GM Service Manual Online
For 1990-2009 cars only

Object Number: 244771  Size: MF

Circuit Description

Ignition voltage is supplied through terminal C10 of the Electronic Brake Control. The above condition enables the EBCM to energize the pullin 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 B10 to be supplied to the EBCM through connector C2 terminal C. Connector C2 terminal C supplies power to the motors and solenoids.

Conditions for Setting the DTC

DTC C1214 can set anytime after the EBCM commands the Electronic Brake Control Relay on. The command occurs during the three second bulb check.

DTC C1214 monitors the availability of current/voltage to the motors and solenoids.

The above malfunction indicates voltage is not available. The malfunction will not allow ABS operation.

Action Taken When the DTC Sets

    • A malfunction DTC stores.
    • The ABS disables.
    • The amber ABS warning indicator(s) turn on.
    • The red BRAKE warning indicator turns on if the rear piston in the ABS brake motor pack is not in the home position.

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 DTC(s) 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 for the procedure.

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

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

Vibration and Temperature Effects

    • Use the following procedure in order to inspect for vibration effects by performing the Relay Test function of the Scan Tool:
        1. With the Relay Test commanded on, lightly tap the top and sides of the Electronic Brake Control Relay while monitoring the Electronic Brake Control Relay voltage.
        2. If the Electronic Brake Control Relay voltage changes significantly, replace the Electronic Brake Control Relay.
    • If DTC C1214 only sets when the vehicle is initially started in cold ambient conditions (temperature less than 0°C - 32°F), replace the Electronic Brake Control Relay.

Important: Zero the J 39200 test leads before making any resistance measurements. Refer to the J 39200 user's manual.

Step

Action

Value(s)

Yes

No

1

Was the Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check

2

  1. Turn the ignition switch to the OFF position.
  2. Install a Scan Tool .
  3. Turn the ignition switch to the RUN position.
  4. Do not start the engine.

    Use the Scan Tool in order to read the DTCs.

Is DTC C1216 present (either as a current DTC or a history DTC)?

--

Go to DTC C1216 Brake Control Relay Coil Circuit Open

Go to Step 3

3

  1. Select Data List on the Scan Tool .
  2. Select and observe EBCM Battery Voltage.

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

10 V

Go to Step 25

Go to Step 4

4

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the 24-way EBCM connector C1.
  3. Connect a fused jumper wire (such as a J 36169-A ) with a 3A fuse between the 24-way EBCM harness connector C1 terminal A11 and ground.
  4. Turn the ignition switch to the RUN position.
  5. Do not start the engine.

  6. Use the J 39200 in order to measure the voltage between the 8-way EBCM harness connector C2 terminal C and ground.

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

10 V

Go to Step 5

Go to Step 10

5

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the fused wire jumper.
  3. Disconnect the Electronic Brake Control Relay.
  4. Use the J 39200 in order to measure the resistance between the Electronic Brake Control Relay harness connector terminal A2 and the EBCM harness connector C2 terminal C.

Is the resistance within the specified range?

0-2 ohms

Go to Step 6

Go to Step 19

6

  1. Disconnect the negative battery cable.
  2. Disconnect the positive battery cable.
  3. Use the J 39200 in order to measure the resistance between the positive battery cable terminal and the Electronic Brake Control Relay harness connector terminal B10.

Is the resistance within the specified range?

0-2 ohms

Go to Step 7

Go to Step 20

7

  1. Connect a jumper wire between the Electronic Brake Control Relay harness connector terminal C2 to the ground.
  2. Connect a fused jumper wire (such as a J 36169-A ) with a 3A fuse between the Electronic Brake Control Relay terminal B8 and the battery voltage.
  3. Use the J 39200 in order to measure the resistance between the Electronic Brake Control Relay terminal C8 and terminal B10.

Is the resistance within the specified range?

