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412-04-25 Control Components 412-04-25 DIAGNOSIS AND TESTING (Continued) NOTE: Ensure that there are no restrictions to HVAC airflow or excessive heat pick-up in to HVAC air intake before replacement of HIM. NOTE: REFER to Section 412-02 SYMPTOM CHART BEFORE PROCEEDING Test Step Result / Action to Take L1 WDS FUNCTIONAL TEST - HVAC BLOWER FAN OPERATION Run engine and ensure vehicle battery is at normal charge state. Yes System OK Select Face / Floor outlet mode. No Select Recirc inlet mode. Go to L2 Select full cold. Set the HVAC blower fan speed to maximum using WDS scan tool Is the HVAC Blower fan operating at full speed? L2 VISUAL INSPECTION - HVAC BLOWER MOTOR POWER FUSE Check HVAC blower motor power supply fuse. Yes Replace the fuse Is the fuse blown? No Go to L3 L3 ELECTRICAL INSPECTION - HVAC BLOWER MOTOR POWER SUPPLY Using a voltmeter, check that battery power is available at the HVAC Yes blower motor 2way connector C-221 Pin 1 lead 118B. Go to L4 Is approx battery voltage present? No Repair wiring fault L4 VISUAL INSPECTION - HVAC BLOWER MOTOR Check HVAC blower motor current draw with a clamp type ammeter Yes attached on to the HVAC blower fan battery supply lead. Pin 1 of Replace HVAC blower motor. 2way connector C-221 lead 118B. No Is the reading greater than 25 Amps? Go to L5 L5 VISUAL INSPECTION - HVAC BLOWER MOTOR Remove HVAC blower and inspect for lose or damaged impeller. Yes Replace HVAC blower motor. Is impeller damaged or lose fit on motor shaft? No Go to L6 L6 WDS FUNCTIONAL TEST - HVAC BLOWER FAN OPERATION Reinstall the HVAC blower fan motor and operate at mid and full Yes speeds for 10 minutes each using WDS scan tool with PID Go to L7 “BLOWTP”. No NOTE: More time may be required to run the blower at each speed System OK during low ambient temperature conditions (cold weather). Does the blower stop operating? A12342 en |