Content .. 390 391 392 393 ..

Mazda 6. Manual - part 392

U–72

TROUBLESHOOTING

End Of Sie

NO.7 AIR FROM VENTS COLD ENOUGH

A6E858001038W09

Diagnostic procedure

INSPECT WIRING HARNESS BETWEEN
CLIMATE CONTROL UNIT AND AIR INTAKE
ACTUATOR FOR CONTINUITY

• Turn ignition switch to LOCK position.

• Is there continuity between following climate

control unit connector (12-pin) terminal and
air intake actuator connector terminal?
— Terminal D —Terminal 2K (FRESH

signal)

— Terminal F —Terminal 2I

(RECIRCULATE signal)

Yes

Go to next step.

Repair wiring harness between climate control unit and air
intake actuator, then go to Step 14.

*10

INSPECT WIRING HARNESS BETWEEN
CLIMATE CONTROL UNIT AND AIR INTAKE
ACTUATOR FOR SHORT TO GROUND

• Is there continuity between following climate

control unit connector (12-pin) terminal and
ground?
— Terminal 2K (FRESH signal)
— Terminal 2I (RECIRCULATE signal)

Yes

Repair wiring harness between climate control unit and air
intake actuator, then go to Step 14.

Go to next step.

*11

INSPECT WIRING HARNESS BETWEEN
CLIMATE CONTROL UNIT AND AIR INTAKE
ACTUATOR FOR SHORT TO B+

• Turn ignition switch to ON position

• Test voltage at following climate control unit

connector (12-pin) terminal.
— Terminal 2K (FRESH signal)
— Terminal 2I (RECIRCULATE signal)

• Is voltage approximately 12 V?

Yes

Repair wiring harness between climate control unit and air
intake actuator, then go to Step 14.

Replace climate control unit, then go to Step 14.

INSPECT BLOWER UNIT AIR INTAKE DOOR

• Is there any foreign material or obstruction in

blower unit air intake door?

Yes

Remove obstruction, then go to Step 14.

Go to next step.

VERIFY THAT BLOWER UNIT AIR INTAKE
DOOR IS POSITIONED SECURELY AND
PROPERLY

• Is blower unit air intake door securely and

properly positioned?

Yes

Inspect air intake door for cracks or damage, then go to next
step.

Install air intake door securely in proper position, then go to
next step.

VERIFY THAT MALFUNCTION SYMPTOM
OCCURS AFTER REPAIR

• Does malfunction disappear?

Yes

Troubleshooting completed.
Explain repairs to customer.

Recheck malfunction symptoms, then repeat from Step 1 if
malfunction recurs.

STEP

INSPECTION

ACTION

Air from vents not cold enough.

DESCRIPTION

• Magnetic clutch operates but A/C system malfunctions.

POSSIBLE

CAUSE

• Drive belt malfunction (Step 2)

• Malfunction in blower unit or condenser (Steps 4, 5)

• Malfunction in receiver/drier or expansion valve (valve closes too much) (Steps 8, 9)

• Malfunction in refrigerant lines (Steps 10, 11)

• A/C compressor system malfunction, insufficient compressor oil (Steps 15, 16)

• Over filling of compressor oil, malfunction in expansion valve or A/C unit air mix link system (Steps 17—

19)

STEP

INSPECTION

ACTION

INSPECT DRIVE BELT

• Inspect drive belt.

(See

B–3 DRIVE BELT INSPECTION

)

• Is it okay?

Yes

Go to next step.

Adjust or replace drive belt, then go to Step 20.

INSPECT REFRIGERANT SYSTEM
PERFORMANCE

• Perform refrigerant system performance test.

(See

U–13 REFRIGERANT SYSTEM

PERFORMANCE TEST

)

• Is operation normal?

Yes

Operation is normal. (Recheck malfunction symptoms.)

Go to next step.

TROUBLESHOOTING

U–73

CHECK TO SEE WHETHER MALFUNCTION
IS IN BLOWER UNIT INTAKE AND
CONDENSER OR ELSEWHERE

• Are refrigerant high-pressure and low-

pressure values both high?

Yes

Go to next step.

Go to Step 6.

INSPECT BLOWER UNIT INTAKE

• Is blower unit intake clogged?

Yes

Remove obstruction, then go to Step 20. (If air does not
reach evaporator within A/C unit, heat exchange does not
occur and refrigerant pressure becomes high.
Therefore, removal of obstruction is necessary.)

Go to next step.

INSPECT CONDENSER

• Inspect condenser.

(See

U–24 CONDENSER INSPECTION

)

• Is it okay?

Yes

Adjust refrigerant to specified amount, then go to Step 20.
(Excessive amount of refrigerant.)

Replace condenser, or repair and clean condenser fins,
then go to Step 20.

CHECK TO SEE WHETHER MALFUNCTION
IS IN EXPANSION VALVE, RECEIVER/DRIER
AND REFRIGERANT LINES OR ELSEWHERE

• Are refrigerant high-pressure and low-

pressure values low?

Yes

Go to next step.

Go to Step 14.

