2010 Cadillac CTS Sedan AWD V6-3.0L Page 1554

2010 Cadillac CTS Sedan AWD V6-3.0L Page 1554

- Air Conditioning (A/C) Clutch Relay Control Circuit High Voltage

Diagnostic Fault Information

Circuit/System Description

When the A/C switch is pressed, the HVAC control assembly sends a serial data message to the engine control module (ECM) for an A/C request.

This input will request the ECM to ground the A/C compressor clutch relay control circuit, which will switch the A/C CLTCH relay. With the relay

contacts closed, battery voltage is supplied to the A/C compressor clutch assembly.

Conditions for Running the DTC

* The ignition voltage is between 9 and 18 volts.

* The engine speed is more than 600 RPM.

* An A/C request is made.

Conditions for Setting the DTC

* A short to ground on the A/C compressor clutch relay control circuit.

* A short to voltage on the A/C compressor clutch relay control circuit.

* An open circuit on the A/C compressor clutch relay control circuit or relay.

* An internally shorted or excessively low resistance A/C clutch relay coil.

Action Taken When the DTC Sets

* The A/C clutch relay is commanded OFF.

* The conditions for which the DTC was set will be stored in the Failure Records data only. No information will be stored as Freeze Frame

data.

Conditions for Clearing the DTC

The history DTC will clear after 40 fault-free ignition cycles.

Reference Information

Schematic Reference

HVAC Schematics (See: Heating and Air Conditioning/Diagrams/Electrical Diagrams)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views)

Description and Operation

Automatic HVAC Description and Operation (See: Heating and Air Conditioning/Description and Operation/HVAC - Automatic)

Electrical Information Reference

* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit

Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the A/C relay.