Mazda CX-9 Grand Touring. Manual - part 280

CONDITION 

voltage or ground.  

POSSIBLE CAUSE 



Connector or terminal malfunction  



Open circuit between cruise control switch terminal B and PCM terminal 
1AT  



Open circuit between cruise control switch terminal C and PCM terminal 1AP



Short to power supply between cruise control switch terminal B and PCM 
terminal 1AT  



Short to power supply between cruise control switch terminal C and PCM 
terminal 1 AP  



Short to ground circuit between cruise control switch terminal B and PCM 
terminal 1AT  



Short to ground circuit between cruise control switch terminal C and PCM 
terminal 1AP  



Cruise control switch malfunction  



PCM malfunction  

 

2008 Mazda CX-9 Grand Touring 

2008 ENGINE PERFORMANCE On-Board Diagnostic (MZI-3.7) - Mazda CX-9

  

Microsoft 

 

Sunday, November 15, 2009 10:08:39 AM

Page 253 

© 2005 Mitchell Repair Information Company, LLC. 

DIAGNOSTIC PROCEDURE 

DTC P0579 (MZI-3.7) DIAGNOSTIC PROCEDURE 

STEP

INSPECTION

ACTION

1

VERIFY FREEZE FRAME DATA HAS 
BEEN RECORDED  



Has 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.

2

VERIFY RELATED REPAIR 
INFORMATION AVAILABILITY  



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



Is any related Service Bulletins 

Yes

Perform repair or diagnosis according to the 
available Service Bulletins. 



If the vehicle is not repaired, 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 10:08:39 AM

Page 254 

© 2005 Mitchell Repair Information Company, LLC. 

available?  

No

Go to the next step.

3

INSPECT CRUISE CONTROL SWITCH 
CONNECTOR FOR POOR 
CONNECTION  



Turn the ignition switch to off.  



Disconnect the cruise control switch 
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

IINSPECT CRUISE CONTROL SWITCH 
CIRCUIT FOR SHORT TO POWER 
SUPPLY 



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



Measure the voltage between the 
following terminals: 



Cruise control switch terminal B 
and body ground  



Cruise control switch terminal C 
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 CRUISE CONTROL SWITCH 
CIRCUIT FOR SHORT TO GROUND  



Turn the ignition switch off.  



Inspect for continuity between the 
following terminals: 



Cruise control switch terminal B 
and body ground  



Cruise control switch terminal C 
and body ground  



Are there continuity?  

Yes

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

No

Go to the next step.

6

INSPECT PCM CONNECTOR FOR 
POOR CONNECTION  



Turn the ignition switch off.  



Disconnect the PCM 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.

 

2008 Mazda CX-9 Grand Touring 

2008 ENGINE PERFORMANCE On-Board Diagnostic (MZI-3.7) - Mazda CX-9

  

Microsoft 

 

Sunday, November 15, 2009 10:08:39 AM

Page 255 

© 2005 Mitchell Repair Information Company, LLC. 

DTC P0581 [MZI-3.7] 

DTC P0581 (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES 

7

INSPECT CRUISE CONTROL SWITCH 
CIRCUIT FOR OPEN  



Disconnect the PCM connector.  



Inspect for continuity between the 
following terminals: 



Cruise control switch terminal B 
and PCM terminal 1AT  



Cruise control switch terminal C 
and PCM terminal 1AP  



Are there continuity?  

Yes Go to the next step.

No

Repair or replace suspected part, then go to Step 

9.

8

INSPECT CRUISE CONTROL SWITCH
 



Inspect the cruise control switch. (See 
CRUISE CONTROL SWITCH 
INSPECTION [MZI-3.7] .)  



Is there malfunction?  

Yes

Replace the cruise control switch, then go to the 
next step.

No

Go to the next step.

9

VERIFY TROUBLESHOOTING OF 
DTC P0579 HAS BEEN COMPLETED  



Verify that all disconnected 
connectors are reconnected.  



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



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



Perform the "KOEO and KOER self-
test". (See KOEO/KOER SELF 
TEST [MZI-3.7].)  



Retrieve DTCs using the M-MDS.  



Is the PENDING CODE for this 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.

10

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.

 

2008 Mazda CX-9 Grand Touring 

2008 ENGINE PERFORMANCE On-Board Diagnostic (MZI-3.7) - Mazda CX-9

  

Microsoft 

 

Sunday, November 15, 2009 10:08:39 AM

Page 256 

© 2005 Mitchell Repair Information Company, LLC.