GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1999 🢒 Eldorado 🢒 Suspension 🢒 Road Sensing Suspension (RSS) 🢒 DTC C1658 RSS Control Module Calibration Fault

Circuit Description

The CVRSS control module performs checks of internal calibration data. If a fault condition is detected, the CVRSS control module will set the fault DTC, and may, depending upon the fault type, turn on the SERVICE RIDE CONTROL message. Additionally, depending upon the type of the internal fault, the system will either enter a Speed Dependent Damping mode or disable all dampers. In the latter case, a message will be sent to the PCM to cause the vehicle speed to be limited. Recovery from any controller fault condition is attempted only after the ignition is cycled ON and OFF.

Conditions for Setting the DTC

The DTC is set when any calibration faults, internal to the CVRSS controller, are detected.

The DTC turns HISTORY when the CVRSS control module no longer senses the hardware fault and the ignition is cycled OFF and ON.

Action Taken When the DTC Sets

Depending upon which of the internal functions are affected by the fault condition, the CVRSS control module will take one of two sets of actions:

    • If the fault condition allows continued output operation, the system will enter a Speed Dependent Damping mode, in which all four corners of the vehicle are concurrently driven by a fixed PWM duty cycle, which increases as a function of the vehicle speed. The SERVICE RIDE CONTROL will be displayed.
    • If the fault is more severe, the control module will disable ALL dampers by commanding 0 % PWM duty cycle, disabling the damper switched battery circuit, and sending a message to the Powertrain Control Module (PCM) to limit vehicle speed. The SERVICE RIDE CONTROL will be displayed.

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 checks to see if the problem has cleared after the CVRSS control module has been calibrated.

    2.

  2. This step checks to see if the problem has cleared after the CVRSS control module has been calibrated.

Step

Action

Value(s)

Yes

No

1

Was the CVRSS System Check performed?

--

Go to Step 2

Go to Road Sensing Suspension Diagnostic System Check

2

  1. Install the scan tool.
  2. Turn the ignition ON with the engine off.
  3. Calibrate the CVRSS control module using the scan tool. Refer to Electronic Suspension Control Module Calibration .
  4. Clear the DTCs. Refer to Clearing DTCs .
  5. Wait 30 seconds and then check the CVRSS DTCs. Refer to Displaying Diagnostic Trouble Codes (DTC) .

Is DTC C1658 set?

--

Go to Step 3

Go to Road Sensing Suspension Diagnostic System Check

3

  1. Calibrate the CVRSS control module using the scan tool. Refer to Electronic Suspension Control Module Calibration .
  2. Clear the DTCs. Refer to Clearing DTCs .
  3. Wait 30 seconds and then check the CVRSS DTCs. Refer to Displaying Diagnostic Trouble Codes (DTC) .

Is DTC C1658 set?

--

Go to Step 4

Go to Road Sensing Suspension Diagnostic System Check

4
  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.

  6. 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

--