Circuit Description
The pump motor circuit is integral to the BPMV. The EBCM internal relay is commanded ON in order to supply battery voltage to the high side of the pump motor. The EBCM microprocessor grounds the low side of the pump motor when activation of the pump motor is required.
Conditions for Running the DTC
| • | Ignition switch in the RUN position. |
| • | The EBCM internal relay is commanded ON. |
Conditions for Setting the DTC (C0267)
| • | The pump motor is off |
| • | Low voltage is present from the low side of the pump motor when high voltage is expected |
Conditions for Setting the DTC (C0268)
| • | The EBCM internal relay is on |
| • | The pump motor is commanded ON and then OFF |
| • | High voltage exists from the low side of the pump motor for 100 ms when the voltage is expected to be low |
Action Taken When the DTC Sets
| • | The ABS indicator lamp turns on |
| • | The ABS disables |
Malfunction responses to DTC C0267/68 vary, depending on the affected subsystem.
| • | ABS--Ignition latched |
| • | DRP--DRP non critical |
For a detailed explanation of DTC malfunction responses, refer to Self-Diagnostics .
Conditions for Clearing the DTC
| • | Repair the conditions responsible for setting the DTC. |
| • | Use the Clear DTCs function on the Scan Tool |
Diagnostic Aids
The pump motor is integral with the BPMV. Do not service the pump motor separately. A poor power/ground connection at the 2-way EBCM connector or the 2-way motor harness from the EBCM to the pump motor can cause a DTC C0267. A seized pump motor, shorted pump motor windings or a poor power/ground at the 2-way EBCM connector can cause a DTC C0268. Replace the EBCM or the BPMV if the following tests show that the pump motor EBCM internal circuits have failed.
Important: Reset the DMM test leads to zero prior to making any resistance measurements. Refer to the DMM manual for instructions.
Test Description
The numbers below refer to the steps in the diagnostic table:
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check |
2 |
Is the connector and the wiring in good condition? | -- | Go to Step 3 | Go to Step 4 |
Measure the resistance between terminal A and terminal B of the 2-way pump motor pigtail connector using a DMM. Reset the DMM test leads to zero prior to making this resistance measurement. Does the resistance measure within the specified range? | 0.1-1.0ohms | Go to Step 5 | Go to Step 6 | |
4 | Repair the 2-way pump motor pigtail connector or wiring if necessary. Did you find and correct the condition? | -- | Go to Step 7 | -- |
5 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Did you complete the replacement? | -- | Go to Step 7 | -- |
6 | Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement . Did you complete the replacement? | -- | Go to Step 7 | -- |
7 | Operate the vehicle under the conditions for running the DTC as specified in the supporting text. Does the DTC set? | -- | Go to Step 2 | System OK |
