Mazda CX 7. Manual - part 93

SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–69

01-03

NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY[L3 WITH TC]

id010339803000

Diagnostic procedure

End Of Sie

24

A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY.

DESCRIPTION

A/C compressor magnetic clutch does not disengage.

POSSIBLE CAUSE

• A/C compressor magnetic clutch engagement is stuck.

• A/C relay is stuck closed.

• Short to ground between A/C switch and PCM

• Short to ground circuit between A/C relay and PCM

• A/C relay to magnetic clutch circuit shorted to battery power

STEP

INSPECTION

RESULTS

ACTION

1

Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON position 
(Engine off).
Retrieve any DTCs.
Are there any DTCs displayed?

Yes

DTC is displayed:
Go to the appropriate DTC test.

No

No DTC is displayed:
Go to the next step.

2

Start the engine and idle it.
Turn the A/C switch on.
Remove the A/C relay.
Does the A/C magnetic clutch disengage?

Yes

Inspect for the following:

• A/C relay is stuck closed.

• Short to ground circuit between A/C relay and PCM 

terminal 1I.

If both items normal, go to the next step.

No

Inspect if circuit between A/C relay and magnetic clutch 
shorts to battery power circuit.
If circuit is normal, inspect magnetic clutch for stuck 
engagement or clearance.

3

Disconnect the refrigerant pressure switch 
connector.
Start the engine and turn the A/C switch on.

Note

• A/C should not work when disconnecting 

connector. If A/C remains working, short 
to ground circuit may be present.

Does A/C remain working?

Yes

Inspect for a short to ground circuit between refrigerant 
pressure switch and PCM terminal 1AU.

No

Go to the next step.

4

Reconnect refrigerant pressure switch 
connector.
Turn off A/C switch.

Note

• A/C should not work when turning A/C 

switch off. If A/C remains working, short to 
ground circuit may be present.

Does A/C remain working?

Yes

Inspect for the following:

• Short to ground circuit between A/C switch and A/C 

amplifier

• Short to ground circuit between A/C amplifier and 

refrigerant pressure switch

No

Inspect the whether A/C switch is stuck closed.

5

Verify test results.

• If normal, return to the diagnostic index to service any additional symptoms.

• If a malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform the 

repair or diagnosis.
— If the vehicle is repaired, troubleshooting is completed.

— If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later 

calibration is available. Retest.le. Retest.

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SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–70

NO.25 A/C IS NOT CUT OFF UNDER WIDE OPEN THROTTLE CONDITIONS[L3 WITH TC]

id010339803100

Diagnostic procedure

End Of Sie

NO.26 EXHAUST SULPHUR SMELL[L3 WITH TC]

id010339803200

Diagnostic procedure

25

A/C IS NOT CUT OFF UNDER WOT CONDITIONS.

DESCRIPTION

A/C compressor magnetic clutch does not disengage under WOT.

POSSIBLE CAUSE

• Accelerator position sensor malfunction

• Loosely installed accelerator position sensor.

STEP

INSPECTION

RESULTS

ACTION

1

Does the A/C compressor disengage when A/C 
switch is turned off?

Yes

Go to the next step.

No

Go to symptom troubleshooting “No.24 A/C is always 
on or A/C compressor runs continuously”.

2

Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON position 
(Engine off).
Retrieve any DTCs.
Are there any DTCs displayed?

Yes

DTC is displayed: 
Go to appropriate DTC test.

No

No DTC is displayed: 
Inspect the accelerator position sensor.

3

Verify test results.

• If normal, return to the diagnostic index to service any additional symptoms.

• If a malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform the 

repair or diagnosis.
— If the vehicle is repaired, troubleshooting is completed.

— If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later 

calibration is available. Retest.le. Retest.

26

EXHAUST SULPHUR SMELL

DESCRIPTION

Rotten egg smell (sulphur) from exhaust

POSSIBLE CAUSE

• Electrical connectors are disconnected or connected poorly

• Charcoal canister malfunction

• Vacuum lines are disconnected or connected improperly.

• Improper fuel pressure

• Poor fuel quality

Warning
The following troubleshooting flow chart contains fuel system diagnosis and repair 
procedures. Read following warnings before servicing fuel system: 

• Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always 

keep sparks and flames away from fuel.

• Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or 

death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete 
“BEFORE REPAIR PROCEDURE” and “AFTER REPAIR PROCEDURE” described in this 
manual.
 (See 01-14-4 BEFORE REPAIR PROCEDURE[L3 WITH TC].)
 (See 01-14-4 AFTER REPAIR PROCEDURE[L3 WITH TC].)

Caution

• Disconnecting/connecting the quick release connector without cleaning it may possibly 

cause damage to the fuel pipe and quick release connector. Always clean the quick release 
connector joint area before disconnecting/connecting, and make sure that it is free of 
foreign material.

STEP

INSPECTION

RESULTS

ACTION

1

Are any driveability or exhaust smoke concerns 
present?

Yes

Go to the appropriate flow chart.

No

Go to the next step.

2

Inspect for the following: 

• Electrical connections

• Vacuum lines

• Fuel quality

Are all items normal?

Yes

Go to the next step.

No

Service if necessary.
Repeat Step 2.

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SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–71

01-03

End Of Sie

NO.27 FUEL REFILL CONCERNS[L3 WITH TC]

id010339803300

3

Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON position 
(Engine off).
Retrieve any DTCs.
Are there any DTCs displayed?

Yes

DTC is displayed: 
Go to the appropriate DTC test.

No

No DTC is displayed: 
Go to the next step.

