Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while performing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, check to make sure connectors, terminals and wiring harnesses are connected correctly and undamaged.
When checking intake motor drive signal, test it within 20 seconds after switching REC/FRESH mode. For that signal turns off after 20 seconds.

NO. 4 AIR INTAKE MODE DOES NOT CHANGE DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1*	INSPECT TO SEE WHETHER MALFUNCTION (LACK OF CONTINUITY) IS IN AIR INTAKE ACTUATOR, WIRING HARNESS (BETWEEN CLIMATE CONTROL UNIT AND AIR INTAKE ACTUATOR) OR ELSEWHERE Turn ignition switch to ON position. Test voltages at the following terminals of climate control unit: Terminal 2K (FRESH motor drive signal) Terminal 2I (RECIRCULATE motor drive signal) (See FULL-AUTO AIR CONDITIONER ) Are voltages okay?	Yes	Go to next step.
1*		No	Go to Step 3.
2*	INSPECT TO SEE WHETHER MALFUNCTION (LACK OF CONTINUITY) IS IN AIR INTAKE ACTUATOR OR WIRING HARNESS (BETWEEN CLIMATE CONTROL UNIT AND AIR INTAKE ACTUATOR) Test voltages at the following terminals of air intake actuator: Terminal H (FRESH motor drive signal) Terminal G (RECIRCULATE motor drive signal) Are voltages as shown below? Terminal H: approximately 0.5 V during RECIRCULATE and approximately 10 V during FRESH Terminal G: approximately 10 V during RECIRCULATE and approximately 0.5 V during FRESH	Yes	Replace air intake actuator, then go to Step 8.
2*		No	Repair wiring harness between climate control unit and air intake actuator, then go to Step 8.
3	INSPECT TO SEE WHETHER MALFUNCTION IS IN AIR INTAKE ACTUATOR OR ELSEWHERE Disconnect air intake actuator connector. Test voltages at the following terminals of climate control unit: Terminal 2K (FRESH motor drive signal) Terminal 2I (RECIRCULATE motor drive signal) (See FULL-AUTO AIR CONDITIONER ) Are voltages okay?	Yes	Inspect air intake actuator, then go to Step 8.
3		No	Go to next step.
4	INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (SHORT TO B+ BETWEEN CLIMATE CONTROL UNIT AND AIR INTAKE ACTUATOR) OR ELSEWHERE Disconnect climate control unit connector. Test voltages at the following terminals of climate control unit: Terminal 2K (FRESH motor drive signal) Terminal 2I (RECIRCULATE motor drive signal) Are voltages approximately 0 V?	Yes	Go to next step.
4		No	Repair wiring harness between climate control unit and air intake actuator, then go to Step 8.
5	INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (SHORT TO GROUND BETWEEN CLIMATE CONTROL UNIT AND AIR INTAKE ACTUATOR) OR ELSEWHERE Turn ignition switch to LOCK position. Inspect for continuity at the following terminals between climate control unit and ground: Terminal 2K (FRESH motor drive signal) Terminal 2I (RECIRCULATE motor drive signal) Is there continuity?	Yes	Repair wiring harness between climate control unit and air intake actuator, then go to Step 8.
5		No	Go to next step.
6	INSPECT AIR INTAKE LINK Inspect air intake links. Is there grease on link? Are links securely and properly installed? Are links free of obstructions and hindrances? Are above items okay?	Yes	Go to next step.
6		No	Apply grease to links. If any links are damaged, replace air intake actuator, then go to Step 8.
7	INSPECT TO SEE WHETHER MALFUNCTION IS IN CLIMATE CONTROL UNIT OR AIR INTAKE DOOR Inspect blower unit air intake door. Is door free of obstructions, cracks, and damage? Are doors securely and properly installed? Are above items okay?	Yes	Replace climate control unit, then go to next step.
7		No	Remove obstruction, or install doors in proper positions. If any doors are cracked or damaged, replace them, then go to next step.
8	CONFIRM THAT MALFUNCTION SYMPTOMS DO NOT RECUR AFTER REPAIR Does air intake mode change smoothly?	Yes	Troubleshooting completed. Explain repairs to customer.
8		No	Recheck malfunction symptoms, then repeat from Step 1 if malfunction recurs.