Mazda CX 7. Manual - part 68

ON-BOARD DIAGNOSTIC [L3 WITH TC]

01-02–227

01-02

3

VERIFY RELATED PENDING CODE OR 
STORED DTCS

• Turn the ignition switch to off, then to the ON 

position (Engine off).

• Verify related pending code or stored DTCs.

• Are other DTCs present?

Yes

If misfire the DTC is present, go to Step 8.
If other DTCs is present, go to the applicable DTC 
inspection.
 (See01-02-13 DTC TABLE[L3 WITH TC].)

No

If driveability concern is present, go to Step 8.
If not, go to the next step.

4

IDENTIFY TRIGGER DTC FOR FREEZE FRAME 
DATA

• Is DTC P2178 on FREEZE FRAME DATA?

Yes

Go to the next step.

No

Go to troubleshooting procedures for DTC on FREEZE 
FRAME DATA.

5

VERIFY CURRENT INPUT SIGNAL STATUS 
(IGNITION SWITCH TO THE ON POSITION/
IDLE)

• Access the APP1, APP2, ECT, MAF, TP and 

VSS PIDs using the M-MDS.

• Is there any signal that is far out of specification 

when the ignition switch is at the ON position 
and engine runs?

Yes

Inspect the sensor and excessive resistance in related 
wiring harnesses.
Repair or if necessary.
Then go to Step 19.

No

Go to the next step.

6

VERIFY CURRENT INPUT SIGNAL STATUS 
UNDER TROUBLE CONDITION

• Inspect the same PIDs as Step 5 while 

simulating FREEZE FRAME DATA condition.

• Is there any signal which causes drastic 

changes?

Yes

Inspect the sensor and related wiring harnesses, repair or 
replace it.
Then go to Step 19.

No

Go to the next step.

7

VERIFY CURRENT INPUT SIGNAL STATUS OF 
FRONT HO2S

• Access the O2S11 for P2177 PID using the M-

MDS.

• Check the PID under following accelerator 

pedal condition in NEUTRAL.

• Is the PID reading normal?

— –0.1— 0.1 A when idle

— Below 0.25 mA just after release of 

accelerator pedal (lean condition)

Yes

Go to the next step.

No

Visually inspect for any gas leakage between the exhaust 
manifold and the front HO2S.
Then go to Step 19.

8

VERIFY CURRENT INPUT SIGNAL STATUS OF 
MAF SENSOR

• Connect the M-MDS to the DLC-2.

• Start the engine.

• Access the MAF PID.

• Verify that the MAF PID changes quickly 

according to engine speed.

• Is the PID normal?

Yes

Go to the next step.

No

Replace the MAF/IAT sensor, then go to Step 19.

9

INSPECT PURGE SOLENOID OPERATION

• Perform the Purge Control System Inspection.

 (See01-03-78 ENGINE CONTROL SYSTEM 
OPERATION INSPECTION[L3 WITH TC].)

• Does the purge control system work properly?

Yes

Go to the next step.

No

Repair or replace the malfunctioning part according to 
inspection result, then go to Step 19.

10

INSPECT PCV VALVE OPERATION

• Inspect the PCV valve operation.

 (See01-16-14 POSITIVE CRANKCASE 
VENTILATION (PCV) VALVE INSPECTION[L3 
WITH TC].)

• Is the PCV valve normal?

Yes

Go to the next step.

No

Replace the PCV valve, then go to Step 19.

11

INSPECT VARIABLE SWIRL CONTROL 
OPERATION

• Perform the Variable Swirl Control Operation 

Inspection.
 (See01-03-78 ENGINE CONTROL SYSTEM 
OPERATION INSPECTION[L3 WITH TC].)

• Does the variable swirl control work properly?

Yes

Go to the next step.

No

Repair or replace the malfunctioning part according to 
inspection result, then go to Step 19.

STEP

INSPECTION

ACTION

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ON-BOARD DIAGNOSTIC [L3 WITH TC]

01-02–228

End Of Sie

12

INSPECT VARIABLE VALVE TIMING CONTROL 
SYSTEM OPERATION

• Inspect the variable valve timing control system 

operation.
 (See01-03-78 ENGINE CONTROL SYSTEM 
OPERATION INSPECTION[L3 WITH TC].)

• Does the variable valve timing control system 

work properly?

Yes

Go to the next step.

No

Repair or replace the malfunctioning part according to 
inspection results, then go to Step 18.

13

INSPECT IF EGR VALVE IS STUCK OPEN

• Remove the EGR valve.

• Does the EGR valve stuck open?

Yes

Clean or replace the EGR valve, then go to Step 19.

No

Go to the next step.

14

INSPECT FUEL PRESSURE (HIGH-SIDE)

• Access and monitor FUEL_PRES PID.