4

Access and monitor FUEL_PRES PID.
Is the FUEL_PRES PID value within the 
specified?
(See 01-40-6 PCM INSPECTION[L3 WITH TC].)

Yes

Go to Step 8.

No

Go to the next step.

5

Is vehicle accelerate performance normally?

Yes

Go to the next step.

No

Go to Step 7.

6

Inspect the fuel pressure sensor.
(See 01-40-35 FUEL PRESSURE SENSOR 
INSPECTION[L3 WITH TC].)
Is the fuel pressure sensor normal?

Yes

Go to Step 8.

No

Go to the next step.

7

Replace the high pressure fuel pump.
Monitor FUEL_PRES PID.
Is the FUEL_PRES PID value within the 
specified?
(See 01-40-6 PCM INSPECTION[L3 WITH TC].)

Yes

Troubleshooting is completed.
Go to Step 9.

No

Go to the next step.

8

Inspect the charcoal canister for fuel saturation.
Is excess amount of liquid fuel present in 
canister?

Yes

Replace the charcoal canister.

No

Inspect the fuel tank vent system.
If fuel tank vent system is normal, suggest trying a 
different brand since sulfur content can vary in different 
fuels.
If fuel tank vent system is not normal, repair or replace 
the malfunctioning parts.

9

Verify test results.

• If normal, return to the diagnostic index to service any additional symptoms.

• If a malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform the 

repair or diagnosis.

— If the vehicle is repaired, troubleshooting is completed.

— If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later 

calibration is available. Retest.le. Retest.

STEP

INSPECTION

RESULTS

ACTION

27

Fuel refill concerns

DESCRIPTION

• Fuel tank does not fill smoothly.

POSSIBLE 

CAUSE

• Clogged EVAP pipes

• Nonreturn valve malfunction

• Improper use of fuel nozzle

• Inadequate fuel filling speed

Warning
• The following troubleshooting flow chart contains the fuel system diagnosis and repair 

procedures. Read the following warnings before servicing the fuel system:
— Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always 

keep sparks and flames away from fuel.

— Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or 

death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete 
“BEFORE REPAIR PROCEDURE” and “AFTER REPAIR PROCEDURE” described in this 
manual.

 (See01-14-4 BEFORE REPAIR PROCEDURE[L3 WITH TC].)
 (See01-14-4 AFTER REPAIR PROCEDURE[L3 WITH TC].)

Caution

• Disconnecting/connecting the quick release connector without cleaning it may possibly 

cause damage to the fuel pipe and quick release connector. Always clean the quick release 
connector joint area before disconnecting/connecting, and make sure that it is free of foreign 
material.

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SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–72

Diagnostic procedure

End Of Sie

NO.28 FUEL FILLING SHUT OFF ISSUES[L3 WITH TC]

id010339803400

Diagnostic procedure

STEP

INSPECTION

ACTION

1

Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON position 
(Engine off).
Retrieve any DTCs.
Are there any DTCs displayed?

Yes

DTC is displayed:
Go to the appropriate DTC test.

No

No DTC is displayed:
Go to the next step.

2

Remove the fuel-filler pipe.
Make sure nonreturn valve is installed properly.
Inspect the nonreturn valve operation.
Is nonreturn valve normal?

Yes

Inspect for the following:

• Improper use of fuel nozzle

• Inadequate fuel filling speed

No

Nonreturn valve is installed improperly:

• Reinstall the nonreturn valve to proper position.

Nonreturn valve does not operate properly:

• Replace the nonreturn valve.

3

Verify test results.

• If normal, return to the diagnostic index to service any additional symptoms.

• If a malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform the 

repair or diagnosis.

— If the vehicle is repaired, troubleshooting is completed.

— If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later 

calibration is available. Retest.le. Retest.

28

Fuel filling shut off issues

DESCRIPTION

• Fuel does not shut off properly.

POSSIBLE 

CAUSE

• Clogged EVAP pipes

• Nonreturn valve malfunction

• Fuel shut-off valve malfunction

• Fuel nozzle malfunction

• Fuel nozzle is not inserted correctly.

Warning
• The following troubleshooting flow chart contains the fuel system diagnosis and repair 

procedures. Read the following warnings before servicing the fuel system:

— Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always 

keep sparks and flames away from fuel.

— Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injuries or 

death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete 
“BEFORE REPAIR PROCEDURE” and “AFTER REPAIR PROCEDURE” described in this 
manual.

 (See01-14-4 BEFORE REPAIR PROCEDURE[L3 WITH TC].)
 (See01-14-4 AFTER REPAIR PROCEDURE[L3 WITH TC].)

Caution

• Disconnecting/connecting the quick release connector without cleaning it may possibly 

cause damage to the fuel pipe and quick release connector. Always clean the quick release 
connector joint area before disconnecting/connecting, and make sure that it is free of foreign 
material.

STEP

INSPECTION

ACTION

1

Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON position 
(Engine off).
Retrieve any DTCs.
Are there any DTCs displayed?

Yes

DTC is displayed:
Go to the appropriate DTC test.

No

No DTC is displayed:
Go to the next step.

2

Remove the fuel-filler pipe.
Make sure nonreturn valve is installed properly.
Inspect the nonreturn valve operation.
Is nonreturn valve normal?

Yes

Inspect for the following:

• Improper use of fuel nozzle

• Fuel is not inserted correctly.

• Inspect fuel shut-off valve.

No

Nonreturn valve is installed improperly:

• Reinstall the nonreturn valve to proper position.

Nonreturn valve does not operate properly:

• Replace the nonreturn valve.

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