GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The solenoid relay is an internal part of the electronic brake control module (EBCM).

Battery voltage is supplied from terminals 1 and 2 for the relay switch at all times. When the ignition switch is turned ON, battery voltage from terminal 13 is supplied to the relay coil.

The EBCM will then ground the relay coil circuit to switch the relay ON, this supplies the solenoids and the motor with battery voltage. The relay will remain in the ON position as long as the ignition switch remains ON, or a DTC is set which turns OFF the relay.

Conditions for Setting the DTC

DTC C0014 will set after the ignition switch is ON, and the EBCM commands the relay ON, if the ignition voltage is greater than 10.5 volts and the switched relay voltage drops less than 8 volts for 1/4 of a second.

Action Taken When the DTC Sets

    • The solenoid relay is commanded OFF, removing the battery voltage from all the solenoids and the pump motor.
    • ABS disabled, ABS warning lamp is turned ON.

Conditions for Clearing the DTC

    • If the conditions that set the DTC C0014 are no longer present, the DTC may be cleared by using the proper scan tool.
    • The DTC that has not occurred in 100 drive cycles will be cleared from the history data.

Diagnostic Aids

Typical causes of DTC C0014:

    • Weak or discharged battery
    • Loose or corroded battery terminals
    • Engine block ground from battery poor
    • Poor or loose ABS fuse contacts
    • Poor EBCM terminals 1, 2, 13, 21
    • Low voltage to the EBCM terminals 1 and/or 2.
    • Internal EBCM failure

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - ABS?

--

Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Load test the battery. Refer to Battery Inspection/Test in Engine Electrical.
  2. Inspect the charging system. Refer to Charging System Test in Engine Electrical.
  3. Perform a parasitic load test.

Did the battery, charging system, and parasitic load test pass?

--

Go to Step 4

Go to Step 3

3

  1. Repair the charging system.
  2. Recharge the charging system, if necessary.
  3. Replace the battery. Refer to Battery and Battery Tray Replacement in Engine Electrical.
  4. Find and repair the source of the excessive parasitic draw, if necessary.

Did you find and correct the condition?

--

System OK

--

4

  1. Turn the ignition switch OFF.
  2. Disconnect the battery positive and negative terminals.
  3. Inspect the following for a poor connection:
  4. • Battery terminal cables
    • Negative cable to block and/or chassis
    • Positive cable to starter solenoid and/or junction block
    • EBCM terminals 1, 2, 13, 21
    • EBCM ground wire to chassis ground.

Were all the above connections satisfactory?

--

Go to Step 6

Go to Step 5

5

Repair the terminal and/or connections, as needed.

Did you find and correct the condition?

--

System OK

--

6

  1. The EBCM is still disconnected.
  2. Battery cables are still disconnected.
  3. Connect an ohmmeter to terminal C of the EBCM harness and the negative battery cable.

Was the resistance measured less than the specified value?

2 ohms

Go to Step 8

Go to Step 7

7

Find and repair the source of high resistance between the negative battery cable and the EBCM harness connector.

Did you find and correct the condition?

--

System OK

--

8

  1. Reconnect the battery cables.
  2. The EBCM is still disconnected.
  3. Turn the Ignition switch ON.
  4. Using a voltmeter, measure the voltage on the EBCM harness terminals, 1, 2, 13.

Was the voltage on all 3 terminals above the specified value.

B+

Go to Step 10

Go to Step 9

9

Find and repair the source of low voltage to the EBCM terminals.

Did you find and correct the condition?

--

System OK

--

10

Replace the EBCM. Refer to Brake Pressure Modulator Valve Assembly Replacement .

Did you complete the replacement?

--

System OK

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