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

Page 43 

© 2005 Mitchell Repair Information Company, LLC. 

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

  

Microsoft 

 

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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.