GM Service Manual Online
For 1990-2009 cars only

Object Number: 106509  Size: MF
ABS Components
Cell 44: Lateral Accelerometer, Yaw Rate, and Steering Wheel Position Sensors
Handling ESD Sensitive Parts Notice

Circuit Description

When Stabilitrak® or TCS activates for longer than 1.5 seconds, there will be an accompanying DIC message. Short activations of either system may occur without any DIC messages. Stabilitrak® activations mostly occur in the turns or bumpy roads without much use of the accelerator pedal. Activations may also occur during aggressive driving. Unwanted Stabilitrak® activations may be caused by the following:

    • A loosely mounted yaw rate sensor
    • An intermittent faulty steering wheel position sensor
    • An intermittent wiring harness problem
    • A chassis alignment that is grossly out of specification
    • The wrong EBTCM installed
    • The wrong steering gear rack installed

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

Check the mounting of the yaw rate sensor.

Is the yaw rate sensor properly secured?

--

Go to Step 4

Go to Step 3

3

Remount or properly secure the yaw rate sensor. Refer to Vehicle Yaw Sensor Replacement .

Has the repair been complete?

--

Go to Diagnostic System Check - ABS

--

4

  1. Turn OFF the ignition.
  2. Connect a scan tool to the data link connector (DLC).
  3. Turn the ignition switch to the ON position (start the engine).
  4. Use the scan tool in order to take a snapshot of the yaw rate sensor output.
  5. Test drive the vehicle and note the unwanted Stabilitrak® activations.

Does the yaw rate sensor output suddenly increase or decrease without rapid turning of the vehicle?

--

Go to DTC C1282 Yaw Rate Sensor Bias Circuit Malfunction

Go to Step 5

5

  1. Ensure that the front wheels are straight.
  2. Turn OFF the ignition.
  3. Turn the ignition switch to the ON position (start the engine).
  4. Use the scan tool in order to monitor the Digital SWPS Phase A and Digital SWPS Phase B in the ABS/TCS/ICCS Data Display (1) Diagnostics, DATA LIST 2.
  5. Slowly rotate the steering wheel to the left.

Did Phase A and Phase B change states as the steering wheel was rotated?

--

Go to Step 6

Go to Step 8

6

  1. Continue monitoring the Digital SWPS Phase A and Digital SWPS Phase B in the ABS/TCS/ICCS Data Display (1) Diagnostics, DATA LIST 2.
  2. Slowly rotate the steering wheel to the right.

Did Phase A and Phase B change states as the steering wheel was rotated?

--

Go to Step 7

Go to Step 8

7

Perform the Steering Position Sensor Test. Refer to Scan Tool Diagnostics .

Was the Steering Position Sensor Test passed?

--

Go to Step 9

Go to Step 8

8

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

Has the replacement been completed?

--

Go to Diagnostic System Check - ABS

--

9

  1. Place the vehicle on a level surface.
  2. Use the scan tool in order to display the Lateral Accelerometer Input in the ABS/TCS/ICCS Data Display (1) Diagnostics, DATA LIST 2.

Is the Lateral Accelerometer Input voltage within the specified range?

2.3-2.7 V

Go to Step 14

Go to Step 10

10

Check the mounting of the lateral accelerometer.

Is the lateral accelerometer properly secured?

--

Go to Step 12

Go to Step 11

11

Remount or properly secure the lateral accelerometer. Refer to Lateral Accelerometer Replacement .

Has the repair been completed?

--

Go to Step 12

--

12

Use the scan tool in order to display the Lateral Accelerometer Input in the ABS/TCS/ICCS Data Display (1) Diagnostics, DATA LIST 2.

Is the Lateral Accelerometer Input voltage within the specified range?

2.3-2.7 V

Go to Step 14

Go to Step 13

13

Replace the lateral accelerometer. Refer to Lateral Accelerometer Replacement .

Has the replacement been completed?

--

Go to Diagnostic System Check - ABS

--

14

Check the EBTCM for the proper part number.

Is the EBTCM part number correct?

--

Go to Step 15

Go to Step 17

15

Check the power steering gear for the proper part number.

Is the power steering gear part number correct?

--

Go to Step 16

Go to Step 18

16

  1. Perform the Diagnostic Test Drive. Refer to Diagnostic Test Drive .
  2. Check for obvious vehicle alignment problems.

Is the vehicle alignment proper?

--

Go to Diagnostic System Check - ABS

Go to Preliminary Alignment Inspection in Wheel Alignment

17

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

Is the replacement complete?

--

Go to Diagnostic System Check - ABS

--

18

Replace the power steering gear. Refer to Steering Gear Replacement in Power Steering System.

Is the replacement complete?

--

Go to Diagnostic System Check - ABS

--