Mazda CX-9 Grand Touring. Manual — part 239

2008 Mazda CX-9 Grand Touring

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

Microsoft

Sunday, November 15, 2009 10:08:35 AM

Page 89

© 2005 Mitchell Repair Information Company, LLC.

DIAGNOSTIC PROCEDURE

DTC P0133, P0139, P0153, P0159 (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
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

PERFORM KOER SELF-TEST



Verify that the engine is at normal
operating temperature.



Perform the KOER self-test.



Are DTCs P0040, P0041 or P1127
present?

Yes

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

No

Go to the next step.

4

INSPECT FOR UNMETERED AIR
LEAKS



Carefully inspect the following areas
for potential air leaks:



Hoses connecting to the MAF
sensor assembly



Hoses connecting to the throttle
body



Intake manifold gasket leaks



PCV system



The vacuum lines are
disconnected



Improperly seated engine oil
dipstick, tube or oil filler cap

NOTE:



Fuel calculations can be affected by
unmetered air leaks.

Yes

Repair the source of the air leak. Then go to
Step 17.

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 10:08:35 AM

Page 90

© 2005 Mitchell Repair Information Company, LLC.



Exhaust leaks at flanges and
gaskets



Are any air leaks present?

5

INSPECT HO2S CIRCUIT (S) FOR
OPEN CIRCUIT IN WIRING HARNESS



Turn the ignition switch off.



Remove the jumper wire (s).



Visually inspect the HO2S wiring
harness for exposed wiring, water
contamination, corrosion, and proper
assembly.



Disconnect the PCM connector.



Measure the resistance between the
following terminals:



PCM terminal 2Y (wiring
harness-side) and front HO2S
(RH) terminal B (wiring harness-
side)



PCM terminal 2BG (wiring
harness-side) and rear HO2S
(RH) terminal B (wiring harness-
side)



PCM terminal 2U (wiring
harness-side) and front HO2S
(LH) terminal B (wiring harness-
side)



PCM terminal 2BC (wiring
harness-side) and rear HO2S
(LH) terminal B (wiring harness-
side)



PCM terminal 2AL (wiring
harness-side) and HO2S terminal
D (wiring harness-side)



Are the resistances less than 5 ohms?

Yes Go to the next step.

No

Repair or replace suspected part, Then go to

Step 17.

INSPECT HO2S CIRCUIT FOR SHORT
TO POWER SUPPLY



Measure the resistance between the
following terminals:



PCM terminal 1BJ (wiring
harness-side) and PCM terminal
2Y (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 10:08:35 AM

Page 91

© 2005 Mitchell Repair Information Company, LLC.

6



PCM terminal 1 BJ (wiring
harness-side) and PCM terminal
2BG (wiring harness-side)



PCM terminal 1 BJ (wiring
harness-side) and PCM terminal
2U (wiring harness-side)



PCM terminal 1BJ (wiring
harness-side) and PCM terminal
2BC (wiring harness-side)



Is the resistance more than 10 kilohms?

No

Go to Step 10.

7

INSPECT FOR SOURCE OF
POTENTIAL HO2S CONTAMINATION



Investigate the following items as
potential sources of HO2S
contamination:



Use of unapproved silicon sealers



Fuel contaminated by silicon
additives



Excessive oil consumption



Glycol leaking internally in the
engine



Lead-contaminated fuel



Short drive cycles in cold weather



Use of unapproved cleaning
agents



Is a concern present?

Yes

Repair the source of the contamination. Change
the engine oil and oil filter. Then go to Step 17.

No

Go to the next step.

8

VISUALLY INSPECT HO2S WIRING
HARNESS



Connect the PCM connector.



Visually inspect the HO2S wiring
harness for exposed wiring water
contamination, corrosion, and proper
assembly.



Is a concern present?

Yes Repair if necessary. Then go to the next step.

No

Go to the next step.

INSPECT HO2S AND SIGRTN
CIRCUITS FOR OPEN CIRCUIT IN
WIRING HARNESS

NOTE:



Verify the wiring harness terminals

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 10:08:35 AM

Page 92

© 2005 Mitchell Repair Information Company, LLC.