Mazda CX-9 Grand Touring. Manual — part 270



Is other DTCs present?

4

CLEAR AND ATTEMPT TO
RETRIEVE THE DTC



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



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



Run the engine for approx. 10 s .



Check for continuous memory
DTCs.



Is the same DTC present?

Yes Go to the next step.

No

DTC troubleshooting completed.

5

INSPECT FUEL TANK PRESSURE
AND PCM SENSOR CONNECTOR
FOR POOR CONNECTION



Turn the ignition switch off.



Disconnect the MAF/IAT sensor
connector.



Inspect for poor connection (such as
damaged/pulled-out pins, corrosion).



Are there any malfunction?

Yes Repair or replace suspected part, then go to Step 8.

No

Go to the next step.

6

INSPECT THE FUEL TANK
PRESSURE



Inspect the MAF sensor. (See FUEL
TANK PRESSURE SENSOR
INSPECTION [MZI-3.7] .)



Is there malfunction?

Yes

Replace evaporative hose component, then go to
Step 8. (See FUEL TANK
REMOVAL/INSTALLATION [MZI-3.7] .)

No

Go to the next step.

7

INSPECT FOR CORRECT PCM
OPERATION



Disconnect all the PCM connectors.



Visually inspect for:



Pushed out pins



Corrosion



Connect all the PCM connectors and
verify that they seat correctly.



Retrieve DTCs using the M-MDS.



Is the PENDING CODE for this
DTC present?

Yes Go to the next step.

No

The system is correctly. Go to the next step.

VERIFY TROUBLESHOOTING OF

2008 Mazda CX-9 Grand Touring

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

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Sunday, November 15, 2009 10:08:38 AM

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DTC P0452 [MZI-3.7]

DTC P0452 (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES

8

DTC P0451 COMPLETED



Verify that all disconnected
connectors are reconnected.



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



Perform the "KOEO or KOER self-
test" using the M-MDS. (See
KOEO/KOER SELF TEST [MZI-
3.7].)



Start the engine and wait for
approx. 10s.



Is the PENDING CODE for the
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.

9

VERIFY AFTER REPAIR
PROCEDURE



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



Are any DTCs present?

Yes

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

No

DTC troubleshooting completed.

DTC P0452

Fuel tank pressure sensor low input

DETECTION

CONDITION



The PCM monitors the evaporative emission (EVAP) control system fuel tank
pressure sensor input signal to the PCM. The test fails when the signal average drops
below a minimum allowable calibrated parameter.

POSSIBLE

CAUSE



Fuel tank pressure sensor malfunction



Connector or terminal malfunction



Short to ground between fuel tank pressure sensor terminal A and PCM terminal 1
AB



Fuel tank pressure sensor signal circuit and ground circuit for short each other

2008 Mazda CX-9 Grand Touring

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

Microsoft

Sunday, November 15, 2009 10:08:38 AM

Page 214

© 2005 Mitchell Repair Information Company, LLC.

DIAGNOSTIC PROCEDURE

DTC P0452 (MZI-3.7) DIAGNOSTIC PROCEDURE

STEP

INSPECTION

ACTION

1

VERIFY FREEZE FRAME DATA HAS
BEEN RECORDED



Has the 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.

VERIFY RELATED REPAIR

2008 Mazda CX-9 Grand Touring

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

Microsoft

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© 2005 Mitchell Repair Information Company, LLC.

2

INFORMATION AVAILABILITY



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



Is any related repair information
available?

Yes

Perform the repair or diagnosis according to the
available repair information.



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

No

Go to the next step.

3

INSPECT FUEL TANKE PRESSURE
SENSOR CONNECTOR FOR POOR
CONNECTION



Turn the ignition switch off.



Disconnect the fuel tank pressure
sensor connector.



Inspect for poor connection (such as
damaged/pulled-out pins, corrosion).



Are there any malfunction?

Yes

Repair or replace suspected part, then go to Step
7.

No

Go to the next step.

4

VERIFY FUEL TANK PRESSURE
SIGNAL CIRCUIT FOR SHORT TO
GROUND



Turn the ignition switch off.



Inspect for continuity between fuel
tank pressure sensor terminal A
(wiring harness-side) and body
ground.



Is there continuity?

Yes

Repair or replace suspected part, then go to Step
7.

No

Go to the next step.

5

INSPECT FUEL TANKE PRESSURE
SENSOR SIGNAL CIRCUIT AND
GROUND CIRCUIT FOR SHORT
EACH OTHER



Turn the ignition switch off.



Disconnect the fuel tank pressure
sensor and PCM connector.



Measure resistance between PCM
terminal 1AB (wiring harness-side)
and PCM terminal 1AL (wiring
harness-side)



Is the resistance more than 10
kilohms?

Yes Go to the next step.

No

Repair or replace suspected part, then go to Step

7.

INSPECT FUEL TANKE PRESSURE
SENSOR

Yes Go to the next step.

2008 Mazda CX-9 Grand Touring

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

Microsoft

Sunday, November 15, 2009 10:08:38 AM

Page 216

© 2005 Mitchell Repair Information Company, LLC.