Mazda CX-9 Grand Touring. Manual — part 338

NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE (MZI-3.7) DIAGNOSTIC PROCEDURE

STEP

INSPECTION

RESULTS

ACTION

1

Verify the following:



Vacuum connection



Restriction in intake-air system (such
as air cleaner element, fresh air duct)



No air leakage from intake-air system



No restriction of intake-air system



Proper sealing of intake manifold and
components attached to intake
manifold



Fuel quality (such as proper octane,
contamination, winter/summer blend)

Are all items normal?

Yes

Go to the next step.

No

Service if necessary.

Repeat Step 1.

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 the appropriate DTC inspection.
(See DTC TABLE [MZI-3.7] .)

No

No DTC is displayed:

Go to the next step.

3

Is the engine overheating?

Yes

Go to symptom troubleshooting "No. 17
Cooling system concerns-Overheating".

No

Go to the next step.

4

Connect the M-MDS to the DLC-2.
Access APP1, APP2, APP3, RPM, MAF,
TP1, TP2, IAT and VSS PIDs.
Drive vehicle while monitoring PIDs.
Are PIDs within specifications?
(See PCM INSPECTION [MZI-3.7] .)

Yes

Go to the next step.

No

APP1, APP2, APP3 PIDs:

Inspect if output signal accelerator pedal

position sensor changes smoothly.

RPM PID:

Inspect CKP sensor and related wiring

harness for vibration or intermittent

open/short circuit or both.

MAF PID:

Inspect for intermittent open circuit of

MAF sensor and related wiring harness.

TP1, TP2 PID:

Inspect if output signal TP sensor changes

smoothly.

IAT PID:

Inspect for air suction in intake-air

system.

If normal, inspect intermittent short circuit

of IAT sensor and related wiring

harnesses.

2008 Mazda CX-9 Grand Touring

2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:10:05 AM

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VSS PID:

Inspect for intermittent open circuit of

VSS and related wiring harness.

5

Visually inspect the CKP sensor and teeth
of crankshaft pulley.
Are the CKP sensor and teeth of crankshaft
pulley normal?

Yes

Go to the next step.

No

Replace the malfunctioning part.

6

Inspect the spark plug condition.
Is spark plug wet, covered with carbon or
grayish white?

Yes

Spark plug is wet or covered with
carbon:
Inspect the fuel injector for fuel leakage.
Inspect spark plug and high-tension lead.
Spark plug is grayish white:
Inspect the fuel injector for clogging.

No

Install the spark plugs on original

cylinders.

Go to the next step.

7

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

Yes

Go to the next step.

No

Replace PCV valve.

8

Perform electronic throttle control system
operation inspection.
(See ENGINE CONTROL SYSTEM
OPERATION INSPECTION [MZI-3.7].)
Does electronic throttle control system
function properly?

Yes

Go to the next step.

No

Repair or replace the malfunctioning part

according to electronic throttle control

system operation inspection results.

9

visually inspect deformed exhaust system
part.
Is there any deformed exhaust system part?

Yes

Replace the suspected part.

No

Go to the next step.

10

Install the fuel pressure gauge between the
fuel pipe and the fuel distributor.
Short check connector terminal F/P to body
GND using a jumper wiring.
Turn the ignition switch to the ON position.
Is fuel line pressure correct with ignition
switch to ON position?
(See FUEL LINE PRESSURE
INSPECTION [MZI-3.7] .)

Yes

Go to the next step.

No

Zero or low:

Inspect the fuel pump relay and fuel pump

circuit.

Inspect the fuel line for clogging.

If there is no malfunction, replace the fuel

pump unit.

(See FUEL PUMP UNIT

REMOVAL/INSTALLATION [MZI-

3.7] .)
High:

Replace the fuel pump unit.

(See FUEL PUMP UNIT

REMOVAL/INSTALLATION [MZI-

3.7] .)

NOTE:



The following test is for engine
stalling with the A/C on concern. If

Yes

Go to the next step.

