Mazda 6 2002 - Page 1157

ON-BOARD DIAGNOSTIC, TROUBLESHOOTING
U67
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End Of Sie
NO.3 AMOUNT OF AIR BLOWN FROM VENTS DOES NOT CHANGE
A6E858001038W05
Manual Air Conditioner
Diagnostic procedure
12* INSPECT TO SEE WHETHER MALFUNCTION
IS IN POWER MOS FET OR ELSEWHERE
• Disconnect power MOS FET connector.
• Test voltage at the following terminal of
power MOS FET.
 Terminal B (blower motor control signal)
• Is voltage approximately 10 V?
Yes Replace power MOS FET, then go to Step 15.
No Go to 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 ignition switch to LOCK position.
• Disconnect climate control unit connector.
• Inspect for continuity at the following
terminals between power MOS FET and
climate control unit.
 Terminal B1C (24-pin, blower motor
control signal)
 Terminal C1A (24-pin, blower motor
feedback signal)
• Is there continuity?
Yes Go to next step.
No Repair wiring harness between 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 BETWEEN
POWER MOS FET AND CLIMATE CONTROL
UNIT)
• Inspect for continuity at the following terminal
between power MOS FET and ground.
 Terminal B (blower motor control signal)
ground
• Is there continuity?
Yes Repair wiring harness between power MOS FET and
ground, then go to next step.
No Replace climate control unit, then go to next step.
15 CONFIRM THAT MALFUNCTION SYMPTOMS
DO 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
malfunction recurs.
STEP INSPECTION ACTION
3 Amount of air blown from vents does not change.
DESCRIPTION • Malfunction in blower system.
POSSIBLE
CAUSE
• Blower relay, blower motor, resistor, fan switch malfunction (Step 1)
• Blower unit malfunction (Steps 24)
STEP INSPECTION ACTION
1 INSPECT BLOWER SYSTEM
• Inspect the following systems and electrical
parts.
 Blower relay
Blower motor
Resistor
 Fan switch
 Related wiring harnesses
• Are they okay?
Yes Go to next step.
No Repair or replace malfunctioning part, then go to Step 5.
2 CHECK TO SEE WHETHER MALFUNCTION
IS IN BLOWER UNIT OR ELSEWHERE
• Turn ignition switch to ON position.
• Turn fan switch on.
• Recirculate air inside vehicle.
• Does fan in blower unit rotate smoothly?
Yes Go to Step 4.
No Go to next step.