NO.4 AIR INTAKE MODE DOES NOT CHANGE


BHE070301038W06

4

Air intake mode does not change.

DESCRIPTION

• Air intake mode does not change when switching REC/FRESH mode.

POSSIBLE CAUSE

• Malfunction in air intake actuator (Steps 1-6)
• Malfunction in air intake door (Step 7)

• 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.

Diagnostic procedure

STEP

INSPECTION

ACTION

1*

INSPECT TO SEE WHETHER MALFUNCTION (LACK OF CONTINUITY) IS IN AIR INTAKE ACTUATOR, WIRING HARNESS (BETWEEN A/C AMPLIFIER AND AIR INTAKE ACTUATOR) OR ELSEWHERE

• Turn ignition switch to ON position.
• Test voltages at the following terminals of A/C amplifier:
– Terminal 1I (24-pin, FRESH motor drive signal)
– Terminal 1J (24-pin, RECIRCULATE motor drive signal)
(See A/C AMPLIFIER INSPECTION [FULL-AUTO AIR CONDITIONER].)
• Are voltages normal?
Yes
Go to next step.
No
Go to Step 3.
2*

INSPECT TO SEE WHETHER MALFUNCTION (LACK OF CONTINUITY) IS IN AIR INTAKE ACTUATOR OR WIRING HARNESS (BETWEEN A/C AMPLIFIER AND AIR INTAKE ACTUATOR)

• Test voltages at the following terminals of air intake actuator:
– Terminal A (FRESH motor drive signal)
– Terminal C (RECIRCULATE motor drive signal)
• Are voltages as shown below?
– Terminal A: approx. 0.5 V during RECIRCULATE and approx. 10 V during FRESH
– Terminal C: approx. 10 V during RECIRCULATE and approx. 0.5 V during FRESH
Yes
Replace air intake actuator, then go to Step 8. (See AIR INTAKE ACTUATOR REMOVAL/INSTALLATION.)
No
Repair wiring harness between A/C amplifier 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 A/C amplifier:
– Terminal 1I (24-pin, FRESH motor drive signal)
– Terminal 1J (24-pin, RECIRCULATE motor drive signal)
(See A/C AMPLIFIER INSPECTION [FULL-AUTO AIR CONDITIONER])
• Are voltages normal?
Yes
Inspect air intake actuator, then go to Step 8. (See AIR INTAKE ACTUATOR INSPECTION.)
No
Go to next step.
4

INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (SHORT TO B+ BETWEEN A/C AMPLIFIER AND AIR INTAKE ACTUATOR) OR ELSEWHERE

• Disconnect A/C amplifier connector.
• Test voltages at the following terminals of A/C amplifier:
– Terminal 1I (24-pin, FRESH motor drive signal)
– Terminal 1J (24-pin, RECIRCULATE motor drive signal)
• Are voltages approx. 0 V?
Yes
Go to next step.
No
Repair wiring harness between A/C amplifier and air intake actuator, then go to Step 8.
5

INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (SHORT TO GROUND BETWEEN A/C AMPLIFIER AND AIR INTAKE ACTUATOR) OR ELSEWHERE

• Turn ignition switch to LOCK position.
• Inspect for continuity at the following terminals between A/C amplifier and ground:
– Terminal 1I (24-pin, FRESH motor drive signal)
– Terminal 1J (24-pin, RECIRCULATE motor drive signal)
• Is there continuity?
Yes
Repair wiring harness between A/C amplifier and air intake actuator, then go to Step 8.
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 normal?
Yes
Go to next step.
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 A/C AMPLIFIER 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 normal?
Yes
Replace A/C amplifier, then go to next step.
No
Remove obstruction, or install doors in proper position. 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.
No
Recheck malfunction symptoms, then repeat from Step 1 if malfunction recurs.