NO.2 AMOUNT OF AIR BLOWN FROM VENTS DOES NOT CHANGE

#
NO.2 AMOUNT OF AIR BLOWN FROM VENTS DOES NOT CHANGE

B3E070301038W04

## Full-auto Air Conditioner

2 | Amount of air blown from vents does not change.
DESCRIPTION | • Malfunction in blower system
POSSIBLE CAUSE | • A/C unit malfunction (Steps 3, 4, 12) • Blower motor malfunction (Steps 5-9) • Malfunction in power MOS FET system (Steps 10, 11, 13, 14) • Climate control unit malfunction (Step 15)

• 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, inspect make sure connectors, terminals and wiring harnesses are connected correctly and undamaged.

Diagnostic procedure

STEP | INSPECTION | ACTION
--- | --- | ---
1 | INSPECT HEATER 40 A FUSE • Inspect the HEATER 40 A fuse. • Is it normal? | Yes | Go to the next step.
No | Replace the fuse, then go to Step 15. If the fuse burns out immediately, go to the next step.
2 | INSPECT TO SEE WHETHER MALFUNCTION IS IN A/C UNIT OR ELSEWHERE • Turn the ignition switch to the ON position. • Recirculate air inside the vehicle. • Does the blower motor rotate smoothly? | Yes | Go to Step 4.
No | Go to the next step.
3 | INSPECT A/C UNIT INTAKE VENT • Is A/C unit intake vent clogged? | Yes | Remove obstruction, then go to Step 15.
No | Inspect if there are any obstruction in the A/C unit passage, then go to Step 15.

4*

INSPECT TO SEE WHETHER MALFUNCTION IS IN BLOWER RELAY SYSTEM OR POWER MOS FET SYSTEM

• Turn the ignition switch to ON position.
• Measure the voltage at the following blower motor terminal.

  - Terminal B (blower motor operation signal)

• Is voltage approx. 12 V?

Yes

Go to Step 8.

No | Go to the next step.

5*

INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (LACK OF CONTINUITY BETWEEN FUSE BLOCK AND BLOWER RELAY) OR ELSEWHERE

• Measure the voltage at the following blower relay terminals.

  - Terminal B (IG2 signal)
  - Terminal A (B+ signal)

• Is the voltage approx. 12 V?

Yes

Go to the next step.

No | Repair the wiring harness between the blower relay and HEATER 40 A fuse, then go to Step 15.

6*

INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (LACK OF CONTINUITY BETWEEN BLOWER RELAY AND GROUND) OR ELSEWHERE

• Measure the voltage at the following blower relay terminal.

  - Terminal D (GND signal)

• Is the voltage approx. 0 V?

Yes

Go to the next step.

No | Repair the wiring harness between the blower relay and ground, then go to Step 15.

7*

INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (LACK OF CONTINUITY BETWEEN BLOWER RELAY AND BLOWER MOTOR) OR BLOWER RELAY

• Measure the voltage at the following blower relay terminal.

  - Terminal E (blower motor operation signal)

• Is the voltage approx. 12 V?

Yes

Repair the wiring harness between the blower relay and blower motor, then go to Step 15.

No | Replace the blower relay, then go to Step 15.

8*

INSPECT TO SEE WHETHER MALFUNCTION IS IN BLOWER MOTOR OR ELSEWHERE

• Measure the voltage at the following blower motor terminal.

  - Terminal B (blower motor operation signal)

• Is the voltage approx. 12 V?

Yes

Go to the next step.

No | Inspect the blower motor, then go to Step 15.

9*

INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (LACK OF CONTINUITY BETWEEN BLOWER MOTOR AND POWER MOS FET) OR ELSEWHERE

• Measure the voltage at the following terminal of power MOS FET.

  - Terminal B (blower motor operation signal)

• Is voltage approx. 12 V?

Yes

Go to the next step.

No | Repair the wiring harness between the blower motor and power MOS FET, then go to Step 15.

10*

INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (LACK OF CONTINUITY BETWEEN POWER MOS FET AND GROUND) OR ELSEWHERE

• Measure the voltage at the following power MOS FET terminal.

  - Terminal A (blower motor operation signal)

• Is the voltage approx. 0 V?

Yes

Go to the next step.

No | Repair the wiring harness between the power MOS FET and ground, then go to Step 15.

11

INSPECT A/C UNIT

• Inspect the fan in A/C unit.

  - Is the fan free of interference with the A/C unit case?
  - Is the fan free of foreign material and obstruction?

• Is the fan normal?

Yes

Go to the next step.

No | Remove obstruction, repair or replace the fan and A/C unit case, then go to Step 15.

12*

INSPECT TO SEE WHETHER MALFUNCTION IS IN POWER MOS FET OR ELSEWHERE

• Disconnect power MOS FET connector.
• Measure the voltage at the following power MOS FET terminal.

  - Terminal B (blower motor control signal)

• Is voltage approx. 10 V?

Yes

Replace the power MOS FET, then go to Step 15.

No | Go to the next step.

13*

INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (LACK OF CONTINUITY BETWEEN POWER MOS FET AND CLIMATE CONTROL UNIT) OR ELSEWHERE

• Turn the ignition switch to the LOCK position.
• Disconnect climate control unit connector.
• Inspect for continuity at the following terminals between the power MOS FET and climate control unit.

  - Terminal B-F (blower motor control signal)
  - Terminal C-D (blower motor feedback signal)

• Is there continuity?

Yes

Go to the next step.

No | Repair the wiring harness between the power MOS FET and climate control unit, then go to Step 15.

14*

INSPECT TO SEE WHETHER MALFUNCTION IS IN CLIMATE CONTROL UNIT OR WIRING HARNESS (SHORT TO GROUND IN WIRING HARNESS BETWEEN POWER MOS FET AND CLIMATE CONTROL UNIT)

• Inspect for continuity at the following terminal between the power MOS FET and ground.

  - Terminal B (blower motor control signal)-ground

• Is there continuity?

Yes

Repair the wiring harness between the power MOS FET and ground, then go to the next step.

No | Replace the climate control unit, then go to the next step.
15 | CONFIRM THAT MALFUNCTION SYMPTOM DOES NOT RECUR AFTER REPAIR • Is air discharged from vent? | Yes | Troubleshooting completed. Explain repairs to customer.
No | Recheck malfunction symptoms, then repeat from Step 1 if the malfunction recurs.