GM Service Manual Online
For 1990-2009 cars only

Object Number: 364086  Size: MF
ABS Components
Antilock Brake System Schematics
Power Distribution Schematics
Power Distribution Schematics
Power Distribution Schematics
Antilock Brake System Schematics
Data Link Connector Schematics
Handling Electrostatic Discharge Sensitive Parts Notice

Circuit Description

Ignition voltage is supplied through terminal C10 of the Electronic Brake Control Relay. The above condition enables the EBCM to energize the pull-in coil by completing the ground circuit at connector C1 terminal A11 of the EBCM. The magnetic field created closes the Electronic Brake Control Relay contacts. The magnetic field also allows battery voltage and current through the Electronic Brake Control Relay terminal C8 to be supplied to the EBCM through connector C2 terminal C and to the brake solenoid valves through S133.

Conditions for Setting the DTC

DTC C1217 can set before the EBCM commands the Electronic Brake Control Relay on.

DTC C1217 determines if the Electronic Brake Control Relay energizes when the Electronic Brake Control Relay should not energize. The above malfunction would not allow the Electronic Brake Control Relay to remove power to the ABS system.

If a second malfunction occurs, that requires the Electronic Brake Control Relay to turn off, the second malfunction cannot be removed if the Electronic Brake Control Relay cannot be controlled.

Action Taken When the DTC Sets

    • A malfunction DTC stores.
    • The ABS does not disable.

Conditions for Clearing the DTC

    • The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used.
    • 100 drive cycles pass with no DTCs detected.

Diagnostic Aids

The following conditions may cause an intermittent malfunction:

    • A poor connection
    • Rubbed-through wire insulation
    • A broken wire inside the insulation

Use the enhanced diagnostic function of the Scan Tool in order to measure the frequency of the malfunction. Refer to the Scan Tool manual or Scan Tool Diagnostics located in this section for the procedure.

Thoroughly inspect any circuitry that may be causing the intermittent complaint for the following conditions:

    • Backed out terminals
    • Improper mating
    • Improperly formed or damaged terminals
    • Poor terminal-to-wiring connections
    • Physical damage to the wiring harness

Clear the DTCs after completing the diagnosis.

Test drive the vehicle for three drive cycles in order to verify that the DTC does not reset.

Use the following procedure in order to complete one drive cycle:

  1. Start the vehicle.
  2. Drive the vehicle over 16 km/h (10 mph).
  3. Stop the vehicle.
  4. Turn the ignition to the OFF position.

Important: Zero the J 39200 test leads before making any resistance measurements.

Step

Action

Value(s)

Yes

No

1

Was the Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Turn the ignition switch to the OFF position.
  2. Install a scan tool.
  3. Turn the ignition switch to the ON position.
  4. Do not start the engine.

  5. Use the relay test function of the scan tool in order to view the Electronic Brake Control (ABS) Relay command.

Does the scan tool indicate that the Electronic Brake Control (ABS) Relay is off?

--

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the 24-way EBCM connector C1.
  3. Turn the ignition switch to the ON position.
  4. Do not start the engine.

  5. Use the J 39200 in order to measure the voltage between the 24-way EBCM connector C1 terminal A11 and the battery voltage.

Is the voltage equal to or greater than the specified voltage?

10 V

Go to Step 4

Go to Step  5

4

  1. Turn the ignition switch to the OFF position.
  2. Inspect the following components:
  3. • The 24-way EBCM connector C1 terminal A11
    • The remaining terminals of the 24-way EBCM connector C1
  4. Inspect the above components for the following conditions:
  5. • Damage
    • Poor terminal contact
    • Terminal corrosion

Are there signs of poor terminal contact, corrosion, or damaged terminals?

--

Go to Step 7

Go to Step 6

5

Use the J 39200 to measure the resistance between the 24-way EBCM connector C1 terminal A11 and ground.

Is the resistance within the specified range?

OL (Infinite)

Go to Step 6

Go to Step 8

6

  1. Reconnect the 24-way EBCM connector C1.
  2. Turn the ignition switch to the ON position.
  3. Do not start the engine.

  4. Use the scan tool in order to look for DTCs.

Does DTC C1217 set as a current DTC?

--

Go to Step 10

Go to Diagnostic Aids

7

Replace all of the terminals or connectors that exhibit signs of poor terminal contact, corrosion, or damaged terminals.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

8

Repair the short to ground in CKT 1632.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

9

Replace the Electronic Brake Control Relay. Refer to Electronic Brake Control Relay Replacement .

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

10

Replace the EBCM. Refer to Electronic Brake Control Module Replacement .

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--