GM Service Manual Online
For 1990-2009 cars only

Circuit Description


Object Number: 258351  Size: SF

The CVRSS module estimates the road surface and communicates that information to the Electronic Brake and Traction Control Module (EBTCM) using the ICCS2 Datalink Left and Right Outputs. The EBTCM uses this information to provide improved rough-road braking performance.

Conditions for Setting the DTC

The DTC is set when the CVRSS module measures a feedback voltage less than a preset threshold during an ICCS2 Datalink Left Output OFF state.

The DTC turns HISTORY when the CVRSS module no longer senses a low feedback voltage during five (5) consecutive ICCS2 Datalink Left Output OFF states.

Action Taken When the DTC Sets

    • Both of the ICCS2 Datalink Outputs are set to default output states.
    • The SERVICE RIDE CONTROL message will be displayed.

Conditions for Clearing the MIL/DTC

    • Use the scan tool.
    • Use the On-Board diagnostic CLEAR RSS CODES feature.

Test Description

Important: 

   • Do not backprobe the sensors, actuators, or any sealed connectors.
   • When all the diagnostics and repairs are complete, clear the DTCs and verify the operation.

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

  1. This step determines if the fault is due to a short circuit to ground condition or an open circuit condition in CKT 790 and determines if the short circuit to ground condition is in the wiring or with the EBTCM.

  2. This step checks for an open circuit condition in CKT 790.

  3. This step checks for a short circuit to ground condition in CKT 790.

Step

Action

Value(s)

Yes

No

1

Was the Road Sensing Suspension Diagnostic System Check performed?

--

Go to Step 2

Go to Road Sensing Suspension Diagnostic System Check

2

  1. Turn the ignition OFF.
  2. Disconnect CVRSS control module connector C1.
  3. Turn the ignition ON with the engine off.
  4. Measure the voltage between CVRSS control module connector C1, terminal D15 (harness side), and ground with a J 39200 DMM.

Is the voltage greater than the specified value?

10 V

Go to Step 7

Go to Step 3

3

  1. Turn the ignition OFF.
  2. Disconnect EBTCM connector C2.
  3. Measure the resistance between CVRSS module connector C1, terminal D15, and EBTCM connector C2, terminal 18, with a DMM.

Is the resistance equal to or less than the specified value?

5 ohms

Go to Step 4

Go to Step 5

4

Measure the resistance between CVRSS module connector C1, terminal D15, and ground with a DMM.

Is the resistance the specified value?

OL

Go to Step 8

Go to Step 6

5

Repair the open circuit condition or poor connection condition in CKT 790.

Is the repair complete?

--

Go to Road Sensing Suspension Diagnostic System Check

--

6

Repair the short circuit to ground condition in CKT 790.

Is the repair complete?

--

Go to Road Sensing Suspension Diagnostic System Check

--

7

  1. Turn the ignition OFF.
  2. Replace the CVRSS control module. Refer to Electronic Suspension Control Module Replacement .
  3. Install all of the connectors and components that were removed.
  4. Install the scan tool.
  5. Turn the ignition ON with the engine off.
  6. Important: The controller must be calibrated.

  7. Calibrate the CVRSS service controller using the scan tool. Refer to Electronic Suspension Control Module Calibration .

Is the CVRSS control module calibrated?

--

Go to Road Sensing Suspension Diagnostic System Check

--

8

  1. Turn the ignition OFF.
  2. Replace the EBTCM. Refer to Electronic Brake Control Module Replacement .

Is the repair complete?

--

Go to Road Sensing Suspension Diagnostic System Check

--