Diagnostic Test

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
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. Refer to STANDARD PROCEDURE .
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. Refer to STANDARD PROCEDURE .
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. Refer to STANDARD PROCEDURE .
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 in accordance with the Service Information. Refer to BOOSTER, POWER BRAKE, REMOVAL .
  - Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
(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 in accordance with the Service Information. Refer to PUMP, ELECTRIC VACUUM, REMOVAL .
  - Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 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. Refer to STANDARD PROCEDURE .
4. With the scan tool, read the DTCs.
  Does the DTC remain active?
  
  Yes
  - Replace the Anti-lock Brake System (ABS) Module in accordance with the Service Information. Refer to MODULE, ANTI-LOCK BRAKE SYSTEM, REMOVAL .
  - Perform the ABS VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Test complete, the condition or conditions that originally set this DTC are not present at this time.