• Is the FUEL_PRES PID value within the 

specified?
 (See01-40-6 PCM INSPECTION[L3 WITH 
TC].)

Yes

Go to Step 18.

No

Go to the next step.

15

IDENTIFY CAUSE BY FUEL PRESSURE 
SENSOR OR HIGH PRESSURE FUEL PUMP

• Is the vehicle accelerate performance 

normally?

Yes

Go to the next step.

No

Go to Step 17.

16

INSPECT FUEL PRESSURE SENSOR

• Inspect the fuel pressure sensor.

 (See01-40-35 FUEL PRESSURE SENSOR 
INSPECTION[L3 WITH TC].)

• Is the fuel pressure sensor normal?

Yes

Go to Step 19.

No

Replace the fuel delivery pipe, then go to Step 19.

17

INSPECT HIGH PRESSURE FUEL PUMP

• Replace the high pressure fuel pump

• Monitor FUEL_PRES PID

• Is the FUEL_PRES PID value within the 

specified?

 (See01-40-6 PCM INSPECTION[L3 WITH TC].)

Yes

Go to Step 19.

No

Go to the next step.

18

INSPECT FUEL PRESSURE (LOW-SIDE)

• Connect the fuel pressure gauge between fuel 

pump and high pressure fuel pump.

• Measure the low side fuel pressure.

 (See01-14-5 FUEL LINE PRESSURE 
INSPECTION[L3 WITH TC].)

• Is the low side fuel pressure within the 

specified?

Yes

Go to the next step.

No

Inspect for following:

• Fuel line restriction

• Fuel filter clogging

If okay replace the fuel pump. Then go to the next step.

19

VERIFY TROUBLESHOOTING OF DTC P2188 
COMPLETED

• Make sure to reconnect all disconnected 

connectors.

• Clear the DTC from the PCM memory using 

the M-MDS.

• Perform the PCM Adaptive Memory Produce 

Drive Mode. (See01-02-10 OBD-II DRIVE 
MODE[L3 WITH TC].)

• Is the PENDING CODE for this DTC present?

Yes

Replace the PCM, then go to the next step.
 (See01-40-6 PCM REMOVAL/INSTALLATION[L3 WITH 
TC].)

No

Go to the next step.

20

VERIFY AFTER REPAIR PROCEDURE

• Perform the “AFTER REPAIR PROCEDURE”.

 (See01-14-4 AFTER REPAIR 
PROCEDURE[L3 WITH TC].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.
 (See01-02-13 DTC TABLE[L3 WITH TC].)

No

Troubleshooting completed.

STEP

INSPECTION

ACTION

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ON-BOARD DIAGNOSTIC [L3 WITH TC]

01-02–229

01-02

DTC P2195[L3 WITH TC]

id010239812700

Diagnostic procedure

DTC P2195

Front HO2S signal stuck lean

DETECTION 

CONDITION

• The PCM monitors the front HO2S output current when the following conditions are met. If the average 

output current is more than 1.2 A for25 s, the PCM determines that the front HO2S has a malfunction.

MONITORING CONDITION

— ECT: more than 70 — 150 

°C {158— 302 °F}

— Engine speed: 1,000— 3,200 rpm

— Charging efficiency: 20— 62.5%

— Output voltage from the rear HO2S: 0.2 V or above

Diagnostic support note

• This is an intermittent monitor (HO2S).

• MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in 

one drive cycle while the DTC for the same malfunction has been stored in the PCM.

• PENDING CODE is available if the PCM detects the above malfunction condition during the first drive 

cycle.

• FREEZE FRAME DATA is available.

• The DTCs are stored in the PCM memory.

POSSIBLE 

CAUSE

• Front HO2S malfunction

• Fuel injector malfunction

• Insufficient fuel line pressure

• Fuel pressure sensor malfunction

• Relief valve (built-in fuel delivery pipe) malfunction

• Spill valve control solenoid valve (built-in high pressure fuel pump) malfunction

• High pressure fuel pump malfunction

• Exhaust gas leakage

• Air suction at intake-air system malfunction

• Fuel leakage

• MAF sensor malfunction

• ECT sensor malfunction

• PCM malfunction

STEP

INSPECTION

ACTION

1

VERIFY FREEZE FRAME DATA AND 
DIAGNOSTIC MONITORING TEST RESULTS 
HAVE BEEN RECORDED

• Have the FREEZE FRAME DATA and 

DIAGNOSTIC MONITORING TEST RESULTS 
(HO2S related) been recorded?

Yes

Go to the next step.

No

Record the FREEZE FRAME DATA and DIAGNOSTIC 
MONITORING TEST RESULTS 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 repair information available?

