SUT

DTC B2795 (SUT)

Diagnostic Instructions

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



DTC Descriptor
DTC B2795 02
- Suspension Control Select Switch Circuit Short to Ground




Diagnostic Fault Information






Circuit Description

The air suspension module monitors the ride height switch signal for a short to ground or battery with ignition ON and up to 3 minutes with the ignition OFF.


Conditions for Running the DTC

* Battery voltage is between 9-16 volts.
* The ignition is ON or OFF.



Conditions for Setting the DTC

The air suspension module senses ride height switch signal circuit voltage shorted to ground or battery.


Action Taken When the DTC Sets

* The air suspension system will be inoperative.
* No message is displayed.



Conditions for Clearing the MIL/DTC

The DTC will clear when the condition for setting the DTC is removed.


Reference Information
Schematic Reference

Air Suspension Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Component Connector End Views)
Description and Operation

Air Suspension Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Programming and Relearning (Programming and Relearning) for Scan Tool Information


Circuit Validation

Ignition ON, Observe the scan tool ERH Switch parameter while pressing/depressing the ERH Switch. The reading should change between Released and Pressed.


Circuit/System Testing

1. Ignition OFF, disconnect the ERH switch harness connector terminal A1 at the automatic suspension control module (ASCM).
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit and ground.

• 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 and the B+ circuit fuse is open, test the signal circuit for a short to ground.

3. Verify the scan tool ERH Switch parameter is Released.

• If not the specified value, test the signal circuit terminal C for a short to voltage. If the circuit tests normal, test or replace the air suspension control module (ASCM).

4. Install a 3A fused jumper wire between the signal circuit terminal C and the Instrument Panel B+ circuit terminal. Verify the scan tool ERH Switch parameter is Pressed.

• If not the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the ASCM.


• If greater that the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ASCM.

5. If all circuits test normal, test or replace the ERH Switch (Rear Air Suspension Control Valve Switch).



Component Testing

1. Igniting OFF, disconnect the harness at the ERH switch (Rear Air Suspension Control Valve Switch).
2. Test for infinite resistance between the signal circuit terminal C and the B+ circuit terminal with the switch in the open position. (Released)

• If not the specified value, replace the switch.

3. Test for less than 2 ohms between the signal circuit terminal C and the B+ circuit terminal with the switch in the closed position. (Pressed)

• If greater than the specified range, replace the Rear Air Suspension Control Valve Switch.

4. Test for infinite resistance between each terminal and the Rear Air Suspension Control Valve Switch housing/case.

• If not the specified value, replace the ERH switch (Rear Air Suspension Control Valve Switch).




Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Rear Air Suspension Control Valve Switch Replacement (Rear Air Suspension Control Valve Switch Replacement)
* Suspension Position Calibration (Suspension Position Calibration)
* Programming and Relearning (Programming and Relearning) for Air Suspension Control Module replacement, setup and programming