GM Service Manual Online
For 1990-2009 cars only

Object Number: 234333  Size: MF
ABS Components
Cell 44: DLC and Solenoids
Handling ESD Sensitive Parts Notice

Circuit Description

This DTC identifies a solenoid that cannot be energized due to an open in its circuitry, or a solenoid that is always energized due to a short to ground in its circuitry between the EBCM and the solenoid.

An open will not allow proper ABS operation, but the short to ground simply turns ON the solenoid. A path for base brakes is still allowed once the motor rehomes and the check valve is lifted off its seat when the ignition switch is turned to ON.

Conditions for Setting the DTC

DTC C1276 can set only when the brake solenoid valve is commanded off while the Electronic Brake Control Relay is enabled.

A malfunction exists if the EBCM detects the left front brake solenoid valve control circuit voltage is not within specifications.

Action Taken When the DTC Sets

    • A malfunction DTC stores.
    • The ABS disables.
    • The ABS warning indicator turns ON.

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. A drive cycle consists of starting the vehicle, driving the vehicle over 16 km/h (10 mph), stopping and then turning the ignition OFF.

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.

Thoroughly inspect any circuitry that may cause 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

Test Description

  1. This test checks for a short to ground in the left front solenoid valve circuit.

  2. This test checks for an open in the control circuit of the solenoid.

  3. This test checks for a short to ground in the control circuit of the solenoid.

  4. This test checks for an open in the battery feed circuit to the solenoid.

  5. This test checks for an open in the left front solenoid valve.

  6. This test determines if the malfunction is caused by the EBCM.

Step

Action

Value(s)

Yes

No

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

1

Was the A Diagnostic System Check-ABS performed?

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Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Turn the ignition switch to LOCK.
  2. Disconnect the EBCM connector C1.
  3. Use the J 39200 in order to measure the resistance between the EBCM harness connector C1 terminal A10 and ground.

Is the resistance within the specified range?

OL

(Infinite)

Go to Step 3

Go to Step 4

3

  1. Disconnect the left front brake solenoid valve connector.
  2. Use the J 39200 in order to measure the resistance between the EBCM harness connector  C1 terminal A10 and the left front brake solenoid valve harness connector terminal B.

Is the resistance within the specified range?

0-2 ohms

Go to Step 5

Go to Step 9

4

  1. Disconnect the LF ABS solenoid connector.
  2. Use the J 39200 in order to measure the resistance between the left front ABS brake solenoid valve connector terminal B and ground.

Is the resistance within the specified range?

OL

(Infinite)

Go to Step 8

Go to Step 11

5

  1. Disconnect the EBCM harness connector C2.
  2. Use the J 39200 in order to measure the resistance between the EBCM harness connector C2 terminal C and the left front ABS solenoid valve harness connector terminal A.

Is the resistance within the specified range?

0-2 ohms

Go to Step 6

Go to Step 10

6

Use the J 39200 in order to measure the resistance between the LF ABS solenoid terminals A and B.

Is the resistance within the specified range?

2.5-5.0 ohms

Go to Step 7

Go to Step 11

7

  1. Inspect the LF ABS solenoid and connectors for poor terminal contact or corrosion.
  2. Inspect the WHT and BLU/WHT wires between the EBCM and the LF ABS solenoid for damage which may result in a short to ground with all connectors connected.
  3. Reconnect all connectors.
  4. Start the engine.
  5. Drive the vehicle at 16 km/h (10 mph) for 10 seconds.
  6. Stop the vehicle and turn the ignition switch to LOCK.
  7. Repeat the drive cycle (steps 4, 5 and 6).
  8. Turn the ignition switch to ON.
  9. Using the scan tool, check for DTCs.

Did DTC C1276 set in the past three ignition cycles?

--

Go to Step 12

Go to Diagnostic System Check - ABS

8

Repair the short to ground in the BLU/WHT wire between the EBCM and the LF ABS solenoid. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 6

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9

Repair the open or high resistance in the BLU/WHT wire between the EBCM and the LF ABS solenoid. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

10

Repair the open or high resistance in the WHT wire between the EBCM and the LF ABS solenoid. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

11

Replace the LF ABS solenoid. Refer to Brake Solenoid Valve Replacement .

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

12

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

Is the replacement complete?

--

Go to Diagnostic System Check - ABS

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