Mazda CX 7. Manual — part 285

SYMPTOM TROUBLESHOOTING

07-03–13

07-03

NO.7 AIR FROM VENTS NOT COLD ENOUGH

id070300801000

Diagnostic procedure

7

Air from vents not cold enough.

DESCRIPTION

• Magnetic clutch operates but A/C system malfunctions.

POSSIBLE

CAUSE

• Drive belt malfunction

• A/C unit or condenser malfunction

• Receiver/drier or expansion valve malfunction (valve closes too much)

• Malfunction in refrigerant lines

• A/C compressor system malfunction, insufficient compressor oil

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

STEP

INSPECTION

ACTION

1

INSPECT DRIVE BELT

• Inspect the drive belt.

(See 01-10-3 DRIVE BELT INSPECTION[L3
WITH TC].)

• Is it normal?

Yes

Go to the next step.

No

Adjust or replace the drive belt, then go to Step 20.
(See 01-10-3 DRIVE BELT REMOVAL/INSTALLATION[L3
WITH TC].)

2

INSPECT REFRIGERANT SYSTEM
PERFORMANCE

• Perform refrigerant system performance test.

(See 07-10-6 REFRIGERANT SYSTEM
PERFORMANCE TEST.)

• Is the operation normal?

Yes

Operation is normal. (Recheck malfunction symptoms.)

No

Go to the next step.

3

INSPECT TO SEE WHETHER MALFUNCTION
IS IN A/C UNIT INTAKE AND CONDENSER
OR ELSEWHERE

• Are the refrigerant high-pressure and low-

pressure values both high?

Yes

Go to the next step.

No

Go to Step 6.

4

INSPECT A/C UNIT INTAKE

• Is the A/C unit intake clogged?

Yes

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

No

Go to the next step.

5

INSPECT CONDENSER

• Inspect the condenser.

(See 07-11-18 CONDENSER
INSPECTION.)

• Is it normal?

Yes

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

No

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

6

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

• Are the refrigerant high-pressure and low-

pressure values low?

Yes

Go to the next step.

No

Go to Step 14.

7

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

• Immediately after the A/C compressor

operates, does the 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 the next step.

No

Go to Step 10.

8

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

• Turn the A/C switch off and let the air

conditioner stop for 10 min.

• Start the engine.

• Turn the both A/C switch and airflow volume

control dial on.

• Does the malfunction occur after the A/C

compressor turns on?

Yes

Go to the next step.

No

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

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SYMPTOM TROUBLESHOOTING

07-03–14

9

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

• Is the expansion valve heat-sensing tube in

the A/C unit securely installed in the proper
position?

Yes

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

No

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

10

INSPECT REFRIGERANT LINE

• Inspect the refrigerant lines.

— Is the piping free of damage and cracks?

— Are the piping connections free of oil

grime? (Visual inspection)

— Are the piping connections free of gas

leakage?

— Are the piping installation points on the

condenser free of gas leakage?

— Are the piping installation points on the

receiver/drier free of gas leakage?

— Are the piping installation points on the A/

C compressor free of gas leakage?

— Are the piping installation points on the A/

C unit free of gas leakage?

— Perform gas leakage inspection using a

gas leak tester.

• Are the above items normal?

Yes

Go to the next step.

No

If the 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.

11

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

• Are piping the connections for the evaporator

in the 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 the specified amount, then go to Step
20.

No

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

12

INSPECT EVAPORATOR PIPING
CONNECTION IN A/C UNIT FOR LOOSE

• Are the piping connections for the evaporator

in the A/C unit loose?

Yes

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

No

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 the O-ring on piping, adjust refrigerant to the
specified amount, then go to Step 20.

13

INSPECT PIPING CONNECTION FOR LOOSE

• Are the piping connections loose?

Yes

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

No

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.

14

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

• Does the refrigerant high-pressure value

hardly increase?

Yes

Go to the next step. (Pressure hardly increases.)

No

Go to Step 17.

15

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

• When the engine is racing, does the high-

pressure value increase?

Yes

Return to Step 3.

No

Go to the next step.

16

INSPECT 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.)

