2nd gear

• | 3rd gear

• | 4th gear

5. The Torque Converter Clutch (TCC/VCC) should apply in Third or Fourth gear. Note when the TCC/VCC applies. If you do not notice the apply by an RPM drop, refer to Torque Converter Clutch Evaluation and Diagnosis .
6. Repeat steps 1-5 using several different throttle angles.

### Part Throttle Detent Downshift

At vehicle speeds of 64-88 km/h (40-55 mph) in Fourth gear, quickly increase the throttle angle. Verify the following results:

• | The TCC releases.

• | The transmission downshifts to 3rd gear immediately.

• | The 1-2 Shift Solenoid valve turns OFF.

• | The 2-3 Shift Solenoid valve remains ON.

### Full Throttle Detent Downshift

At vehicle speeds of 64-88 km/h (40-55 mph) in Fourth gear, quickly increase the throttle angle to its maximum position. Verify the following results:

• | The TCC releases.

• | The transmission downshifts to 2nd gear immediately.

• | The 1-2 and 2-3 Shift Solenoid valves turn OFF.

### Manual Downshifts

The shift solenoid valves do not control the initial downshift during manual downshifts. All manual downshifts are hydraulic. The solenoid states will change during, or shortly after, a manual downshift is selected.

1. At vehicle speeds of 64-88 km/h (40-55 mph) in Fourth gear, release the accelerator pedal while moving the gear selector to D3. Observe the following results:

• | The TCC releases.

• | The transmission downshifts to 3rd gear immediately.

2. Move the gear selector back to D4 and accelerate to 64-72 km/h (40-45 mph). Release the accelerator while moving the gear selector to D2 and observe the following results:

• | The TCC releases.

• | The transmission immediately downshifts to 2nd gear.

• | The engine slows the vehicle down.

3. Move the gear selector back to D4 and accelerate to 48 km/h (30 mph). Release the accelerator pedal while moving the gear selector to D1 and observe the following results:

• | The TCC releases.

• | The transmission immediately downshifts to 2nd gear, then to 1st gear.

• | The engine slows the vehicle down.

### Coasting Downshifts

1. With the gear selector in D4, accelerate to 4th gear with the TCC applied.
2. Release the accelerator pedal and lightly apply the brakes. Observe the following results:

• | The TCC releases.

• | Downshifts occur at speeds shown on the Shift Speed Chart. Refer to Shift Speed .

### Manual Gear Range Selection

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

Perform the following tests by accelerating at 10-15 degrees TPS.

#### Manual Third (D3)

With the vehicle stopped, move the gear selector to D3 and accelerate in order to observe the following conditions:

• | The 1-2 shift

• | The 2-3 shift

#### Manual Second (D2)

• | With the vehicle stopped, move the gear selector to D2 and accelerate in order to observe the 1-2 shift.

• | Accelerate to 40 km/h (25 mph) and observe the following conditions:

- | The 2-3 shift does not occur.

- | The TCC does not apply.

#### Manual First (D1)

With the vehicle stopped, move the gear selector to D1. Accelerate to 32 km/h (20 mph) and observe the following conditions:

• | No upshifts occur.

• | The TCC does not apply.

#### Reverse (R)

With the vehicle stopped, move the gear selector to R and slowly accelerate in order to observe the following conditions:

• | The 1-2 Shift Solenoid valve is ON.

• | The 2-3 Shift Solenoid valve is OFF.

Refer to Diagnostic Trouble Codes and repair the vehicle as directed. After repairing the vehicle, road test the vehicle and verify that the code did not set again.

If the transmission is still not performing well but no trouble codes have set, there may be an intermittent condition. Check all electrical connections for damage or a loose fit. This vehicle's diagnostic system is equipped with a snapshot test which can help catch an intermittent condition that does not occur long enough to set a code.

Refer to Electronic Component Description in order to become familiar with transmission conditions caused by transmission electrical malfunctions.

If no trouble codes set and the condition is suspected to be hydraulic, take the vehicle on a road test. Be sure to observe the following safety precautions: