Mazda CX 7. Manual — part 83

SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–29

01-03

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

Revised 10/2006 (Ref. No. R144/06)

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION

1

Connect the M-MDS to the DLC-2.
Do any of the following conditions appear?

• Engine does not completely start.

• DTC B1681 is displayed.

Yes

Both conditions are appear:
Go to Step 5.

No

Either or other condition appears:
Go to the next step.

2

Does the engine stall after approx. 2s from
when it is started?

Yes

Go to the next step.

No

Is the Is the immobilizer system is normal.
Go to Step 20.

3

Is the coil connector securely connected to coil?

Yes

Go to the next step.

No

Connect the connector securely, retest from Step 1.

4

Does the security light illuminate?

Yes

Go to the next step.

No

Inspect and repair or replace the following:

• Instrument cluster

(See09-22-3 INSTRUMENT CLUSTER
INSPECTION.)

With advanced keyless entry system

• Between keyless CM 3X and instrument cluster 2R

• Between keyless CM 3W and instrument cluster 2T

Without advanced keyless entry system

• Between PCM 1AM and instrument cluster 2R

• Between PCM 1AI and instrument cluster 2T

5

Retrieve the DTC using the M-MDS.
Are any of the following DTCs present?
DTC
B1213, B1342, B1600, B1601, B1602, B1681,
B2103, B2431

Yes

Go to appropriate DTC test.
(See09-02B-3 DTC TABLE[IMMOBILIZER SYSTEM
(ADVANCED KEYLESS SYSTEM)].)

No

Go to the next step.

6

Is there continuity between PCM terminal 1BD,
1AZ, 1BH and ground?

Yes

Go to the next step.

No

Repair or replace the wiring harness.

7

Turn the ignition switch to the ON position
(Engine off.)
Measure the voltage between PCM terminal
1BD, 1AZ, 1BH and ground.
Is the voltage below 1.0V?

Yes

Go to the next step.

No

Repair or replace the wiring harness.

8

Turn the ignition switch to the ON position.
(Engine off)
Access the VPWR PID.
Is the VPWR PID normal?
VPWR PID
Battery voltage

Yes

Go to the next step.

No

Repair or replace the wiring harness.

9

Disconnect the coil connector.
Turn the ignition switch to the ON position.
(Engine off)
Is there battery voltage at coil connector terminal
D?

Yes

Go to the next step.

No

Repair or replace the wiring harness between coil
connector terminal D and the fuse panel.

10

Inspect the following wiring harness and
connectors.

With advanced keyless entry system

• Between coil terminal A and keyless CM

terminal 3U

• Between coil terminal B and keyless CM

terminal 3V

Without advanced keyless entry system

• Between coil terminal A and instrument

cluster 2Q

• Between coil terminal B and instrument

cluster 2S

Is there any malfunction (open or short circuit,
terminal corrosion, etc.)?

Yes

Repair or replace malfunctioning part.

No

With advanced keyless entry system

Go to the next step.

Without advanced keyless entry system

Go to Step 14.

11

Is there continuity between the keyless CM
harness-side connector terminal 2B and body
ground?

Yes

Go to the next step.

No

Repair or replace the wiring harness.

12

Turn the ignition switch to the ON position.
Measure the voltage between keyless CM
harness-side connector terminal 2B and body
ground.
Is the voltage below 1.0V?

Yes

Go to the next step.

No

Repair or replace the wiring harness.

SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–30

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

Revised 10/2006 (Ref. No. R144/06)

13

Turn the ignition switch to the ON position.
(Engine off.)
Measure the voltage between keyless CM
harness-side connector terminal 2A, 2C, 2D and
body ground.
Is the voltage B+?

Yes

Go to the next step.

No

Repair or replace the wiring harness.

14

Inspect the following wiring harnesses and
connectors.

• Between keyless CM terminal 3W and PCM

1AI

• Between keyless CM terminal 3X and PCM

1AM

Is there any malfunction (open or short circuit,
terminal corrosion, etc.)?

Yes

Repair or replace malfunctioning part.

No

Go to the next step.

15

Turn the ignition switch off.
Disconnect the coil connector.
Turn the ignition switch to the ON position.
(Engine off.)
Measure the voltage between coil harness-side
connector terminal D and body ground.
Is the voltage B+?

Yes

Go to the next step.

No

Repair or replace the wiring harness.

16

Inspect for the following:

• Fuel quality (proper octane, contamination,

winter/summer blend)

• Intake-air system leakage and restriction

• Electrical connectors

• Fuses

• Fuel leakage

• Vacuum leakage

• Poor connection for PCM ground and body

ground

Are all items normal?

Yes

Go to the next step.

No

Service if necessary.
Repeat Step 16.

17

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.

18

Access the ECT PID using the M-MDS.
Verify that the ECT PID is less than 116

°C

{241

°F} during driving.

Is the ECT PID less than specified?

Yes

Go to the next step.

No

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].)

19

Does the engine start with throttle close?

Yes

Go to the next step.

No

Go to Step 25.

20

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

Inspect the valve timing.

No

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

21

Will the engine start and run smoothly at part
throttle?

Yes

Go to the next step.

No

Go to Step 23.

22

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
the to inspection results.

23

Access the RPM PID using the M-MDS.
Is the RPM PID indicating engine speed when
the cranking engine.

Yes

Go to the next step.

No

Inspect the CKP sensor for following;

• Installation condition

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

• Damaged trigger wheel and camshaft

• Open or short circuit in wiring harnesses Is there

any malfunction detected?

STEP

INSPECTION

RESULTS

ACTION

SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–31

01-03

24

Inspect CMP sensor for the following;

• Installation condition

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

• Damaged trigger wheel and camshaft

• Open or short circuit in wiring harnesses Is

there any malfunction detected?

Yes

Repair or replace the malfunctioning part according
inspection results.

No

Go to the next step.

25

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

Yes

Go to the next step.

No

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

26

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.

27

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

• ECT

• APP

• MAF

• O2S11

• O2S12

• LONGFT1

• SHTFT1

Do the PIDs indicate the correct values under
the malfunction 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].)

28

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

Yes

Replace malfunctioning part.

No

Go to the next step.

29

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

Yes

Go to the next step.

No

Replace the PCV valve.

30

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.

No

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

31

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 38.

No

Go to the next step.

32

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 37.

No

Go to the next step.

33

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

Yes

Go to the next step.

No

Replace the delivery pipe.

34

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

Yes

Go to the next step.

No

Inspect for the following:

• Fuel line restriction

• Fuel filter clogging

If normal, replace the fuel pump.

35

Inspect the 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.

No

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

STEP

INSPECTION

RESULTS

ACTION

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SYMPTOM TROUBLESHOOTING [L3 WITH TC]

01-03–32

End Of Sie

NO.7 SLOW RETURN TO IDLE[L3 WITH TC]

id010339801300

Diagnostic procedure

36

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

Yes

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

No

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.

37

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

7

SLOW RETURN TO IDLE

DESCRIPTION

• Engine takes more time than normal to return to idle speed.

• Engine speed continues at fast idle after warm-up

POSSIBLE CAUSE

• ECT sensor or related circuit malfunction

• Thermostat is stuck open

• Fuel injection timing is incorrect

• Erratic signal from CKP sensor

• Erratic signal from CMP sensor

• Accelerator position sensor or related circuit malfunction

• Air suction in intake-air system

• MAF sensor or related circuit malfunction

• Fuel pressure sensor or related circuit malfunction

• Excessive fuel pressure

• Relief valve malfunction (built-in delivery pipe)

• Fuel injector malfunction

• Cooling fan control system malfunction

• Improper load signal input

• Injector driver module 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

Inspect air suction in intake-air system
components while racing engine to higher
speed.
Is any air suction?

Yes

Repair or replace as necessary.

No

Go to the next step.

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