No

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

STEP

INSPECTION

ACTION

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SYMPTOM TROUBLESHOOTING

07-03–15

07-03

2007 Mazda CX-7 Workshop Manual (1871–1U–06B)

End Of Sie

NO.8 NO COOL AIR

id070300801100

• 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

17

INSPECT TO SEE WHETHER MALFUNCTION
IS IN EXPANSION VALVE OR ELSEWHERE

• Is only refrigerant low-pressure value high?

Yes

Go to Step 19.

No

Go to the next step.

18

VERIFY THAT AIR MIX IS INSTALLED
SECURELY AND PROPERLY

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

and air mix rods securely and properly
installed?

Yes

Set the airflow volume control dial to 4th position.
Turn the 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 min.
(2)Run the engine at idle for 1 min.
(3)Within 12 s, idle

→ 4,000 rpm → idle. Perform cycle 5

times.

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

compressor and verify the amount.

• If there is approx. 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 the 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.)

No

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

19

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

• Is the expansion valve heat-sensing tube in

the A/C unit securely installed in the proper
position?

Yes

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

No

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

20

VERIFY THAT MALFUNCTION SYMPTOM
OCCURS AFTER REPAIR

• Does cool air blow out? (Are results of

refrigerant system performance test
normal?)

Yes

Troubleshooting completed.
Explain repairs to customer.

No

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

STEP

INSPECTION

ACTION

8

No cool air

DESCRIPTION

• Magnetic clutch does not operate.

POSSIBLE

CAUSE

• Malfunction in PCM A/C cut control system

• Malfunction in climate control unit

• Malfunction in refrigerant pressure switch

• Malfunction in PCM (A/C signal)

• Malfunction in PCM (IG1 signal)

• Malfunction in A/C compressor

• Malfunction in A/C relay

• Malfunction in evaporator temperature sensor

• Malfunction in BCM unit (Manual A/C)

• Malfunction in CAN communication

STEP

INSPECTION

ACTION

1

INSPECT AIR BLOW OUT

• Does air blow out?

Yes

Go to the next step.

No

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

2

INSPECT A/C COMPRESSOR OPERATION

• Start engine.

• Turn A/C switch and airflow volume control

dial on.

• Does A/C compressor operate?

Yes

Go to Step 1 of troubleshooting index No.7.

No

Go to the next step.

SYMPTOM TROUBLESHOOTING

07-03–16

2007 Mazda CX-7 Workshop Manual (1871–1U–06B)

Revised 8/2006 (Ref. No. R087/06)

3

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.

No

(Auto A/C)
Go to the next step.
(Manual A/C)
Go to Step 5.

4

CONFIRM DTC U0073, U0516 USING M-MDS

• Retrieve DTC from EATC and HEC.

• DTCs (U0073, U0516) retrieved?

Yes

Network communication, for related system is malfunction.
Go to appropriate inspection procedure.

No

Go to Step 6.

5

INSPECT TO SEE WHETHER MALFUNCTION
IS IN PCM OR ELSEWHERE

• Does cool air blow out when terminal 1AU of

PCM connector (A/C signal) is grounded?

Yes

Inspect and/or replace the PCM, then go to Step 18.

No

Release short, then go to the next step.

6*

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 approx. 12 V?

Yes

Go to Step 8.

No

Go to the next step.

7*

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 approx. 12 V?

Yes

Repair wiring harness between PCM and refrigerant
pressure switch, then go to Step 18.

No

Inspect PCM, then go to Step 18.

8

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 10.

No

(Auto A/C)
Go to Step 11.
(Manual A/C)
Go to the next step.

9*

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

• Test voltage at following terminal of PCM.

— Terminal 1AU (A/C signal)

• Is voltage approx. 12 V?

Yes

Go to Step 11.

No

Repair wiring harness between refrigerant pressure switch
and PCM, then go to Step 18.

10

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, vacuum
refrigerant line more than 30 min by vacuum pump, and
add refrigerant to specified level, then go to Step 18.

No

Replace refrigerant pressure switch, then go to Step 18.

11

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 the next step.

No

Go to Step 13.

12*

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 approx. 12 V?

Yes

Inspect PCM, then go to Step 18.

No

Repair wiring harness between A/C relay and PCM, then go
to Step 18.

13*

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 approx. 12 V?

Yes

Inspect magnetic clutch, then go to Step 18.

No

Go to the next step.

STEP

INSPECTION

ACTION