GM Service Manual Online
For 1990-2009 cars only

Circuit Description

On the power-up self test, the calibration data stored in the electronically erasable programmable read-only memory (EEPROM) is copied to shadow RAM. Data checksums are generated and verified, and the data in shadow RAM is verified against the contents of the EEPROM. In certain situations data is written to the EEPROM. In these circumstanced any checksums are recalculated, and the data written to the EEPROM is read back and compared with the original data.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

If the EEPROM test fails then it is repeated. If the fault is still present after 5 test cycles, then a DTC is set.

Action Taken When the DTC Sets

    • Air Suspension functionality is suspended.
    • SERVICE AIR SUSPENSION message is displayed.

Conditions for Clearing the DTC

DTC is cleared by cycling ignition.

Step

Action

Yes

No

Schematic Reference: Suspension Controls Schematics

1

Did you perform the Air Suspension Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Air Suspension

2

Perform the suspension position calibration. Refer to Suspension Position Calibration .

Does the DTC reset?

Go to Step 3

System OK

3

Replace the electronic suspension control module. Refer to Automatic Level Control Air Compressor Replacement .

Did you complete the replacement.

System OK

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