GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC 031: Exhaust Valve Circuit Short to Ground

DTC 032: Exhaust Valve Circuit Short to Battery or Open

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Exhaust Inflator Valve Control

031

032

032

--

Exhaust Inflator Valve B+

--

1

--

--

1. Exhaust Solenoid Valve Inoperative

Circuit/System Description

The automatic level control sensor monitors the exhaust valve control circuitry for a short to ground, short to battery, or an open/high resistance circuit.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

031

Short to ground in the control circuit of the exhaust valve

032

Open, or shorted to B+ in the control circuit of the exhaust valve

Action Taken When the DTC Sets

The automatic level control sensor disables leveling functions.

Conditions for Clearing the DTC

The conditions that caused the DTC to set have been removed.

Reference Information

Schematic Reference

Automatic Level Control Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Automatic Level Control Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Verify that automatic level control functions are disabled.

Circuit/System Testing

  1. Ignition OFF, disconnect the exhaust valve harness connector at the automatic level control sensor.
  2. Ignition ON, verify that a test lamp illuminates between the exhaust valve B+ circuit and ground.
  3. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the automatic level control sensor.
  4. Ignition ON, connect a test lamp between the exhaust valve control circuit and the B+ circuit of the exhaust valve. Command the exhaust valve ON and OFF.
  5. If the test lamp does not illuminate, test the control circuit for a short to ground or open. If the circuit tests normal, test or replace the automatic level control sensor.
    If the test lamp illuminates, test or replace the exhaust valve.
  6. If all circuits test normal, test or replace the automatic level control sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Important: System untested codes will continue to flash until self test has been completed after automatic level control sensor replacement.

    •  Control Module References for automatic level control sensor replacement, setup, and programming
    •  Air Compressor Replacement