GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The suspension control module performs internal checks on the software (calibrations) contained in the EEPROM to ensure valid operation.

Conditions for Running the DTC

Upon key on and reset.

Conditions for Setting the DTC

The suspension control module detects internal problems with software (calibrations).

Action Taken When the DTC Sets

    • Disable all functions, (EVO, Rear Leveling and RTD).
    • The SERVICE RIDE CONTROL message will be displayed.
    • DTC C0551 will be set.

Conditions for Clearing the MIL/DTC

The cause of the malfunction is not present upon the next key on cycle.

Using the scan tool.

Diagnostic Aids

Calibrate the suspension control module twice before replacement and cycle the ignition off and on to see if the DTC C0551 resets.

The replacement suspension control module must be calibrated when replacement is necessary.

Test Description

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

  1. Checks for other stored DTC's

  2. Checks to determine if DTC C0551 will re-set.

Step

Action

Value(s)

Yes

No

1

Did you perform the RTD Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check

2

  1. Connect a scan tool.
  2. Turn ON the ignition with the engine OFF.
  3. Select the Suspension Control Module display DTCs function on the scan tool.

Are there any other DTC's than C0551?

--

Go to Diagnostic Trouble Code (DTC) List/Type

Go to Step   3

3

Important: Perform the set up procedure (re-calibrate) for the suspension control module.

  1. Use the scan tool in order to clear the DTCs.
  2. Use the scan tool to re-calibrate the suspension control module. Refer to Electronic Suspension Control Module Replacement .
  3. Road test the vehicle.
  4. Select the Suspension Control Module display DTCs function on the scan tool.

Does the scan tool display DTC C0551?

--

Go to Step 4

Go to Diagnostic System Check

4

Important: Perform the set up procedure (re-calibrate) for the suspension control module after replacement.

Replace the suspension control module. Refer to Electronic Suspension Control Module Replacement .

Did you complete the replacement?

--

System OK

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