C1083-VACUUM PRESSURE SENSOR PERFORMANCE
C1083-VACUUM PRESSURE SENSOR PERFORMANCE
For a complete wiring diagram, refer to the Wiring Information.
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When Monitored:
With the ignition on and engine running for five minutes.
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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.
Possible Causes |
|---|
| VACUUM PRESSURE SENSOR |
| BRAKE VACUUM BOOSTER |
| ANTI-LOCK BRAKE SYSTEM (ABS) MODULE |
| 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. (Refer to 28 - DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure).
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. (Refer to 28 - DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure).
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. (Refer to 28 - DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure).
| 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 05 - Brakes/Hydraulic/Mechanical/BOOSTER, Power Brake - Removal) .
- Perform the ABS VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure).
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 in accordance with the Service Information. (Refer to 05 - Brakes/Electrical/PUMP, Electric Vacuum - Removal) .
- Perform the ABS VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure).
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. (Refer to 28 - DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - 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 08 - Electrical/8E - Electronic Control Modules/MODULE, Anti-Lock Brake System - Removal) .
- Perform the ABS VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure).
No