CHECK TO SEE WHETHER MALFUNCTION
IS IN EXPANSION VALVE AND RECEIVER/
DRIER OR ELSEWHERE

• Immediately after A/C compressor operates,

does refrigerant high-pressure value
momentarily rise to correct value, then fall
and stay below it? (Is there negative
pressure on low-pressure side?)

Yes

Go to next step.

Go to Step 10.

CHECK TO SEE WHETHER MALFUNCTION
IS IN EXPANSION VALVE OR RECEIVER/
DRIER

• Turn A/C switch off and let air conditioner

stop for 10 minutes.

• Start engine.

• Turn both A/C switch and fan switch on.

• Does malfunction occur after A/C

compressor turns on?

Yes

Go to next step.

Replace condenser and vacuum refrigerant line more than
30 minutes by vacuum pump, add refrigerant to specified
level, then go to Step 20. (Since water has intermixed in
receiver/drier and it is saturated, replacement is necessary.)

VERIFY THAT EXPANSION VALVE HEAT-
SENSING TUBE WITHIN A/C UNIT IS
POSITIONED SECURELY AND CORRECTLY

• Is expansion valve heat-sensing tube within

A/C unit securely installed in proper position?

Yes

Replace expansion valve, then go to Step 20. (Since valve
closes too much, replacement is necessary.)

Install heat-sensing tube securely in proper position, then go
to Step 20.

INSPECT REFRIGERANT LINES

• Inspect refrigerant lines.

— Is piping free of damage and cracks?
— Are piping connections free of oil grime?

(Visual inspection)

— Are piping connections free of gas

leakage?

— Are piping installation points on

condenser free of gas leakage?

— Are piping installation points on receiver/

drier free of gas leakage?

— Are piping installation points on A/C

compressor free of gas leakage?

— Are piping installation points on A/C unit

free of gas leakage?

— Perform gas leak inspection using gas

leak tester.

• Are above items okay?

Yes

Go to next step.

If piping or A/C component(s) are damaged or cracked,
replace them.
Then go to Step 20.
If there is no damage, go to Step 13.

INSPECT EVAPORATOR PIPING
CONNECTIONS IN A/C UNIT FOR GAS
LEAKAGE

• Are piping connections for evaporator in A/C

unit free of gas leakage?

Yes

If the vane makes a noise, add 10 ml {10 cc, 0.34 fl oz} of
compressor oil to the A/C compressor. Verify that the noise
is no longer heard.
Adjust refrigerant to specified amount, then go to Step 20.

If piping is damaged or cracked, replace it.
Then go to Step 20.
If there is no damage, go to next step.

STEP

INSPECTION

ACTION

U–74

TROUBLESHOOTING

End Of Sie

INSPECT EVAPORATOR PIPING
CONNECTIONS IN A/C UNIT FOR LOOSE

• Are piping connections for evaporator in A/C

unit loose?

Yes

Tighten connections with specified torque, adjust both
compressor oil and refrigerant to specified amount, then go
to Step 20.

If the vane makes a noise, add 10 ml {10 cc, 0.34 fl oz} of
compressor oil to the A/C compressor. Verify that the noise
is no longer heard.
Replace O-ring on piping, adjust refrigerant to specified
amount, then go to Step 20.

INSPECT PIPING CONNECTIONS FOR
LOOSE

• Are piping connections loose?

Yes

Tighten connections with specified torque, adjust both
compressor oil and refrigerant to specified amount, then go
to Step 20.

CHECK TO SEE WHETHER MALFUNCTION
IS IN EXPANSION VALVE, AIR MIX
ACTUATOR AND COMPRESSOR OIL OR
ELSEWHERE

• Does refrigerant high-pressure value hardly

increase?

Yes

Go to next step. (Pressure hardly increases.)

Go to Step 17.

CHECK TO SEE WHETHER MALFUNCTION
IS IN COMPRESSOR OIL AMOUNT AND A/C
COMPRESSOR OR ELSEWHERE

• When engine is racing, does high-pressure

value increase?

Yes

Return to Step 3.

Go to next step.

CHECK TO SEE WHETHER MALFUNCTION
IS IN COMPRESSOR OIL AMOUNT OR A/C
COMPRESSOR

• After compressor oil is replenished each 10

ml {10 cc, 0.34 fl oz}, does high-pressure
value increase?

Yes

Troubleshooting completed. (Explain to customer that cause
was insufficient compressor oil.)

Replace A/C compressor, then go to Step 20. (Cause is
defective A/C compressor.)

CHECK TO SEE WHETHER MALFUNCTION
IS IN EXPANSION VALVE OR ELSEWHERE

• Is only refrigerant low-pressure value high?

Yes

Go to Step 19.

Go to next step.

VERIFY THAT AIR MIX IS INSTALLED
SECURELY AND PROPERLY

• Are A/C unit air mix links, air mix cranks, and

air mix rods securely and properly installed?

Yes

Set fan switch to 4th position.
Turn A/C switch on.
Set FRESH mode.
Set temperature control to MAX COLD.
Set VENT mode.

