Circuit Description
The system relay is energized when the ignition is ON. The system relay supplies voltage to the solenoid valves and the pump motor. This voltage is referred to as the system voltage.
The electronic brake control module (EBCM) controls each solenoid valve by grounding the solenoid.
The EBCM controls the pump motor by grounding the control circuit. The pump serves 2 purposes:
| • | Transfers brake fluid from the brake calipers to the master cylinder reservoir during pressure decrease events. |
| • | Transfers brake fluid from the master cylinder reservoir to the brake calipers during pressure increase events. |
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC C1217 Pump Motor Shorted to Ground
Conditions for Running the DTC
| • | The pump motor has been commanded OFF for 1 second. |
| • | The system voltage is greater than 9.36 volts. |
Conditions for Setting the DTC
One of the following conditions exists for 0.2 seconds:
| • | The voltage across the pump motor is greater than 10.2 volts. |
| • | The pump motor low side voltage is less than 2.7 volts. |
Action Taken When the DTC Sets
| • | The EBCM disables the ABS for the duration of the ignition cycle. |
| • | The ABS indicator turns ON. |
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present and the DTC is cleared with a scan tool. |
| • | The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
Diagnostic Aids
| • | This DTC determines if there is a short in the pump motor control circuit. |
| • | The pump motor is integral to the BPMV. The pump motor is not serviceable. |
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Value | Yes | No |
|---|---|---|---|---|
Schematic Reference: Antilock Brake System Schematics | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 3 |
Does the resistance measure less than the specified value? | 5 ohms | Go to Step 4 | Go to Step 5 | |
4 | Inspect for poor connections at the connector of the BPMV. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 6 |
5 | Inspect for poor connections at the harness connector of the EBCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 7 |
6 | Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement . Did you complete the repair? | -- | Go to Step 8 | -- |
7 | Replace the EBCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the repair? | -- | Go to Step 8 | -- |
8 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
