Mazda CX-9 Grand Touring. Manual - part 408

OPERATION TEST 

1. Follow "BEFORE SERVICE PRECAUTION" before performing any work operations to prevent fuel 

from spilling from the fuel system. (See BEFORE SERVICE PRECAUTION [MZI-3.7].)  

2. Remove the fuel-filler cap. (See FUEL TANK REMOVAL/INSTALLATION [MZI-3.7].)  

3. Start the fuel pump using the following procedure:  

Using M-MDS  

1. Connect the M-MDS to the DLC-2.  

2. Turn the ignition switch to the ON position. 

Fig. 32: Connecting M-MDS To DLC-2 
Courtesy of MAZDA MOTORS CORP. 

3. Using the simulation function FP, verify that operation sound is heard from the fuel pump when FP is 

turned from OFF to ON. 



If the operation sound cannot be verified, measure the voltage at fuel pump wiring harness-side 
connector terminal B. 



If as specified, inspect the following: 



Fuel pump continuity  



If not within the specification, inspect the following: 



Fuel pump relay  



Wiring harnesses and connectors between battery-fuel pump relay-fuel pump 

is turned to the ON position.  

NOTE:



To improve start ability, the fuel pump control operates the fuel pump unit 
when the ignition switch is turned to the ON position. Due to this, fuel 
pressure is rapidly increased and fuel control is stabilized.  

 

2008 Mazda CX-9 Grand Touring 

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

  

Microsoft 

 

Sunday, November 15, 2009 10:04:45 AM

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© 2005 Mitchell Repair Information Company, LLC. 

Fig. 33: Identifying Fuel Pump Unit Wiring Harness-Side Connector 
Courtesy of MAZDA MOTORS CORP. 

Standard  

B+ (Ignition switch at ON)  

Without using M-MDS  

1. Disconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-

3.7] .)  

2. Remove the fuel pump relay. 

3. Using a jumper wire, short fuel pump relay terminals C and D in the main fuse block.  

4. Connect the negative battery cable and operate the fuel pump.  

5. Verify that operation sound is heard from the fuel pump when ignition switch turn to the ON 

position. 

Fig. 34: Identifying Main Fuse Block (Fuel Pump Relay) 
Courtesy of MAZDA MOTORS CORP. 



If the operation sound cannot be verified, measure the voltage at fuel pump wiring harness-

CAUTION:



Short the specified terminals because shorting the wrong 
terminal of the main fuse block may cause malfunctions.  

 

2008 Mazda CX-9 Grand Touring 

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

  

Microsoft 

 

Sunday, November 15, 2009 10:04:45 AM

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© 2005 Mitchell Repair Information Company, LLC. 

side connector terminal B. 



If as specified, inspect the following: 



Fuel pump continuity  



If not within the specification, inspect the following: 



Fuel pump relay  



Wiring harnesses and connectors between battery-fuel pump relay-fuel pump  

Standard  

B+ (Ignition switch at ON)  

Fig. 35: Identifying Fuel Pump Unit Wiring Harness-Side Connector 
Courtesy of MAZDA MOTORS CORP. 

6. Disconnect the jumper wire.  

4. Complete the "AFTER SERVICE PRECAUTION". (See AFTER SERVICE PRECAUTION [MZI-

3.7].)  

CONTINUITY INSPECTION 

1. Disconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [MZI-3.7] .)  

2. To remove the service hole cover, remove the following parts: 

1. Second-row seat (See SECOND-ROW SEAT REMOVAL/INSTALLATION .)  

2. Edge cover (See LONG SLIDER REMOVAL/INSTALLATION .)  

3. Long slider cover (See LONG SLIDER REMOVAL/INSTALLATION .)  

4. Rear heat duct No.3 (See REAR HEAT DUCT COMPONENT 

REMOVAL/INSTALLATION .)  

5. Service hole cover (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZI-3.7].)  

3. Disconnect the fuel pump unit connector.  

4. Inspect for continuity between fuel pump unit connector terminals B and D. 



If there is no continuity, replace the fuel pump unit. (See FUEL PUMP UNIT 
REMOVAL/INSTALLATION [MZI-3.7].)  



If as specified carry out the "Circuit Open/Short Inspection". 

 

2008 Mazda CX-9 Grand Touring 

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

  

Microsoft 

 

Sunday, November 15, 2009 10:04:45 AM

Page 28 

© 2005 Mitchell Repair Information Company, LLC. 

Fig. 36: Identifying Fuel Pump Unit Wiring Harness-Side Connector 
Courtesy of MAZDA MOTORS CORP. 

CIRCUIT OPEN/SHORT INSPECTION 

1. Inspect the following wiring harnesses for open or short circuit (continuity check). 

Fig. 37: Identifying Main Fuse Block (Fuel Pump Relay) 
Courtesy of MAZDA MOTORS CORP. 

Fig. 38: Identifying Fuel Pump Unit Wiring Harness-Side Connector 
Courtesy of MAZDA MOTORS CORP. 

Open circuit  



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

 

2008 Mazda CX-9 Grand Touring 

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

  

Microsoft 

 

Sunday, November 15, 2009 10:04:45 AM

Page 29 

© 2005 Mitchell Repair Information Company, LLC.