GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The longitudinal accelerometer is used to determine straight-line acceleration. This information is used when calculating the desired traction control in AWD applications.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0192 All Wheel Drive (AWD)/Four Wheel Drive (4WD) Reference Accelerometer Circuit

This vehicle has DTCs which include DTC symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description.

Symptom Type

Symptom Type Descriptor

00

No Additional Information

1A

Bias Level Out of Range

Conditions for Running the DTC

    • The ignition switch is turned ON.
    • Ignition voltage is greater than 8 volts.

Conditions for Setting the DTC

C0192 00

The following conditions may cause DTC to occur:

    • The longitudinal accelerometer sensor signal voltage is below 0.18 volt or higher than 4.84 volts for 30 milliseconds.
    • When the ignition is ON, the longitudinal accelerometer sensor cannot pass the internal self-test.

C0192 1A

The longitudinal accelerometer sensor has self-calibrated the change in temperature. If the calibration variation is more than 0.5 g, set the DTC.

Action Taken When the DTC Sets

    • Traction control system (TCS) is degraded.
    • The TCS indicators turn ON.
    • The antilock brake system (ABS) remains functional.

Diagnostic Aids

Thoroughly inspect connections and wiring that may cause an intermittent malfunction. Refer to Testing for Electrical Intermittents, Wiring Repairs, and Connector Repairs.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Tests for the proper voltage output on the 5-volt reference circuit and the proper operation of the signal circuit.

  2. Tests for possible low 5-volt reference output or a problem with the signal circuit.

  3. This step tests for a short to voltage on the 5-volt reference circuit. If a short to voltage exists, other DTCs may be set for the vehicle stability system if equipped.

  4. Tests for a problem with the low reference circuit. If a short to voltage exists, other DTCs may be set for the vehicle stability system if equipped.

Step

Action

Values

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Turn OFF the ignition.
  2. Connect a 3-amp fused jumper wire between the longitudinal accelerometer 5-volt reference circuit and the longitudinal accelerometer signal circuit.
  3. Turn ON the ignition, with the engine OFF.
  4. With the scan tool, observe the longitudinal accelerometer parameter.

Does the scan tool indicate that the longitudinal accelerometer parameter is in between the specified voltage range?

4.5-5.5 V

Go to Step 8

Go to Step 3

3

With the 3-amp fused jumper wire still connected, does the scan tool indicate that the longitudinal accelerometer parameter is in below the specified voltage value?

4.5 V

Go to Step 5

Go to Step 4

4

Test the longitudinal accelerometer 5-volt reference circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 12

Go to Step 7

5

Test the longitudinal accelerometer 5-volt reference circuit for the following conditions:

    • An open
    • A short to ground
    • A high resistance

Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 12

Go to Step 6

6

Test the longitudinal accelerometer signal circuit for the following conditions:

    • An open
    • A short to ground
    • A high resistance

Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 12

Go to Step 11

7

Test the longitudinal accelerometer signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 12

Go to Step 11

8

Test the longitudinal accelerometer low reference circuit for the following conditions:

    • An open
    • A short to voltage
    • A high resistance

Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 12

Go to Step 9

9

Inspect for poor connections at the harness connector of the yaw rate and lateral accelerometer sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 12

Go to Step 10

10

Replace the yaw rate and lateral accelerometer sensor. Refer to Brake Pressure Modulator Valve Pressure Sensor Replacement .

Did you complete the replacement?

--

Go to Step 12

--

11

Replace the electronic brake control module (EBCM). Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 12

--

12

  1. Clear the DTCs using the scan tool.
  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