(1)Start and run the engine at 1,500 rpm for 10 minutes.
(2)Run the engine at idle for 1 minute.
(3)Within 12 seconds, idle

→ 4,000 rpm → idle. Perform

cycle 5 times.

(4) Run the engine at idle for 30 seconds.
(5)Drain the compressor oil completely from the A/C

compressor and verify the amount.

• If there is approximately 90 ml {90 cc, 3.0 fl oz} of

compressor oil, go to Step 20.

• If there is more than 90 ml {90 cc, 3.0 fl oz} of

compressor oil, remove surplus oil and fill A/C
compressor with 90 ml {90 cc, 3.0 fl oz} of
compressor oil. Repeat Steps (1) to (5).

(Cause is excessive amount of compressor oil.)

Repair or install links, cranks and rods securely in proper
position, then go to Step 20.

VERIFY THAT EXPANSION VALVE HEAT-
SENSING TUBE WITHIN A/C UNIT IS
POSITIONED SECURELY AND CORRECTLY

• Is expansion valve heat-sensing tube within

A/C unit securely installed in proper position?

Yes

Replace expansion valve, then go to next step. (Since valve
opens too much, replacement is necessary.)

Install heat-sensing tube securely in proper position, then go
to next step.

VERIFY THAT MALFUNCTION SYMPTOM
OCCURS AFTER REPAIR

• Does cool air blow out? (Are results of

refrigerant system performance test okay?)

Yes

Troubleshooting completed.
Explain repairs to customer.

Recheck malfunction symptoms, then repeat from Step 1 if
malfunction recurs.

STEP

INSPECTION

ACTION

TROUBLESHOOTING

U–75

NO.8 NO COOL AIR

A6E858001038W10

• 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

No cool air

DESCRIPTION

• Magnetic clutch does not operate.

POSSIBLE

CAUSE

• Malfunction in PCM A/C cut control system (Step 3)

• Malfunction in climate control unit (Step 4)

• Malfunction in refrigerant pressure switch (Steps 5, 7—9)

• Malfunction in PCM (A/C signal) (Step 6)

• Malfunction in PCM (IG1 signal) (Steps 10, 11)

• Malfunction in A/C compressor (Step 12)

• Malfunction in A/C relay (Steps 13—15)

• Malfunction in evaporator temperature sensor (Step 16)

STEP

INSPECTION

ACTION

INSPECT AIR BLOW OUT

• Does air blow out?

Yes

Go to next step.

Go to Step 1 of troubleshooting indexes No.1 and 2.

INSPECT A/C COMPRESSOR OPERATION

• Start engine.

• Turn A/C switch and fan switch on.

• Does A/C compressor operate?

Yes

Go to Step 1 of troubleshooting index No.7.

Go to next step.

INSPECT FOR DTC IN PCM

• Inspect for DTCs related to the PCM on-

board diagnostic system.

• Are any DTCs displayed?

Yes

Go to appropriate inspection procedure.

Go to next step.

INSPECT TO SEE WHETHER MALFUNCTION
IS IN CLIMATE CONTROL UNIT OR
ELSEWHERE

• Does cool air blow out when terminal 1P of

climate control unit connector (24-pin, A/C
signal) is grounded?

Yes

Replace climate control unit, then go to Step 17.

Release short, then go to next step.

INSPECT TO SEE WHETHER MALFUNCTION
IS IN A/C SIGNAL CIRCUIT (BETWEEN
REFRIGERANT PRESSURE SWITCH AND
PCM) OR ELSEWHERE

• Test voltage at following terminal of

refrigerant pressure switch.
— Terminal B (A/C signal)

• Is voltage approximately 12 V?

Yes

Go to Step 7.

Go to next step.

INSPECT TO SEE WHETHER MALFUNCTION
(LACK OF CONTINUITY) IS IN WIRING
HARNESS (BETWEEN REFRIGERANT
PRESSURE SWITCH AND PCM) OR PCM

• Test voltage at A/C signal terminal of PCM.

• Is voltage approximately 12 V?

Yes

Repair wiring harness between PCM and refrigerant
pressure switch, then go to Step 17.

Inspect PCM, then go to Step 17.

INSPECT TO SEE WHETHER MALFUNCTION
IS IN REFRIGERANT PRESSURE SWITCH,
REFRIGERANT AMOUNT, OR ELSEWHERE

• Does cool air blow out when terminals A and

B of refrigerant pressure switch connector
are shorted?

Yes

Go to Step 9.

Go to next step.

INSPECT TO SEE WHETHER MALFUNCTION
IS IN WIRING HARNESS (BETWEEN
REFRIGERANT PRESSURE SWITCH AND
CLIMATE CONTROL UNIT) OR ELSEWHERE

• Test voltage at following terminal of climate

control unit.
— Terminal 1P (24-pin, A/C signal)

• Is voltage approximately 12 V?

Yes

Go to Step 10.

Repair wiring harness between refrigerant pressure switch
and climate control unit, then go to Step 17.

Content .. 390 391 392 393 ..