Mazda CX-9 Grand Touring. Manual - part 252

DIAGNOSTIC PROCEDURE 

DTC P0230 (MZI-3.7) DIAGNOSTIC PROCEDURE 



PCM malfunction  

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 availability.  



Is any related Service Bulletins available?  

Yes

Perform repair or diagnosis according 
to available Service Bulletins. 



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

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 10:08:36 AM

Page 141 

© 2005 Mitchell Repair Information Company, LLC. 

3

VERIFY RELATED PENDING CODE OR 
STORED DTC  



Verify the related PENDING CODE or stored 
DTCs.  



Are other DTCs present?  

Yes

Go to appropriate DTC inspection. 
(See DTC TABLE [MZI-3.7].)

No

Go to the next step.

4

INSPECT FUEL PUMP RELAY CONNECTOR 
FOR POOR CONNECTION  



Turn the ignition switch off.  



Disconnect the fuel pump relay.  



Inspect for poor connection (such as 
damaged/pulled-out pins, corrosion).  



Are there malfunction?  

Yes

Repair or replace suspected part, then 
go to Step 10.

No

Go to the next step.

5

INSPECT PCM CONNECTOR FOR POOR 
CONNECTION  



Turn the ignition switch off.  



Disconnect PCM connector.  



Inspect for poor connection (such as 
damaged/pulled-out pins, corrosion).  



Are there malfunction?  

Yes

Repair or replace suspected part, then 
go to Step 10.

No

Go to the next step.

6

INSPECT FUEL PUMP RELAY POWER 
SUPPLY CIRCUIT FOR OPEN CIRCUIT  



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



Measure voltage between fuel pump relay 
connector terminal A (harness-side) and body 
ground.  



Is voltage B+?  

Yes Go to the next step.

No

Repair or replace suspected part, then 

go to Step 10.

7

INSPECT FUEL PUMP CONTROL CIRCUIT 
FOR SHORT TO GROUND  



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



Inspect for continuity between fuel pump relay 
connector terminal E (harness-side) and body 
ground.  



Is there continuity?  

Yes

Repair or replace suspected part, then 
go to Step 10.

No

Go to the next step.

INSPECT FUEL PUMP CONTROL CIRCUIT 
FOR OPEN CIRCUIT  

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 10:08:36 AM

Page 142 

© 2005 Mitchell Repair Information Company, LLC. 

DTC P0231 [MZI-3.7] 

DTC P0231 (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES 

8



Turn the ignition switch off.  



Inspect for continuity between fuel pump relay 
terminal E and PCM terminal 1V.  



Is there continuity?  

No

Repair or replace suspected part, then 

go to Step 10.

9

INSPECT FUEL PUMP RELAY  



Inspect the fuel pump relay. (See RELAY 
INSPECTION .)  



Is there any malfunction?  

Yes

Replace the fuel pump relay, then go 
to the next step.

No

Go to the next step.

10

VERIFY TROUBLESHOOTING OF DTC P0230 
HAS BEEN COMPLETED  



Verify that all disconnected connectors 
reconnected.  



Clear DTC from memory using M-MDS.  



Start the engine.  



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



Is same DTC present?  

Yes

Replace the PCM, then go to the next 
step.

No

Go to the next step.

11

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.

DTC P0231

FP secondary circuit low

DETECTION 

CONDITION 



The PCM monitors the fuel pump monitor circuit. The test fails if the PCM 
commands the fuel pump ON and B+ voltage is not detected on the FPM circuit.  

POSSIBLE CAUSE 



Fuel pump relay malfunction  



Connector or terminal malfunction  



Open circuit between battery and fuel pump relay terminal C  



Open circuit between fuel pump relay terminal D and PCM terminal 1Q  

 

2008 Mazda CX-9 Grand Touring 

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

  

Microsoft 

 

Sunday, November 15, 2009 10:08:36 AM

Page 143 

© 2005 Mitchell Repair Information Company, LLC. 

DIAGNOSTIC PROCEDURE 

DTC P0231 (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 availability.  



Is any related Service Bulletins available?  

Yes

Perform repair or diagnosis 
according to available Service 
Bulletins. 



If 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 10:08:36 AM

Page 144 

© 2005 Mitchell Repair Information Company, LLC.