Mazda CX 7. Manual - part 85

 

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Mazda CX 7. Manual - part 85

 

 

SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–37

01-03

NO.9 FAST IDLE/RUNS ON[L3 WITH TC]

id010339801500

9

FAST IDLE/RUNS ON

DESCRIPTION

• Engine speed continues at fast idle after warm-up.

• Engine runs after the ignition switch is turned off.

POSSIBLE CAUSE

• ECT sensor or related circuit malfunction

• Suction control valve (built-in high pressure fuel pump)

• Fuel injector malfunction

• Air leakage from intake-air system

• Throttle body malfunction

• Accelerator pedal position sensor or related circuit malfunction

• Cruise control system operation improperly

• Improper load signal input

• Improper operation of electric throttle control system

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

• 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 injury or 

death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete 
“BEFORE REPAIR ROCEDURE” 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]

01-03–38

Diagnostic procedure

End Of Sie

STEP

INSPECTION

RESULTS

ACTION

1

Connect the M-MDS to the DLC.
Access the ECT PID.
Start and warm-up engine to normal operating 
temperature.
Is ECT PID reading between82— 112 

°C {180— 

234 

°F}?

Yes

Go to the next step.

No

ECT PID is higher than 112 

°C {234 °F}:

Go to symptom troubleshooting "NO.17 COOLING 
SYSTEM CONCERNS - OVERHEATING".
ECT PID is less than 82 

°C {180 °F}

Go to symptom troubleshooting "NO.18 COOLING 
SYSTEM CONCERNS - RUNS COLD".

2

Perform the self-test function using the M-MDS.
Turn the ignition switch to the ON position.
Retrieve any DTCs.
Is a DTC displayed?

Yes

DTC is displayed:
Go to the appropriate DTC test.
(See01-02-13 DTC TABLE[L3 WITH TC].)

No

No DTC is displayed:
Go to the next step.

3

Inspect for leakage in intake-air system.
Is there any leakage found?

Yes

Repair or replace for leakage.

No

Go to the next step.

4

Perform the TP sweep inspection.
(See01-03-78 ENGINE CONTROL SYSTEM 
OPERATION INSPECTION[L3 WITH TC].)
Does the electronic throttle control system work 
properly?

Yes

Visually inspect the throttle body (damaged/
scratching.) If normal, go to the next step.

No

Inspect or replace the malfunctioning parts, according 
to the inspection results.

5

Connect the M-MDS to the DLC-2.
Access and monitor the following PIDs using the 
data monitor function.

• ECT

• APP

• ACSW

• PSP (PCM terminal 2T)

Do the PIDs indicate the correct values under 
trouble condition?
(See01-40-6 PCM INSPECTION[L3 WITH TC].)

Yes

Go to the next step.

No

Inspect and repair or replace suspected parts and the 
related harnesses.
If the malfunction remains, perform the intermittent 
concern troubleshooting.
(See01-03-76 INTERMITTENT CONCERN 
TROUBLESHOOTING[L3 WITH TC].)

6

Inspect the high pressure fuel pump.
(See01-14-19 HIGH PRESSURE FUEL PUMP 
INSPECTION[L3 WITH TC].)
Is the high pressure fuel pump normal?

Yes

Go to the next step.

No

Replace the high pressure fuel pump.

7

Inspect the fuel injector for each cylinder.
(See01-14-27 FUEL INJECTOR 
INSPECTION[L3 WITH TC].)
Are fuel injectors normal?

Yes

Go to the next step.

No

Replace the suspected fuel injector.
(See01-14-23 FUEL INJECTOR REMOVAL/
INSTALLATION[L3 WITH TC].)

8

Inspect the operation of cruise control system.
Does the cruise control system work properly?

Yes

Inspect and repair or replace the injector driver module 
or related circuit.

No

Repair or replace the malfunctioning part according to 
inspection results.

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.

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SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–39

01-03

NO.10 LOW IDLE/STALLS DURING DECELERATION[L3 WITH TC]

id010339801600

Diagnostic procedure

10

LOW IDLE/STALLS DURING DECELERATION

DESCRIPTION

• Engine stops unexpectedly at beginning of deceleration or recovery from deceleration.

POSSIBLE CAUSE

• Poor fuel quality

• Vacuum leakage

• Improper operation of electronic throttle control system

• Air leakage from intake-air system

• Intake-air system restriction

• EVAP control system malfunction

• Improper air/fuel mixture ratio control

• Erratic signal from CKP sensor

• Erratic signal from CMP sensor

• Accelerator position sensor or related circuit malfunction

• TP sensor or related circuit malfunction

• MAF sensor or related circuit malfunction

• Front and/or rear HO2S sensor or related circuit malfunction

• Brake switch or related circuit malfunction

• TR switch or related circuit malfunction

• Improper A/C magnetic clutch operation

• Inadequate fuel pressure (high or low pressure side)

• Suction control valve malfunction (built-in high pressure fuel pump)

• Relief valve malfunction (built-in delivery pipe)

• Fuel leakage

• Fuel line restriction

• Fuel filter clogging

• Incorrect fuel injection timing

• High pressure fuel pump malfunction

• Fuel injector malfunction

• Low engine compression

• Improper valve timing

• EGR system malfunction

• Vacuum leakage

• ECT sensor or related circuit malfunction

• Fuel pressure sensor or related circuit malfunction

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

• 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 injury or 

death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete 
“BEFORE REPAIR ROCEDURE” 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

RESULTS

ACTION

1

Does the engine idle rough?

