Mazda CX-9 Grand Touring. Manual - part 247

3

INSPECT FUEL INJECTOR NO.2 CONNECTOR 
FOR POOR CONNECTION  



Turn the ignition switch off.  



Disconnect the fuel injector No.2 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 8.

No

Go to the next step.

4

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).  



Is there malfunction?  

Yes

Repair or replace suspected part, 
then go to Step 8.

No

Go to the next step.

5

INSPECT FUEL INJECTOR NO.2 POWER SUPPLY 
CIRCUIT FOR OPEN CIRCUIT  



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



Measure the voltage between fuel injector No.2 
connector terminal B and body ground.  



Is the voltage B+?  

Yes Go to the next step.

No

Repair or replace suspected part, 

then go to Step 8.

6

INSPECT FUEL INJECTOR NO.2 SIGNAL 
CIRCUIT FOR OPEN CIRCUIT  



Inspect continuity between fuel injector No.2 
terminal A (wiring harness-side) and PCM terminal 
2BM (wiring harness-side).  



Is there continuity?  

Yes Go to the next step.

No

Repair or replace suspected part, 

then go to Step 8.

7

INSPECT FUEL INJECTOR NO.2  



Inspect the fuel injector No.2. (See FUEL 
INJECTOR INSPECTION [MZI-3.7] .)  



Is there any malfunction?  

Yes

Replace the fuel injector No.2, then 
go to the next step.

No

Go to the next step.

8

VERIFY TROUBLESHOOTING OF DTC P0202 
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 

Yes

Replace the PCM, then 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 121 

© 2005 Mitchell Repair Information Company, LLC. 

DTC P0203 [MZI-3.7] 

DTC P0203 (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES 

KOEO/KOER SELF TEST [MZI-3.7].)  



Is same DTC present?  

No

Go to the next step.

9

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 P0203

Injector circuit/open-cylinder No.3

DETECTION 

CONDITION 



The CCM monitors the operation of the fuel injector drivers in the PCM. The test
fails if the fuel injector circuitry is inoperative.  

POSSIBLE CAUSE 



Fuel injector No.3 malfunction  



Connector or terminal malfunction  



Open circuit between fuel pump relay and fuel injector No.3 terminal B  



Open circuit between fuel injector No.3 terminal A and PCM terminal 2BF  

 

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 122 

© 2005 Mitchell Repair Information Company, LLC. 

DIAGNOSTIC PROCEDURE 

DTC P0203 (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.  

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 123 

© 2005 Mitchell Repair Information Company, LLC. 

3

INSPECT FUEL INJECTOR NO.3 CONNECTOR 
FOR POOR CONNECTION  



Turn the ignition switch off.  



Disconnect the fuel injector No.3 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 8.

No

Go to the next step.

4

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).  



Is there malfunction?  

Yes

Repair or replace suspected part, 
then go to Step 8.

No

Go to the next step.

5

INSPECT FUEL INJECTOR NO.3 POWER SUPPLY 
CIRCUIT FOR OPEN CIRCUIT  



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



Measure the voltage between fuel injector No.3 
connector terminal B and body ground.  



Is the voltage B+?  

Yes Go to the next step.

No

Repair or replace suspected part, 

then go to Step 8.

6

INSPECT FUEL INJECTOR NO.3 SIGNAL 
CIRCUIT FOR OPEN CIRCUIT  



Inspect continuity between fuel injector No.3 
terminal A (wiring harness-side) and PCM terminal 
2BF (wiring harness-side).  



Is there continuity?  

Yes Go to the next step.

No

Repair or replace suspected part, 

then go to Step 8.

7

INSPECT FUEL INJECTOR NO.3  



Inspect the fuel injector No.3. (See FUEL 
INJECTOR INSPECTION [MZI-3.7] .)  



Is there any malfunction?  

Yes

Replace the fuel injector No.3, then 
go to the next step.

No

Go to the next step.

8

VERIFY TROUBLESHOOTING OF DTC P0203 
HAS BEEN COMPLETED  



Verify that all disconnected connectors 
reconnected.  



Clear DTC from memory using M-MDS.  



Start the engine.  

Yes

Replace the PCM, then 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 124 

© 2005 Mitchell Repair Information Company, LLC.