If A/C is always on, go to symptom

troubleshooting "No.24 A/C is always on

or A/C compressor runs continuously".

2008 Mazda CX-9 Grand Touring

2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:10:05 AM

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© 2005 Mitchell Repair Information Company, LLC.

11

Connect pressure gauge to the A/C low and
high side pressure lines.Turn the A/C on
and measure low side and high side
pressures.Are pressures within
specifications?(See REFRIGERANT
PRESSURE CHECK .)

other symptoms exist, go to the
next step.

No

(See NO.24 A/C IS ALWAYS ON OR

A/C COMPRESSOR RUNS

CONTINUOUSLY [MZI-3.7].)

For other symptoms, inspect the

following:



Refrigerant charging amount



Condenser fan operation

12

Inspect for A/C cut-off operation.
(See ENGINE CONTROL SYSTEM
OPERATION INSPECTION [MZI-3.7].)
Does the A/C cut-off function properly?

Yes

Go to the next step.

No

Inspect A/C cut-off system components.

13

Disconnect the vacuum hose between the
purge solenoid valve and the intake
manifold from purge solenoid valve side.
Plug opening end of vacuum hose.
Drive the vehicle.
Does the engine condition improve?

Yes

Inspect if purge solenoid valve is stuck
open mechanically.
Inspect the evaporative emission control
system.
(See ENGINE CONTROL SYSTEM
OPERATION INSPECTION [MZI-
3.7].)

No

Go to the next step.

14

Visually inspect the CMP sensor and
projections of camshaft pulley.
Are the CMP sensor and projections of
camshaft pulley normal?

Yes

Go to the next step.

No

Replace the malfunctioning part.

15

Inspect the variable valve timing control
system operation.
(See ENGINE CONTROL SYSTEM
OPERATION INSPECTION [MZI-3.7].)
Does the variable valve timing control
system function properly?

Yes

Go to the next step.

No

Repair or replace the malfunctioning part

according to variable valve timing control

system inspection results.

16

Is the engine compression correct?

Yes

Inspect the following:



Valve timing



Internal transaxle components



Brake system for dragging

No

Inspect for cause.

17



Verify test results.



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

(See SYMPTOM DIAGNOSTIC INDEX [MZI-3.7].)



If malfunction remains, inspect related Service Bulletins and/or On-line Repair
Information and perform repair or diagnosis.

2008 Mazda CX-9 Grand Touring

2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:10:05 AM

Page 60

© 2005 Mitchell Repair Information Company, LLC.

NO.13 KNOCKING/PINGING-ACCELERATION/CRUISE [MZI-3.7]

NO.13 KNOCKING/PINGING-ACCELERATION/CRUISE (MZI-3.7) DETECTION CONDITIONS
AND POSSIBLE CAUSES



If vehicle is repaired, troubleshooting completed.



If vehicle is not repaired or additional diagnostic information is not available,
replace the PCM.

(See PCM REMOVAL/INSTALLATION [MZI-3.7] .)

13

KNOCKING/PINGING - ACCELERATION/CRUISE

DESCRIPTION

Sound is heard when air/fuel mixture is ignited by something other than spark plug
(such as hot spot in combustion chamber).

POSSIBLE

CAUSE



Engine overheating due to cooling system malfunction



CHT sensor malfunction



IAT sensor malfunction



MAF sensor malfunction



Knock sensor malfunction



Erratic signal from CMP sensor



Inadequate engine compression



Inadequate fuel pressure

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 SERVICE
PRECAUTION" and "AFTER SERVICE PRECAUTION" described in this
manual.

(See BEFORE SERVICE PRECAUTION [MZI-3.7] .)

(See AFTER SERVICE PRECAUTION [MZI-3.7] .)

CAUTION:



Disconnecting/connecting quick release connector without cleaning it
may cause damage to fuel pipe and quick release connector. Always
clean quick release connector joint area before
disconnecting/connecting, and make sure that it is free of foreign

2008 Mazda CX-9 Grand Touring

2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:10:05 AM

Page 61

© 2005 Mitchell Repair Information Company, LLC.