Yes

Perform the repair or diagnosis according to the available 
repair information.

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

No

Go to the next step.

3

VERIFY RELATED PENDING CODE OR 
STORED DTC

• Turn the ignition switch to off, then to ON 

position (Engine off).

• Verify the related PENDING CODE or stored 

DTCs.

• Is the DTC P2177 or P2187 also present?

Yes

Go to the applicable DTC inspection.
 (See01-02-13 DTC TABLE[L3 WITH TC].)

No

Go to the next step.

4

IDENTIFY TRIGGER DTC FOR FREEZE FRAME 
DATA

• Is DTC P2195 on FREEZE FRAME DATA?

Yes

Go to the next step.

No

Go to FREEZE FRAME DATA DTC inspection.
 (See01-02-13 DTC TABLE[L3 WITH TC].)

5

VERIFY CURRENT INPUT SIGNAL STATUS

• Connect the M-MDS to the DLC-2.

• Verify the following PIDs.

 (See01-40-6 PCM INSPECTION[L3 WITH 
TC].)
— APP1

— APP2

— ECT

— MAF

— TP

— VSS

• Are the PIDs normal?

Yes

Go to the next step.

No

Inspect the malfunctioning part according to the inspection 
results.
Then go to Step 16.

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ON-BOARD DIAGNOSTIC [L3 WITH TC]

01-02–230

6

VERIFY CURRENT INPUT SIGNAL STATUS 
UNDER FREEZE FRAME DATA CONDITION

• Connect the M-MDS to the DLC-2.

• Verify the following PIDs under FREEZE 

FRAME DATA condition.
 (See01-40-6 PCM INSPECTION[L3 WITH 
TC].)
— APP1

— APP2

— ECT

— MAF

— TP

— VSS

• Are the PIDs normal?

Yes

Go to the next step.

No

Inspect the malfunctioning part according to the inspection 
results.
Then go to Step 16.

7

INSPECT INTAKE-AIR SYSTEM FOR 
EXCESSIVE AIR SUCTION

• Visually inspect for loosen, cracks or damages 

hose in intake-air system.

• Is there any malfunction?

Yes

Repair or replace the malfunctioning part, then go to Step 
16.

No

Go to the next step.

8

VERIFY CURRENT INPUT SIGNAL STATUS OF 
MAF SENSOR

• Connect the M-MDS to the DLC-2.

• Start the engine.

• Access the MAF PID.

• Verify that the MAF PID changes quickly 

according to engine speed.

• Is the PID normal?

Yes

Go to the next step.

No

Replace the MAF/IAT sensor, then go to Step 16.

9

INSPECT FRONT HO2S

• Inspect the front HO2S.

 (See01-40-37 HEATED OXYGEN SENSOR 
(HO2S) INSPECTION[L3 WITH TC].)

• Is there any malfunction?

Yes

Replace the front HO2S, then go to Step 16.
 (See01-15-2 EXHAUST SYSTEM REMOVAL/
INSTALLATION[L3 WITH TC].)

No

Go to the next step.

10

INSPECT FUEL INJECTOR

• Inspect the fuel injector.

 (See01-14-27 FUEL INJECTOR 
INSPECTION[L3 WITH TC].)

• Is there any malfunction?

Yes

Replace the suspected fuel injector, then go to Step 16.
 (See01-14-23 FUEL INJECTOR REMOVAL/
INSTALLATION[L3 WITH TC].)

No

Go to the next step.

11

INSPECT FUEL PRESSURE (HIGH-SIDE)

• Access and monitor FUEL_PRES PID.

• Is the FUEL_PRES PID value within the 

specified?
 (See01-40-6 PCM INSPECTION[L3 WITH 
TC].)

Yes

Go to Step 15.

No

Go to the next step.

12

IDENTIFY CAUSE BY FUEL PRESSURE 
SENSOR OR HIGH PRESSURE FUEL PUMP

• Is the vehicle accelerate performance 

normally?

Yes

Go to the next step.

No

Go to Step 14.

13

INSPECT FUEL PRESSURE SENSOR

• Inspect the fuel pressure sensor.

 (See01-40-35 FUEL PRESSURE SENSOR 
INSPECTION[L3 WITH TC].)

• Is the fuel pressure sensor normal?

Yes

Go to Step 15.

No

Replace the fuel delivery pipe, then go to Step 16.

14

INSPECT HIGH PRESSURE FUEL PUMP

• Replace the high pressure fuel pump

• Monitor FUEL_PRES PID

• Is the FUEL_PRES PID value within the 

specified?

 (See01-40-6 PCM INSPECTION[L3 WITH TC].)

Yes

Go to Step 16.

No

Go to the next step.

STEP

INSPECTION

ACTION

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