GM Service Manual Online
For 1990-2009 cars only

Object Number: 598281  Size: MF
ABS Components
Precision Control System (PCS) (RPO JL4)

Circuit Description

The EBCM monitors the received messages from the steering angle sensor for corruption or for missing messages.

Conditions for Running the DTC

    • The ignition is ON.
    • The vehicle speed is greater than 40 km/h (25 mph).

Conditions for Setting the DTC

The EBCM receives a corrupt or a missing message after 100 milliseconds.

Action Taken When the DTC Sets

    • A malfunction DTC is set
    • TCS and VSES are disabled
    • TCS, SERVICE VEHICLE SOON and PCS lamp indicators turn on

Conditions for Clearing the DTC

    • The condition for the DTC is no longer present.
    • Using a scan tool.
    • The EBCM automatically clears the history DTC when a current DTC is not detected in 124 consecutive drive cycles.

Diagnostic Aids

Possible causes of this DTC are as follows:

    • An open in the CAN HI or CAN LO circuit.
    • An open in the ignition circuit.
    • An open in the ground circuit.
    • Malfunctioning steering angle sensor.
    • Malfunctioning EBCM.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. Tests the ignition circuit for an open.

  2. Checks the ground circuit for an open.

  3. Tests the CAN HI circuit for an open.

  4. Tests the CAN LO circuit for an open.

  5. Checks the steering angle sensor connector for poor connections.

Step

Action

Value(s)

Yes

No

1

Did you perform the ABS Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Turn OFF the ignition.
  2. Disconnect the steering angle sensor harness connector.
  3. Using a DMM, check the ignition circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 3

3

  1. Disconnect the EBCM harness connector.
  2. Install the J 39700 universal pinout box with the J 39700-530 cable adapter between the EBCM and the EBCM harness connector.
  3. Disconnect the steering angle sensor.
  4. Using a DMM, check the ground circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 4

4

Using a DMM, check the CAN HI circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 5

5

Using a DMM, check the CAN LO circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 6

6

Inspect for poor connections at the harness connector of the steering angle sensor.

Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 7

7

Inspect for poor connections at the harness connector of the EBCM.

Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 8

8

Perform the steering angle sensor centering procedure. Refer to Steering Angle Sensor Centering .

Did you successfully complete the centering procedure?

--

Go to Step 9

Go to Step 10

9

  1. Use the scan tool in order to clear the DTCs.
  2. Test drive the vehicle. Refer to Diagnostic Test Drive .

Did DTC C1651 reset?

--

Go to Step 11

Go to Step 12

10

Replace the steering angle sensor. Refer to Steering Shaft, Lower Bearing, and Jacket - Disassemble - Off Vehicle in Steering Wheel and Column - Tilt.

Did you complete the replacement?

--

Go to Step 12

--

11

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

Did you complete the replacement?

--

Go to Step 12

--

12

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting test.

Does the DTC reset?

--

Go to Step 2

System OK