Mazda CX-9 Grand Touring. Manual - part 312

2

INFORMATION AVAILABILITY  



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



Is any related Service Bulletins available?  

Yes

available Service Bulletins. 



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

No

Go to the next step.

3

INSPECT ACCELERATOR PEDAL FOR 
OBSTRUCTION  



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



Depress the accelerator pedal fully to the 
floor and release.  



Does the pedal move freely to the floor and 
back?  

Yes Go to the next step.

No

Isolate and repair the obstruction. Then go 

to Step 12.

4

INSPECT APP SENSOR SIGNAL 
VOLTAGE RANGES FOR ACCELERATOR 
PEDAL FULLY APPLIED AND DEPRESS 
POSITIONS  



Access the PCM and monitor the APP1, 
APP2 and APP3 PIDs.  



Verify the following values of the PIDs 
when depressing the accelerator pedal fully 
to the floor. 



APP1: 0.48-1.79 V  



APP2: 2.95-4.62 V  



APP3: 2.43-4.02 V  



Verify the following values of the PIDs 
when press the accelerator pedal release. 



APP1: 3.43-4.69 V  



APP2: 1.13-1.88V  



APP3: 0.64-1.28 V  



Are all PIDs signals out of range for the 
pedal fully depressing and released 
positions?  

Yes Go to the next step.

No

Go to Step 6.

5

INSPECT REFERENCE VOLTAGE TO APP 
SENSOR  



Turn the ignition switch off.  



Disconnect the APP sensor connector.  



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

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 10:08:42 AM

Page 381 

© 2005 Mitchell Repair Information Company, LLC. 



Measure the voltage between the APP 
sensor connector D or F terminal (wiring 
harness side) and the APP sensor connector 
C or G terminal (wiring harness side)  



Is the voltage between 4-6 V?  

No

Repair if necessary. Then go to Step 12.

6

INSPECT FUNCTIONALITY OF APP 
CIRCUITS 

 



Are APP1, APP2 or APP3 out of range?  

NOTE:



Use the voltage measurements from 
Step 4.  

Yes Go to the next Step.

No

Go to Step 11.

7

INSPECT FUNCTIONALITY OF APP 
SENSOR  



Turn the ignition switch off.  



Disconnect the APP sensor connector.  



Measure the resistance between the 
following APP sensor terminals (APP 
sensor component side). 



E and D or F: 600-1,370 ohms  



E and C or G: 720-1,660 ohms  



E and H: 1,300-2,960 ohms  



E and B: 1,250-2,860 ohms  



H and D or F: 750-1,720 ohms  



H and C or G: 660-1,520 ohms  



H and B: 1,230-2,810 ohms  



B and D or F: 710-1,640 ohms  



B and C or G: 580-1,340 ohms  



D or F and C or G: 200-470 ohms  



Are all the resistances within 
specifications?  

Yes Go to next Step.

No

Replace the accelerator pedal. Then go to 

Step 12.

8

INSPECT APP SENSOR SIGNAL CIRCUIT 
FOR OPEN CIRCUIT  



Disconnect the PCM connector.  



Inspect for continuity between the 
following terminals: 



P2121: APP sensor terminal E and 

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 10:08:42 AM

Page 382 

© 2005 Mitchell Repair Information Company, LLC. 

PCM terminal 1AK  



P2126: APP sensor terminal H and 
PCM terminal 1AG  



P2131: APP sensor terminal B and 
PCM terminal 1AC  



Are there continuity?  

No

Repair or replace suspected part, then go to 

Step 12.

9

INSPECT APP SENSOR SIGNAL CIRCUIT 
FOR SHORT TO GROUND  



Turn the ignition switch off.  



Inspect for continuity between the 
following terminals: 



P2121: APP sensor terminal E and 
body ground  



P2126: APP sensor terminal H and 
body ground  



P2131: APP sensor terminal B and 
body ground  



Are there continuity?  

Yes

Repair or replace suspected part, then go to 
Step 12.

No

Go to the next Step.

10

INSPECT APP 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: 



P2121: APP sensor terminal E and 
body ground  



P2126: APP sensor terminal H and 
body ground  



P2131: APP sensor terminal B and 
body ground  



Are the voltage B+?  

Yes

Repair or replace suspected part, then go to 
Step 12.

No

Go to the next Step.

INSPECT APP SENSOR SIGNAL CIRCUIT 
FOR SHORT EACH OTHER  



Turn the ignition switch off.  



Disconnect PCM connector.  



Disconnect APP sensor connector.  



Measure the resistance between the 
following APP sensor terminals (wiring 
harness-side) 

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 10:08:42 AM

Page 383 

© 2005 Mitchell Repair Information Company, LLC. 

11



P2121 

E and H 

E and B 

E and D or F 

E and C or G 



P2126 

H and E 

H and B 

H and D or F 

H and C or G 



P2131 

Band E 

B and H 

B and D or F 

B and C or G 



Are there resistance greater than 10 
kilohms?  

No

Repair or replace suspected part, then go to 

the next step.

12

VERIFY TROUBLESHOOTING OF DTC 
P2121, P2126 or P2131 HAS BEEN 
COMPLETED  



Verify that all disconnected connectors 
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].) 

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 10:08:42 AM

Page 384 

© 2005 Mitchell Repair Information Company, LLC.