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Diagnostic Routine Y




Diagnostic Routine Y

Diagnostic Overview

The Air Conditioning Operation Is Erratic

Refer to Wiring Diagram Set 33 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

Under normal operation when the A/C (Air Conditioning) system is on, the engine cooling fan operates as commanded On or OFF by the PCM (Powertrain Control Module) to cool down the A/C (Air Conditioning) condenser core.

Pinpoint Test

1. CHECK THE ENGINE COOLING FAN (FAN_DSD) PCM (Powertrain Control Module) PID (Parameter Identification) OPERATION

1. Ignition ON.

2. Using a scan tool, view PCM (Powertrain Control Module) PIDs (Parameter Identifications).

3. Monitor the PCM (Powertrain Control Module) PID (Parameter Identification) FAN_DSD.

4. Command the to drive the cooling fan from 0 to 100% of performance and confirm the fan increases speed as the percentage of performance commanded is increased.

Does the fan speed increase as the commanded performance is increased?