Mazda CX-9 Grand Touring. Manual - part 287

DIAGNOSTIC PROCEDURE 

DTC P0620 (MZI-3.7) DIAGNOSTIC PROCEDURE 

STEP

INSPECTION

ACTION

1

VERIFY FREEZE FRAME DATA HAS 
BEEN RECORDED  



Has FREEZE FRAME DATA been 

Yes Go to the next step.

No

Record FREEZE FRAME DATA on the repair 

 

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 281 

© 2005 Mitchell Repair Information Company, LLC. 

recorded?  

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 
available?  

Yes

Perform repair or diagnosis according to the 
available Service Bulletins. 



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

No

Go to the next step.

3

INSPECT DRIVE BELT CONDITION  



Verify that drive belt auto tensioner 
indicator mark does not exceed limit.  



Is drive belt normal?  

Yes Go to the next step.

No

Replace and/or adjust drive belt, then go to Step 

12. (See DRIVE BELT INSPECTION [MZI-

3.7] .)

4

INSPECT GENERATOR TERMINAL 
FOR POOR INSTALLATION  



Turn the engine switch off.  



Inspect generator terminal B for 
looseness.  



Are there any malfunction?  

Yes

Connect generator terminal B correctly, then go 
to Step 12.

No

Go to the next step.

5

INSPECT GENERATOR CIRCUIT FOR 
SHORT TO POWER SUPPLY  



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



Measure voltage between generator 
terminal LI (wiring harness-side) and 
body ground.  



Is voltage B+?  

Yes

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

No

Go to the next step.

6

INSPECT GENERATOR CIRCUIT FOR 
SHORT TO GROUND  



Inspect for continuity between 
generator terminal LI (wiring harness-
side) and body ground.  



Is there continuity?  

Yes

Repair or replace suspected part, then go to the 
next step.

No

Go to the next step.

7

INSPECT PCM CONNECTOR FOR 
POOR CONNECTION  



Turn the engine switch off.  



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



Are there any malfunction?  

Yes

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

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 282 

© 2005 Mitchell Repair Information Company, LLC. 

8

INSPECT GENERATOR CIRCUIT FOR 
OPEN CIRCUIT  



Inspect for continuity between 
generator terminal LI (wiring harness-
side) and PCM terminal 2AG (wiring 
harness-side)  



Is there continuity?  

Yes Go to the next step.

No

Repair or replace suspected part, then go to Step 

12.

9

INSPECT BATTERY POSITIVE 
TERMINAL FOR POOR 
INSTALLATION  



Turn the engine switch off.  



Inspect the battery positive terminal 
for looseness.  



Is there any malfunction?  

Yes

Connect the battery positive terminal correctly, 
then go to Step 12.

No

Go to the next step.

10

INSPECT GENERATOR CIRCUIT FOR 
OPEN CIRCUIT  



Inspect continuity between generator 
terminal B (wiring harness-side) and 
battery positive terminal (wiring 
harness-side).  



Is there continuity?  

Yes Go to the next step.

No

Repair or replace suspected part, then go to Step 

12.

11

INSPECT GENERATOR  



Inspect the generator. (See 
GENERATOR INSPECTION 
[MZI-3.7] .)  



Is there any malfunction?  

Yes

Replace the generator, then go to the next step. 
(See GENERATOR 
REMOVAL/INSTALLATION [MZI-3.7] .)

No

Go to the next step.

12

VERIFY TROUBLESHOOTING OF 
DTC P0620 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].)  



Is the PENDING CODE for the 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.

VERIFY AFTER REPAIR PROCEDURE

 

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 283 

© 2005 Mitchell Repair Information Company, LLC. 

DTC P0625 [MZI-3.7] 

DTC P0625 (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES 

13

 



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 P0625

Generator field terminal circuit low

DETECTION 

CONDITION 



The PCM monitors generator load from the generator/regulator in the form of 
frequency. The concern indicates the input is lower than the load should be in normal 
operation. The load input could be low when no generator output exists.  

POSSIBLE 

CAUSE 



Drive belt damaged  



Generator malfunction  



Short to ground between generator terminal RC and PCM terminal 2S  



Short to ground between generator terminal LI and PCM terminal 2AG  



Open circuit between terminal B and battery positive terminal  



Low system voltage  



Connector or terminal 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 284 

© 2005 Mitchell Repair Information Company, LLC.