Mazda CX-9 Grand Touring. Manual — part 216

6. Install in the reverse order of removal.

Tightening torque

8.9-10.5 N.m {90.8-107.0 kgf.cm, 78.8-92.9 in.lbf}

Fig. 39: Removing CHT Sensor Connector
Courtesy of MAZDA MOTORS CORP.

CYLINDER HEAD TEMPERATURE (CHT) SENSOR INSPECTION [MZI-3.7]

RESISTANCE INSPECTION

1. Disconnect the CHT sensor connector.

2. Measure the resistance between the CHT sensor terminals.



If it is not within the specification, replace the CHT sensor.



If the monitor item status/specification (reference) is not within the specification, even though the
resistance is within the specification, perform the "Circuit Open/Short Inspection".

Measure the cylinder head temperature sensor resistance (approx.).

RESISTANCE SPECIFICATION CHART

Cylinder head temperature sensor characteristics graph (reference)

NOTE:



Before performing the following inspection, make sure to follow the
procedure as indicated in the troubleshooting flowchart. (See HOW TO
USE THIS MANUAL .)

Cylinder head temperature (°C {°F}) Resistance (kilohm)

20 {68}

37.387

80 {176}

3.775

2008 Mazda CX-9 Grand Touring

2008 ENGINE Control System (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:07:19 AM

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Fig. 40: Temperature Vs Resistance Graph
Courtesy of MAZDA MOTORS CORP.

CIRCUIT OPEN/SHORT INSPECTION

Fig. 41: Identifying CHT Sensor Wiring Harness-Side Connector And PCM Wiring Harness Side
Connector
Courtesy of MAZDA MOTORS CORP.

1. Disconnect the PCM connector. (See PCM REMOVAL/INSTALLATION [MZI-3.7].)

2008 Mazda CX-9 Grand Touring

2008 ENGINE Control System (MZI-3.7) - Mazda CX-9

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Sunday, November 15, 2009 10:07:19 AM

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© 2005 Mitchell Repair Information Company, LLC.

2. Inspect the following wiring harnesses for open or short. (Continuity inspection)

Open circuit



If there is no continuity, the circuit is open. Repair or replace the wiring harness.



CHT sensor terminal A and PCM terminal 2AL



CHT sensor terminal B and PCM terminal 2AN

Short circuit



If there is continuity, the circuit is shorted. Repair or replace the wiring harness.



CHT sensor terminal A and power supply



CHT sensor terminal A and body ground



CHT sensor terminal B and power supply

FUEL TANK PRESSURE SENSOR INSPECTION [MZI-3.7]

VOLTAGE INSPECTION

1. Remove the evaporative hose component. (See FUEL TANK REMOVAL/INSTALLATION [MZI-

3.7] .)

2. Turn the ignition switch to the ON position.

3. Plug one end of the evaporative hose component and verify that the output voltage from the fuel tank

pressure sensor changes when pressure is applied from the other hose end.



If it cannot be verified even though the related harnesses have no malfunction, replace the
evaporative hose component.(See FUEL TANK REMOVAL/INSTALLATION [MZI-3.7] .)



If the monitor item status/specification (reference) is not within the specification, even though the
resistance is within the specification, perform the "Circuit Open/Short Inspection".

CIRCUIT OPEN/SHORT INSPECTION

2008 Mazda CX-9 Grand Touring

2008 ENGINE Control System (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:07:19 AM

Page 45

© 2005 Mitchell Repair Information Company, LLC.

Fig. 42: Identifying Fuel Tank Pressure Sensor Wiring Harness Side Connector
Courtesy of MAZDA MOTORS CORP.

1. Disconnect the PCM connector. (See PCM REMOVAL/INSTALLATION [MZI-3.7].)

2. Disconnect the fuel tank pressure sensor connector.

3. Inspect the following wiring harnesses for open or short. (Continuity inspection)

Open circuit



If there is no continuity, the circuit is open. Repair or replace the wiring harness.



Fuel tank pressure sensor terminal A and PCM terminal 1AB



Fuel tank pressure sensor terminal B and PCM terminal 1AL



Fuel tank pressure sensor terminal C and PCM terminal 1U

Short circuit



If there is continuity, the circuit is shorted. Repair or replace the wiring harness.



Fuel tank pressure sensor terminal A and power supply



Fuel tank pressure sensor terminal A and body ground



Fuel tank pressure sensor terminal B and power supply



Fuel tank pressure sensor terminal C and body ground

2008 Mazda CX-9 Grand Touring

2008 ENGINE Control System (MZI-3.7) - Mazda CX-9

Microsoft

Sunday, November 15, 2009 10:07:19 AM

Page 46

© 2005 Mitchell Repair Information Company, LLC.