Circuit Description
The EBCM/EBTCM and the BPMV receive power from 3 circuits. CKT 642 supplies battery power to the pump motor. CKT 342 supplies ignition power to the solenoid valves, the EBCM/EBTCM, and the pump motor relay coil. CKT 441 supplies battery power to initialize controller operations. CKT 441 also supplies power to the solenoid valve relay coil.
Conditions for Setting the DTC
| • | The ignition voltage is greater than 10.5 volts. |
| • | The solenoid relay is commanded ON. |
| • | The solenoid relay voltage is less than 8.0 volts. |
Action Taken When the DTC Sets
| • | A malfunction DTC is stored. |
| • | The ABS/TCS is disabled. |
| • | The ABS indicator isturned ON. |
| • | The TRACTION OFF indicator is turned ON. |
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present and you used the scan tool Clear DTC function. |
| • | The EBCM/EBTCM does not detect the DTC in 50 drive cycles. |
Diagnostic Aids
| • | It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction. |
| • | An intermittent malfunction can be caused by poor connections, broken insulation, or a wire that is broken inside the insulation. |
| • | If an intermittent malfunction exists, refer to Intermittents and Poor Connections Diagnosis in Wiring Systems. |
| • | The following conditions are possible causes of the malfunction: |
| - | A problem in the power distribution system may result in no battery voltage to CKT 342. |
| - | The ABS MOTOR fuse is open. |
| - | CKT 642 has a wiring problem, corrosion, or faulty connections. |
| - | There is an internal malfunction in the EBCM/EBTCM or the BPMV. |
| - | The solenoid valve relay is faulty. |
| • | The relays are integral to the EBCM/EBTCM and are not serviceable. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests for a short to ground in CKT 642.
-
This step tests for an internal short in the BPMV.
-
This step tests for an open in CKT 642.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the ABS Diagnostic System Check performed? | -- | Go to Step 2 | |
2 | Inspect the ABS MOTOR fuse in the underhood maxifuse block. Is the fuse OK? | -- | Go to Step 7 | Go to Step 3 |
3 |
Is the fuse OK? | -- | Go to Step 4 | |
Is the resistance equal to the specified value? | OL (Infinite) | Go to Step 5 | Go to Step 10 | |
Is the resistance equal to the specified value? | OL (Infinite) | Go to Step 9 | Go to Step 6 | |
6 | Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement . Is the repair complete? | -- | -- | |
7 |
Is the voltage equal to the specified value? | Battery Voltage | Go to Step 8 | Go to Wiring Repairs in Wiring Systems |
Is the voltage equal to the specified value? | Battery Voltage | Go to Step 9 | Go to Step 11 | |
9 | Replace the EBCM/EBTCM. Refer to Electronic Brake Control Module Replacement . Is the repair complete? | -- | -- | |
10 | Repair the short to ground in CKT 642. Refer to Wiring Repairs in Wiring Systems. Is the circuit repair complete? | -- | -- | |
11 | Repair the open or high resistance in CKT 642. Refer to Wiring Repairs in Wiring Systems. Is the circuit repair complete? | -- | -- |
