Mazda CX-9 Grand Touring. Manual — part 245

DIAGNOSTIC PROCEDURE

DTC P0172, P0175 (MZI-3.7) DIAGNOSTIC PROCEDURE

POSSIBLE CAUSE



Fuel rail pressure sensor bias



Purge solenoid valve is leaking when the canister is full

Base engine:



Engine oil contamination

Intake Air System:



Damaged or contaminated MAF sensor

STEP

INSPECTION

ACTION

1

VERIFY FREEZE FRAME DATA HAS BEEN
RECORDED



Has FREEZE FRAME DATA been
recorded?

Yes Go to the next step.

No

Record FREEZE FRAME DATA on the

repair order, then go to the next step.

2

VERIFY RELATED REPAIR INFORMATION
AVAILABILITY



Verify related Service Bulletins and/or on-
line repair information availability.



Is any related Service Bulletins available?

Yes

Perform repair or diagnosis according to
the available Service Bulletins.



If the vehicle is not repaired, go to
the next step.

No

Go to the next step.

3

VERIFY RELATED PENDING CODE OR
STORED DTCS



Turn the ignition switch off then to the ON
position (Engine off).



Verify related PENDING CODE or stored
DTCs.



Are any DTCs present other than the
following:



P0172, P0175, P2196 or P2198?

Yes

Go to the appropriate DTC
troubleshooting procedures. (See DTC
TABLE [MZI-3.7].)

No

Go to the next step.

4

INSPECT ENTIRE INTAKE AIR SYSTEM
FOR DEBRIS, BLOCKAGE OR OTHER
DAMAGE



Check the intake air system for obstructions,
restrictions, and damage.

Yes

Repair if necessary.
Then go to Step 9.

2008 Mazda CX-9 Grand Touring

2008 ENGINE PERFORMANCE On-Board Diagnostic (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:08:35 AM

Page 113

© 2005 Mitchell Repair Information Company, LLC.



Check the throttle plate for obstructions or
sludge.



Check the air filter element and housing for
blockage.



Is a concern present?

No

Go to the next step.

5

INSPECT FUEL PRESSURE



Remove the jumper wire(s).



Connect the HO2S connector.



Relieve the fuel pressure.



Connect the mechanical fuel pressure gauge



Pressurize the fuel system.



Turn the ignition switch to the ON position
(Engine running)



Allow the fuel pressure to stabilize.



Turn the ignition switch off.



Turn the ignition switch to the ON position
(Engine running)



Access the PCM and control the FP PID.



Run the fuel pump to obtain maximum fuel
pressure.



Is the fuel pressure within the range for the
vehicle being diagnosed?

WARNING:



Fuel line spills and leakage are dangerous.
Fuel can ignite and cause serious injuries
or death. Fuel can also irritate skin and
eyes. To prevent this, always complete the
"BEFORE REPAIR PROCEDURE".

NOTE:



For vehicle specific fuel pressure ranges,
refer to the "FUEL LINE PRESSURE
INSPECTION ".

Yes Go to the next step.

No

Replace the fuel pump unit. Then go to

Step 9.

6

INSPECT FUEL INJECTOR OPERATION



Remove fuel injector.



Inspect the injector operation.



Is the fuel injector normal?

Yes Go to the next step.

No

Replace the fuel injector.

Then go to Step 9.

INSPECT HO2S OUTPUT VOLTAGE

2008 Mazda CX-9 Grand Touring

2008 ENGINE PERFORMANCE On-Board Diagnostic (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:08:36 AM

Page 114

© 2005 Mitchell Repair Information Company, LLC.

7



Visually inspect the HO2S circuit for
exposed wiring, contamination, corrosion and
correct assembly. Repair if necessary.



Measure the voltage between HO2S terminal
B and D on the component side.



Increase the engine speed to 2,000 rpm for 3
min.



Turn the ignition switch to the ON position
(Engine running)



Monitor the signal voltage.



Is the voltage more than 0.5 V at any time
during the engine running?

Yes Go to the next step.

No

Replace the HO2S.

Then go to Step 9.

8

PERFORM THOROUGH WIGGLE TEST ON
HO2S WIRING HARNESS



Turn the ignition switch off.



Connect the HO2S connector.



Turn the ignition switch to the ON position
(Engine running)



Verify that the engine is at normal operating
temperature.



Access the PCM and monitor the HO2S
signal PID.



Wiggle, shake, and bend small sections of the
wiring harness while working from the
sensor to the PCM.



While monitoring the HO2S PID, does the
HO2S stop switching?

Yes

Isolate the concern and repair if
necessary.
Then go to the next step.

No

Go to the next step.

9

VERIFY TROUBLESHOOTING OF DTC
P0172, P0175 HAS BEEN COMPLETED



Verify that all disconnected connectors are
reconnected.



Turn the ignition switch to the ON position
(Engine off).



Clear the DTC from the PCM memory using
the M-MDS.



Start the engine and run it at idle.



Retrieve DTCs using the M-MDS.



Is the PENDING CODE for this DTC
present?

Yes

Replace the PCM, then go to the next
step. (See PCM
REMOVAL/INSTALLATION [MZI-
3.7] .)

No

Go to the next step.

VERIFY AFTER REPAIR PROCEDURE

2008 Mazda CX-9 Grand Touring

2008 ENGINE PERFORMANCE On-Board Diagnostic (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:08:36 AM

Page 115

© 2005 Mitchell Repair Information Company, LLC.

DTC P0201 [MZI-3.7]

DTC P0201 (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES

10



Perform "AFTER REPAIR PROCEDURE".
(See AFTER REPAIR PROCEDURE
[MZI-3.7].)



Are any DTC present?

Yes

Go to the applicable DTC inspection.
(See DTC TABLE [MZI-3.7].)

No

Troubleshooting completed.

DTC P0201

Injector circuit/open-cylinder No.1

DETECTION

CONDITION



The CCM monitors the operation of the fuel injector drivers in the PCM. The test
fails if the fuel injector circuitry is inoperative.

POSSIBLE CAUSE



Fuel injector No.1 malfunction



Connector or terminal malfunction



Open circuit between fuel pump relay and fuel injector No.1 terminal B



Open circuit between fuel injector No.1 terminal A and PCM terminal 2BJ

2008 Mazda CX-9 Grand Touring

2008 ENGINE PERFORMANCE On-Board Diagnostic (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:08:36 AM

Page 116

© 2005 Mitchell Repair Information Company, LLC.