For 1990-2009 cars
ABS Components
Antilock Brake System Schematics
Power Distribution Schematics
Power Distribution Schematics
Power Distribution Schematics
Power Distribution Schematics
Handling Electrostatic Discharge Sensitive Parts Notice

### Circuit Description

The pump motor is an integral part of the Brake Pressure Modulator Valve (BPMV). The electronic brake control relay supplies power to the solenoid valves and pump motor. This voltage is referred to as the system voltage. The electronic brake control relay, located in the EBCM, is activated whenever the ignition switch is in the ON position and no faults are present. The electronic brake control relay remains engaged until the ignition switch is turned off or a failure is detected.

### Conditions for Running the DTC

• | The system voltage is greater than 8.0 volts.

• | The system relay is ON.

• | The pump motor is commanded OFF.

### Conditions for Setting the DTC

The voltage across the pump motor is between 1.67 and 10.16 volts for 2.0 seconds.

### Action Taken When the DTC Sets

• | ABS/TCS is disabled.

• | ABS/TCS indicators are turned on.

### Conditions for Clearing the DTC

• | Condition for DTC is no longer present and scan tool clear DTC function is used.

• | 100 ignition cycles have passed with no DTCs detected.

### Diagnostic Aids

• | Possible causes for DTC C1242 to set are:

- | The pump motor internals has a open.

- | The pump motor circuit is open.

• | The pump motor is part of Brake Pressure Modulator Valve (BPMV) and is not serviceable separately.

• | The solenoid valve control relay is integral to the EBCM and is not serviceable separately.

• | 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.

• | If an intermittent malfunction exists refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the ABS Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check - ABS
2 |

1. Turn OFF the ignition.
2. Disconnect the EBCM connector.
3. Connect the J 39700 Universal Pinout Box using the J 39700-99 Cable Adapter to the EBCM harness connector only.
4. Measure the resistance between the pump motor ground circuit of the Universal Pinout Box and a known good ground.

Does the resistance measure within the specified value(s)?

0-2 ohms

Go to Step 4

Go to Step 3

3 | Repair open or high resistance in the pump motor ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 9 | --
4 |

1. Remove the EBCM from the BPMV. Refer to Electronic Brake Control Module Replacement .
2. Inspect the EBCM to BPMV connector for conditions which could cause intermittents, such as damage, corrosion, poor terminal contact, or presence of brake fluid.

Is the connector OK and cavity free of brake fluid?

--

Go to Step 6

Go to Step 5

5 |

1. If connector corrosion or damage is evident, replace BPMV and/or EBCM as necessary.
2. If brake fluid is present, replace both BPMV and EBCM. Refer to Brake Pressure Modulator Valve Replacement and Electronic Brake Control Module Replacement .

Did you complete the repair?

--

Go to Step 9

--

6 | Measure the resistance between the pump motor terminals using the J 35616 Connector Test Adapter Kit . Remember to zero DMM first before proceeding with this test. Is the resistance within the specified range? | 0-2 ohms | Go to Step 7 | Go to Step 8
7 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement . Did you complete the repair? | -- | Go to Step 9 | --
8 | Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement . Did you complete the repair? | -- | Go to Step 9 | --
9 |

1. Use the scan tool in order to clear the DTCs.
2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK