Circuit Description
The electronic brake control module (EBCM) turns ON the tire pressure warning indicator by opening the tire pressure warning indicator control circuit. The tire pressure warning indicator is connected to the GAUGE fuse. This circuit has power when the ignition switch is in the ON or START positions. When the ignition switch is turned to the ON position, the EBCM turns ON the tire pressure warning indicator for 3-4 seconds for a bulb check. If the EBCM detects a malfunction, the tire pressure warning indicator will stay ON to warn the driver that the tire pressure warning system is disabled and needs service.
Diagnostic Aids
Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.
The following are possible causes of the malfunction:
| • | An open in the tire pressure warning indicator control circuit |
| • | An open or short to ground in the ambient temperature circuit |
| • | Incorrect tire size |
| • | An internal EBCM malfunction |
| • | A malfunctioning instrument panel cluster (IPC) assembly |
If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step tests the ambient temperature sensor circuit for an open or short to ground.
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This step determines if the malfunction is caused by an internal EBCM malfunction.
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This step tests the tire pressure warning indicator control circuit for a short to ground.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Tire Pressure Monitoring System Schematics Connector End View Reference: Tire Pressure Monitoring System Connector End Views | |||
1 | Did you perform a Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 | Turn ON the ignition, with the engine OFF. Does the tire pressure warning indicator turn ON for 3-4 seconds and go OFF? | Go to Step 4 | Go to Step 3 |
3 | Do any of the other instrument cluster indicators or gages function? | Go to Step 3 | Go to Gages Inoperative - All |
4 | Check if the vehicle has the appropriate size tires. Did you find and correct the condition? | Go to Step 11 | Go to Step 5 |
5 | Is the instrument panel cluster (IPC) outside temperature reading equal to the actual outside temperature? | Go to Step 6 | Go to Outside Air Temperature Display Inaccurate or Inoperative |
Test the ambient temperature sensor circuit for an open or short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 11 | Go to Step 7 | |
Does the tire pressure warning indicator turn ON? | Go to Step 10 | Go to Step 8 | |
Test the tire pressure warning indicator control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 11 | Go to Step 9 | |
9 | Replace the instrument panel cluster assembly. Refer to Instrument Cluster Replacement . Did you complete the replacement? | Go to Step 11 | -- |
10 | Replace the brake pressure modulator valve (BPMV). Refer to Brake Pressure Modulator Valve Assembly Replacement . Is the repair complete? | Go to Step 11 | -- |
11 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