Yes

Go to symptom troubleshooting “NO.8 ENGINE RUNS 
ROUGH/ROLLING IDLE”.
(See01-03-34 NO.8 ENGINE RUNS ROUGH/
ROLLING IDLE[L3 WITH TC].)

No

Go to the next step.

2

Verify the following:

• Fuel quality (proper octane, contamination, 

winter/summer blend)

• Intake-air system restriction or leakage

• Fuel leakage in fuel system

• Vacuum leakage

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]

01-03–40

3

Inspect CMP and CKP sensor for the following;

• Installation condition

(See01-40-45 CAMSHAFT POSITION 
(CMP) SENSOR REMOVAL/
INSTALLATION[L3 WITH TC].)
(See01-40-42 CRANKSHAFT POSITION 
(CKP) SENSOR REMOVAL/
INSTALLATION[L3 WITH TC].)

• Damaged trigger wheel and camshaft

• Open or short circuit in the wiring harnesses

Is there any malfunction detected?

Yes

Repair or replace the malfunctioning part according 
inspection results.

No

Go to the next step.

4

Perform the self-test function using the M-MDS.
Turn the ignition switch to the ON position.
Retrieve any DTCs.
Is a DTC displayed?

Yes

DTC is displayed:
Go to the appropriate DTC test.
(See01-02-13 DTC TABLE[L3 WITH TC].)

No

No DTC is displayed:
Go to the next step.

5

Connect the M-MDS to the DLC-2.
Access and monitor the following PIDs using the 
data monitor function.

• ACSW

• APP

• BOO

• ECT

• MAF

• TP

• O2S11

• O2S12

• LONGFT1

• SHTFT1

• PSP (PCM terminal 2T)

Do the PIDs indicate the correct values under 
trouble condition?
(See01-40-6 PCM INSPECTION[L3 WITH TC].)

Yes

Go to the next step.

No

Inspect and repair or replace suspected parts and the 
related harnesses.
If the malfunction remains, perform the intermittent 
concern troubleshooting procedure.
(See01-03-76 INTERMITTENT CONCERN 
TROUBLESHOOTING[L3 WITH TC].)

6

Perform the EGR system operation inspection.
(See01-03-78 ENGINE CONTROL SYSTEM 
OPERATION INSPECTION[L3 WITH TC].)
Does the EGR system operate properly?

Yes

Go to the next step.

No

Inspect or replace the malfunctioning parts, according 
to the inspection results.

7

Perform the TP sweep inspection.
(See01-03-78 ENGINE CONTROL SYSTEM 
OPERATION INSPECTION[L3 WITH TC].)
Does the electronic throttle control system work 
properly?

Yes

Visually inspect the throttle body (damaged/
scratching.) If normal, go to the next step.

No

Inspect or replace the malfunctioning parts, according 
to the inspection results.

8

Perform the Purge Control System Operation 
inspection.
(See01-03-78 ENGINE CONTROL SYSTEM 
OPERATION INSPECTION[L3 WITH TC].)
Does the purge solenoid valve work properly?

Yes

Go to the next step.

No

Inspect or replace the malfunctioning parts, according 
to the inspection results.

9

Perform the A/C Cut-off Operation Inspection.
(See01-03-78 ENGINE CONTROL SYSTEM 
OPERATION INSPECTION[L3 WITH TC].)
Does the A/C Cut-off Operation work properly?

Yes

Go to the next step.

No

Repair or replace the malfunctioning parts according to 
inspection results.

10

Inspect adjustment of TR switch.
(See05-17-11 TRANSAXLE RANGE (TR) 
SWITCH INSPECTION[AW6A-EL, AW6AX-EL].)
Is TR switch adjusted properly?

Yes

Go to the next step.

No

Perform N position leaning.
(See .)
If problem remains replace TR switch.
(See05-17-25 TCM REMOVAL/INSTALLATION[AW6A-
EL, AW6AX-EL].)

11

Access and monitor the FUEL_PRES PID.
Is the FUEL_PRES PID value within the 
specification?
(See01-40-6 PCM INSPECTION[L3 WITH TC].)

Yes

Go to Step 15.

No

Go to the next step.

12

Is the vehicle accelerate performance normally?

Yes

Go to the next step.

No

Go to Step 15.

STEP

INSPECTION

RESULTS

ACTION

1871-1U-06B(01-03).fm  40 ページ  2006年3月15日 水曜日 午前10時36分

 

 

 

 

 

 

 

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