0-2 ohms

Go to Step 8

Go to Step 22

8

  1. Turn the ignition switch to the OFF position.
  2. Inspect the following components:
  3. • The 24-way EBCM connector C1
    • The 8-way EBCM connector C2
    • The 24-way EBCM harness connector C1
    • The 8-way EBCM harness connector C2
    • The Electronic Brake Control Relay
    • The Electronic Brake Control Relay harness connector
  4. Inspect the above components for signs of the following conditions:
  5. • Damage
    • Poor terminal contact
    • Terminal corrosion
  6. Inspect the following components:
  7. • The positive battery terminal
    • The positive battery cable terminal
    • The negative battery terminal
    • The negative battery cable terminal
  8. Inspect the above components for signs of the following conditions:
  9. • A poor connection
    • A poor terminal contact
    • Refer to Troubleshooting Procedures, in Electrical Diagnosis.

Are there signs of poor terminal contact, corrosion, or damaged terminal(s)?

--

Go to Step 17

Go to Step 9

9

  1. Remove all of the jumpers.
  2. Reconnect the EBCM connector C1 and connector C2.
  3. Reconnect the Electronic Brake Control Relay
  4. Reconnect the positive battery cable.
  5. Reconnect the negative battery cable.
  6. Turn the ignition switch to the RUN position.
  7. Do not start the engine.

  8. Use the Scan Tool in order to look for current DTCs.

Does DTC C1214 set as a current DTC?

--

Go to Step 24

Go to Step 25

10

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the negative battery cable.
  3. Disconnect the positive battery cable.
  4. Turn the ignition switch to the RUN position.
  5. (This action completes the ignition circuit to the Electronic Brake Control Relay.)

  6. Use the J 39200 in order to measure the resistance between the 24-way EBCM harness connector C1 terminal A11 and the positive battery cable terminal.

Is the resistance within the specified range?

0-95 ohms

Go to Step 11

Go to Step 14

11

Use the J 39200 in order to measure the voltage between the positive battery terminal and the negative battery terminal.

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

10 V

Go to Step 12

Go to Step 23

12

  1. Turn the ignition switch to the OFF position.
  2. Reconnect the positive battery cable.
  3. Reconnect the negative battery cable.
  4. Disconnect the Electronic Brake Control Relay.
  5. Use the J 39200 in order to measure the voltage between the Electronic Brake Control Relay harness connector terminal C1 and ground.

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

10 V

Go to Step 13

Go to Step 20

13

Use the J 39200 in order to measure the voltage between the Electronic Brake Control Relay harness connector terminal C8 and the 8-way EBCM harness connector C2 terminal C.

Is the resistance within the specified range?

0-2 ohms

Go to Step 7

Go to Step 19

14

  1. Disconnect the Electronic Brake Control Relay.
  2. Use the J 39200 in order to measure the resistance between the Electronic Brake Control Relay terminal 85 and the Electronic Brake Control Relay terminal 86.

Is the resistance within the specified range?

0-95 ohms

Go to Step 15

Go to Step 22

15

Use the J 39200 in order to measure the resistance between the Electronic Brake Control Relay harness connector terminal B8 and the 8-way EBCM harness connector C1 terminal A11.

Is the resistance within the specified range?

0-2 ohms

Go to Step 16

Go to Step 18

16

Use the J 39200 in order to measure the resistance between the Electronic Brake Control Relay harness connector terminal C10 and the positive battery cable terminal.

Is the resistance within the specified range?

0-2 ohms

Go to Step 8

Go to Step 21

17

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

Is the repair complete?

--

Go to Diagnostic System Check

--

18

Repair the open or high resistance in CKT 1632. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

19

Repair the open or high resistance in CKT 1633. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

20

Repair the open or high resistance in CKT 542. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

21

Repair the open or high resistance in the following components as necessary:

    • CKT 341
    • CKT 300
    • The ignition switch
    • The battery feed to the ignition switch

Is the repair complete?

--

Go to Diagnostic System Check

--

22

Replace the Electronic Brake Control Relay.

Is the repair complete?

--

Go to Diagnostic System Check

--

23

Repair the low voltage condition.

Is the repair complete?

--

Go to Diagnostic System Check

--

24

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

Is the repair complete?

--

Go to Diagnostic System Check

--

25

The malfunction is intermittent or is not present at this time.

Is the action complete?

--

Go to Diagnostic Aids

--