Mazda CX-9 Grand Touring. Manual — part 271

DTC P0453 [MZI-3.7]

DTC P0453 (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES

6



Perform the fuel tank pressure sensor
inspection. (See FUEL TANK
PRESSURE SENSOR
INSPECTION [MZI-3.7] .)



Is the fuel tank pressure sensor
normal?

No

Replace the evaporative hose component, then go

to the next step. (See FUEL TANK

REMOVAL/INSTALLATION [MZI-3.7] .)

7

VERIFY TROUBLESHOOTING OF
DTC P0452 COMPLETED



Make sure to reconnect all
disconnected connectors.



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



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



Start the engine and warm it up
completely.



Is same 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.

8

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

Troubleshooting completed.

DTC P0453

Fuel tank pressure sensor high 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
jumps above a minimum allowable calibrated parameter.

POSSIBLE

CAUSE



Fuel tank pressure sensor malfunction



Connector or terminal malfunction



Open circuit between fuel tank pressure sensor terminal A and PCM terminal 1AB



Open circuit between fuel tank pressure sensor terminal B and PCM terminal 1AL



Short to the constant voltage supply circuit between fuel tank pressure sensor
terminal A and PCM terminal 1AB



Short to power supply between fuel tank pressure sensor terminal C and PCM
terminal 1U



Fuel tank pressure sensor power circuit and signal circuit are shorted 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 217

© 2005 Mitchell Repair Information Company, LLC.

DIAGNOSTIC PROCEDURE

DTC P0453 (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

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

Page 218

© 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 TANK PRESSURE
SENSOR CONNECTION FOR POOR
CONNECTION



Turn the ignition switch off.



Disconnect 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
9.

No

Go to the next step.

4

VERIFY FUEL TANK PRESSURE
SENSOR SIGNAL CIRCUIT FOR
SHORT TO POWER SUPPLY



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



Measure the voltage between the
following terminals:



Fuel tank pressure sensor
terminal A (wiring harness-
side) and body ground.



Fuel tank pressure sensor
terminal C (wiring harness-
side) and body ground.



Are there voltage B+?

Yes

Repair or replace suspected part, then go to Step
9.

No

Go to the next step.

5

INSPECT PCM CONNECTOR FOR
POOR CONNECTION



Turn the ignition switch off.



Disconnect the fuel tank pressure
sensor and PCM connector.



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



Is there any malfunction?

Yes

Repair or replace suspected part, then go to Step
9.

No

Go to the next step.

VERIFY FUEL TANK PRESSURE
SENSOR CIRCUIT FOR OPEN

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 219

© 2005 Mitchell Repair Information Company, LLC.

6

CIRCUIT



Inspect for continuity between the
following circuits:



Fuel tank pressure sensor
connector terminal A (harness-
side) and PCM connector
terminal 1AB.



Fuel tank pressure sensor
connector terminal B (harness-
side) and PCM connector
terminal 1AL



Are there continuity?

Yes Go to the next step.

No

Repair or replace suspected part, then go to Step

9.

7

INSPECT FUEL TANK PRESSURE
SENSOR SIGNAL CIRCUIT AND
POWER CIRCUIT FOR SHORT EACH
OTHER



Turn the ignition switch off.



Disconnect the fuel tank pressure
sensor and PCM connector.



Measure resistance between PCM
connector terminal 1U (harness-side)
and CM connector terminal 1AB
(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

9.

8

INSPECT FUEL TANK PRESSURE
SENSOR



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



Is the fuel tank pressure sensor
normal?

Yes Go to the next step.

No

Replace the evaporative hose component, then go

to the next step. (See FUEL TANK

REMOVAL/INSTALLATION [MZI-3.7] .)

9

VERIFY TROUBLESHOOTING OF
DTC P0453 COMPLETED



Make sure to reconnect all
disconnected connectors.



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



Clear the DTC from the PCM

Yes

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

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 220

© 2005 Mitchell Repair Information Company, LLC.