Mazda CX 7. Manual - part 84

SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–33

01-03

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 DTC is displayed:
Go to the next step.

Access the ECT PID.
Start and warm-up engine to normal operating
temperature.
Is the ECT PID readingbelow 82

°C {180°F}?

Yes

Go to the next step.

Go to symptom troubleshooting “NO.18 COOLING
SYSTEM CONCERNS, RUNS COLD”.
(See01-03-61 NO.18 COOLING SYSTEM
CONCERNS-RUNS COLD[L3 WITH TC].)

Verify the cooling fan operation. Does the
cooling fan operate properly according ECT PID
value?

Yes

Go to the next step.

Perform the Cooling Fan Control System Operation
Inspection.
(See01-03-78 ENGINE CONTROL SYSTEM
OPERATION INSPECTION[L3 WITH TC].)

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.

Go to the next step.

Access and monitor following the PIDs using the
data monitor function.

• ECT

• APP

• MAF

• 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.

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].)

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 11.

Go to the next step.

Is the vehicle accelerate performance normally?

Yes

Go to the next step.

Go to Step 10.

Inspect the fuel pressure sensor.
(See01-40-35 FUEL PRESSURE SENSOR
INSPECTION[L3 WITH TC].)
Is the fuel pressure sensor normal?

Yes

Go to Step 11.

Replace the delivery pipe.

Replace the high pressure fuel pump.
Monitor FUEL_PRES PID.
Is the FUEL_PRES PID value within the
specified?
(See01-40-6 PCM INSPECTION[L3 WITH TC].)

Yes

Troubleshooting is completed.
Go to Step 13.

Go to the next step.

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.

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

Remove the thermostat and inspection
operation.
(See01-12-11 THERMOSTAT REMOVAL/
INSTALLATION[L3 WITH TC].)
(See01-12-11 THERMOSTAT INSPECTION[L3
WITH TC].)
Is the thermostat normal?

Yes

Inspect and repair or replace the throttle body.
If throttle body is normal or the problem remains,
replace the injector driver module.

Replace thermostat.

STEP

INSPECTION

RESULTS

ACTION

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SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–34

End Of Sie

NO.8 ENGINE RUNS ROUGH/ROLLING IDLE[L3 WITH TC]

id010339801400

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.

STEP

INSPECTION

RESULTS

ACTION

ENGINE RUNS ROUGH/ROLLING IDLE

DESCRIPTION

• Engine speed fluctuates between the specified idle speed and lower speed and, engine shakes

excessively.

• Idle speed is too slow and the engine shakes excessively.

POSSIBLE CAUSE

• Air leakage from intake-air system

• A/C system improper operation

• Erratic signal to ignition coil

• Spark plug malfunction

• Purge solenoid valve malfunction

• Improper operation of electronic throttle control system

• EGR valve malfunction

• Low engine compression or excessive unbalance for each cylinder

• Improper valve timing

• Improper variable valve timing control system

• Poor fuel quality

• PCV valve malfunction

• Intake-air system restriction

• Exhaust system or three-way catalytic converter (TWC) restriction or clogging

• Disconnected electrical connectors

• Inadequate fuel pressure (high or low pressure side)

• Fuel pressure sensor or related circuit malfunction

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

• Relief valve malfunction (built-in delivery pipe)

• Fuel pump (low-side) body mechanical malfunction

• Fuel filter restriction or clogging

• Fuel leakage

• Incorrect fuel injection timing

• Unbalanced fuel injection amount for each cylinder

• High pressure fuel pump malfunction

• Fuel injector malfunction

• Erratic signal from CKP sensor

• Erratic or no signal from CMP sensor

• ECT sensor or related circuit malfunction

• Manifold absolute pressure (MAP) sensor or related circuit malfunction

• Accelerator position sensor or related circuit malfunction

• MAF sensor malfunction

• Incorrect or no load signal input

• Engine overheating

• Vacuum leakage

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]

01-03–35

01-03

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION

Inspect for the following:

• Fuel quality (proper octane, contamination,

winter/summer blend)

• Intake-air system restriction or leakage

• Electrical connectors connection

• Fuel leakage in fuel system

• Vacuum leakage

Are all items normal?

Yes

Go to the next step.

Service if necessary.
Repeat Step 1.

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 DTC is displayed:
Go to the next step.

Access the ECT PID.
Verify that the ECT PID isless than 116

°C

{241

°F} during driving.

Is the ECT PID less than specified?

Yes

Go to the next step.

The cause of this concern could be from the cooling
system overheating.
Perform the symptom troubleshooting “NO.17
COOLING SYSTEM CONCERNS - OVERHEATING.”
(See01-03-60 NO.17 COOLING SYSTEM
CONCERNS-OVERHEATING[L3 WITH TC].)

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.

Repair or replace the malfunctioning parts according to
inspection results.

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.

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

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.

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

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.

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

Perform the Variable Valve Timing Control
System Operation Inspection.
(See01-03-78 ENGINE CONTROL SYSTEM
OPERATION INSPECTION[L3 WITH TC].)
Does the variable valve timing control system
work properly?

Yes

Go to the next step.

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

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 to
the inspection results.

Go to the next step.

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SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–36

End Of Sie

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

• ACSW

• APP

• ECT

• MAF

• MAP

• 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.

Inspect for restriction in the exhaust system and
three-way catalytic converter (TWC).
Is there any restriction?

Yes

Replace the malfunctioning part.

Go to the next step.

Remove and shake the PCV valve.
Does the PCV valve rattle?

Yes

Go to the next step.

Replace the PCV valve.

Perform the spark test.
(See01-03-78 ENGINE CONTROL SYSTEM
OPERATION INSPECTION[L3 WITH TC].)
Is a strong blue spark visible at each cylinder?

Yes

Go to the next step.

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

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 18.

Go to the next step.

Is the vehicle accelerate performance normally?

Yes

Go to the next step.

Go to Step 17.

Inspect the fuel pressure sensor.
(See01-40-35 FUEL PRESSURE SENSOR
INSPECTION[L3 WITH TC].)
Is the fuel pressure sensor normal?

Yes

Go to Step 18.

Replace the delivery pipe.

Replace the high pressure fuel pump.
Monitor FUEL_PRES PID.
Is the FUEL_PRES PID value within the
specified?
(See01-40-6 PCM INSPECTION[L3 WITH TC].)

Yes

Troubleshooting is completed.
Go to Step 21.

Go to the next step.

Connect the fuel pressure gauge between the
fuel pump and the high pressure fuel pump.
Measure the fuel pressure line of the low
pressure side.
(See01-14-5 FUEL LINE PRESSURE
INSPECTION[L3 WITH TC].)
Is the fuel pressure within the specification?

Yes

Go to the next step.

Inspect for the following:

• Fuel line restriction

• Fuel filter clogging

If normal replace the fuel pump.

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

Yes

Go to the next step.

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

Measure the compression pressure for each
cylinder.
(See01-10-9 COMPRESSION INSPECTION[L3
WITH TC].)
Are compression pressures within the
specification?

Yes

Replace the injector driver module.
If the problem remains, overhaul the engine.

Inspect for the following:

• Damaged valve seat

• Worn valve stem and valve guide

• Worn or stuck piston ring

• Worn piston, piston ring or cylinder

• Improper valve timing

Service if necessary.

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.

STEP

INSPECTION

RESULTS

ACTION

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