C1082-02

C1082-02-VACUUM PRESSURE SENSOR - PERFORMANCE OR INCORRECT OPERATION

For a complete wiring diagram, refer to the Wiring Information.





- When Monitored:
With the ignition on and engine running for five minutes.

- Set Condition:
When the Anti-Lock Brake Module detects that the vacuum sensor signal does not make sense based on other vehicle conditions. No signal change, signal rapid change, unexpected change.





Diagnostic Test

1. VACUUM PRESSURE SIGNAL
1. Start the engine.
2. With the scan tool, view and record the vacuum pressure signal with no brake applied.
3. Turn the engine off.
4. Ignition on.
5. With the scan tool, view and record the vacuum pressure with no brake applied.

Is the vacuum pressure signal staying consistent?

Yes

- Go To 2

No

- Go To 4

2. MEASURE THE VACUUM PRESSURE SIGNAL
1. Start the engine.
2. Measure the vacuum pressure while pressing the brake pedal several times.
3. Turn the engine off.
4. Ignition on.

Does the vacuum drop below 14 mbar (2 psi)?

Yes

- Go To 3

No

- Perform the ABS-INTERMITTENT CONDITION TEST. ABS Intermittent Condition Test.

3. CHECK FOR VACUUM PRESSURE SIGNAL CHANGE
1. Turn the ignition on.
2. Remove the Vacuum Pressure Sensor from the Booster.
3. Connect a vacuum pump to the Vacuum Pressure Sensor.
4. Apply vacuum to the Vacuum Pressure Sensor and watch for signal change.

Is the vacuum pressure signal changing on the scan tool as vacuum is being applied?

Yes

- Go To 4

No

- Replace the Vacuum Pressure Sensor.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.

4. CHECK BRAKE BOOSTER CHECK VALVE
1. Remove the Brake Booster Check Valve.
2. Apply vacuum to the booster side of the check valve.

Is the Brake Booster Check Valve holding vacuum?

Yes

- Go To 5

No

- Replace the Brake Booster Check Valve.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.

5. CHECK BRAKE BOOSTER
1. Reinstall the Brake Booster Check Valve.
2. using a vacuum pump apply vacuum to the Brake Booster.

Is the Brake Booster holding vacuum?

Yes

- Go To 6

No

- Replace the Power Brake Booster. Power Brake Booster - Removal.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.

6. (3.6L) ENGINE WITH ELECTRIC VACUUM PUMP
1. Verify vehicle is equipped with a 3.6L engine and an electric vacuum pump.

Is the vehicle is equipped with a 3.6L engine and an electric vacuum pump?

Yes

- Replace the Electric Vacuum Pump.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.

No

- Go To 7

7. ANTI-LOCK BRAKE SYSTEM (ABS) MODULE
1. Turn the ignition off to the lock position.
2. Replace the Vacuum Pressure Sensor.
3. Perform the ABS VERIFICATION TEST. ABS Verification Test.
4. With the scan tool, read the DTCs.

Does the DTC remain active?

Yes

- Replace the Anti-Lock Brake System (ABS) Module. Anti-Lock Brake System Module - Removal.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time.