Mazda 6 2002, Workshop Manual

Page: 1227 / 1248

U–76
TROUBLESHOOTING
End Of Sie
NO.9 NOISE WHILE OPERATING A/C SYSTEM
A6E858001038W11
9 INSPECT TO SEE WHETHER MALFUNCTION
IS IN REFRIGERANT PRESSURE SWITCH OR
REFRIGERANT AMOUNT
•
Inspect refrigerant pressure switch.
•
Is it okay?
Yes If refrigerant amount is empty, replace condenser, vaccum
refrigerant line
more than 30 minutes by vacuum pump,
and add refrigerant to specified level, then go to Step 17.
No Replace refrigerant pressure switch, then go to Step 17.
10 INSPECT TO SEE WHETHER MALFUNCTION
(LACK OF CONTINUITY) IS IN A/C CONTROL
SIGNAL CIRCUIT (BETWEEN A/C RELAY
AND PCM) OR ELSEWHERE
•
Does cool air blow out when terminal E of A/
C relay connector (A/C control signal) is
grounded?
Yes Release short, then go to next step.
No Go to Step 12.
11* INSPECT TO SEE WHETHER MALFUNCTION
(LACK OF CONTINUITY) IS IN PCM OR
WIRING HARNESS (BETWEEN A/C RELAY
AND PCM)
•
Test voltage at the A/C relay control signal
terminal of PCM.
•
Is voltage approximately 12 V ?
Yes Inspect PCM, then go to Step 17.
No Repair wiring harness between A/C relay and PCM, then go
to Step 17.
12* INSPECT TO SEE WHETHER MALFUNCTION
IS IN MAGNETIC CLUTCH OR ELSEWHERE
•
Test voltage at the following terminal of
magnetic clutch thermal protector.
— Terminal A (magnetic clutch operation
signal)
•
Is voltage approximately 12 V ?
Yes Inspect magnetic clutch, then go to Step 17.
No Go to next step.
13 INSPECT FUSE
•
Are A/C relay power supply fuses okay?
Yes Go to next step.
No Replace fuse, then go to Step 17. If fuse burns out
immediately, go to next step.
14 INSPECT WIRING HARNESS BETWEEN
FUSE BLOCK AND A/C RELAY FOR LACK
OF CONTINUITY
•
Test voltages at following terminals of A/C
relay.
— Terminal A (A/C relay control signal)
— Terminal C (A/C control signal)
•
Are voltages approximately 12 V ?
Yes Go to next step.
No Repair wiring harness between fuse block and A/C relay,
then go to Step 17.
15 INSPECT TO SEE WHETHER MALFUNCTION
IS IN A/C RELAY OR WIRING HARNESS
(BETWEEN A/C RELAY AND MAGNETIC
CLUTCH) AND EVAPORATOR
TEMPERATURE SENSOR
•
Test voltage at the following terminal of A/C
relay.
— Terminal D (magnetic clutch operation
signal)
•
Is voltage approximately 12 V ?
Yes Inspect wiring harness between A/C relay and magnetic
clutch.
•
If above wiring harness is OK, go to next step.
•
If above wiring harness malfunctions, repair wiring
harness, then go to Step 17.
No Replace A/C relay, then go to Step 17.
16 INSPECT EVAPORATOR TEMPERATURE
SENSOR
•
Inspect evaporator temperature sensor.
•
Is it okay?
Yes Go to next step.
No Replace evaporator temperature sensor, then go to next
step.
17 CONFIRM THAT MALFUNCTION SYMPTOMS
DO NOT RECUR AFTER REPAIR
•
Does cool air blow out? (Are the results of
refrigerant system performance test okay?)
Yes Troubleshooting completed. Explain repairs to customer.
No Recheck malfunction symptoms, then repeat from Step 1 if
malfunction recurs.
STEP INSPECTION ACTION
9 Noise while operating A/C system.
DESCRIPTION
•
Noise from magnetic clutch, A/C compressor, hose or refrigerant line.
POSSIBLE
CAUSE
•
Magnetic clutch operation noise (Step 4)
•
A/C compressor vane noise (Steps 5—13)
•
A/C compressor slippage noise (Steps 14—17)
•
Hose or refrigerant line interference noise (Step 18)