Pinpoint Test Y: The Air Conditioning Operation Is Erratic
Climate Control System
Pinpoint Test Y: The Air Conditioning Operation Is Erratic
Normal Operation
Under normal operation when the A/C system is on, the engine cooling fan operates as commanded ON or OFF by the PCM to cool down the A/C condenser core.
This pinpoint test is intended to diagnose the following:
- Engine cooling fan
PINPOINT TEST Y : THE AIR CONDITIONING OPERATION IS ERRATIC
Y1 CHECK THE ENGINE COOLING FAN (FAN_DSD) PCM PID OPERATION
- Ignition OFF.
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: FAN_DSD PCM PID.
- Command the PID 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?
Yes
REFER to Refrigerant System Tests Refrigerant System Tests, procedure to DIAGNOSE the A/C system. TEST the system for normal operation.
No
Install a new cooling fan Test the system for normal operation.