Mazda CX 7. Manual - part 46

 

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Mazda CX 7. Manual - part 46

 

 

ON-BOARD DIAGNOSTIC [L3 WITH TC]

01-02–139

01-02

DTC P0442[L3 WITH TC]

id010239807500

Diagnostic procedure

DTC P0442

Evaporative emission control system leak detected (small leak)

DETECTION 

CONDITION

• PCM measures the pump load current (EVAP line pressure) when the specified period has passed after the 

EVAP system is sealed when the monitoring conditions are met. If the load does not reach the reference 
current value within the specified period, the PCM determines that the EVAP system has a small leak.

MONITORING CONDITION

— The ignition switch is turned off.

— IAT: 5— 35 

°C {40— 95 °F}

— Battery voltage: 11— 20 V

— Atmospheric pressure: 72.2 kPa {542 mmHg, 21.3 inHg} or above

— Fuel tank level: 15— 85%

Diagnostic support note

• This is an intermittent monitor (Evaporative emission system).

• 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.

• DTCs are stored in the PCM memory.

• DIAGNOSTIC MONITORING TEST RESULT is available.

POSSIBLE 

CAUSE

• Purge solenoid valve malfunction

• EVAP system leak detection pump malfunction

• Charcoal canister malfunction

• Fuel filler cap malfunction

• Fuel tank malfunction

• Fuel pump unit poor seal

• EVAP hose damaged or loose

• EVAP pipe damaged

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 
(Evaporative emission system related) been 
recorded?

Yes

Go to the next step.

No

Record FREEZE FRAME DATA and DIAGNOSTIC 
MONITORING TEST RESULTS on the repair order, then 
go to the next step.

2

VERIFY RELATED REPAIR INFORMATION 
AVAILABILITY

• Check for 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 DTCS

• Turn the ignition switch off then to the ON 

position (Engine off).

• Verify related PENDING CODE or stored 

DTCs.

• Are other DTCs present?

Yes

Go to the appropriate DTC inspection.

No

Go to the next step.

4

CLASSIFY INTERMITTENT CONCERN OR 
CONTINUOUS CONCERN

• Perform evaporative system leak inspection.

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

• Does the test result fail?

Yes

Go to the next step.

No

Intermittent concern exists. Inspect the purge solenoid 
valve and the EVAP system leak detection pump circuit for 
an intermittent concern.
 (See01-03-76 INTERMITTENT CONCERN 
TROUBLESHOOTING[L3 WITH TC].)

5

LOCATE LEAK POINT

• Inspect for leakage for the following using the 

Evaporative Emissions Tester.
— Charcoal canister

— Catch tank

— Fuel filler cap

— EVAP hoses and pipes

— Fuel tank

• Is leakage found?

Yes

Repair the leakage or replace the part, then go to Step 10.

No

Go to the next step.

1871-1U-06B(01-02).fm  139 ページ  2006年3月15日 水曜日 午前10時32分

ON-BOARD DIAGNOSTIC [L3 WITH TC]

01-02–140

End Of Sie

DTC P0443[L3 WITH TC]

id010239807600

6

INSPECT PURGE SOLENOID VALVE

• Inspect purge solenoid valve is stuck closed.

 (See01-16-9 PURGE SOLENOID VALVE 
INSPECTION[L3 WITH TC].)

• Is the purge solenoid valve normal?

Yes

Go to the next step.

No

Replace the purge solenoid valve, then go to Step 10.

7

INSPECT EVAP SYSTEM LEAK DETECTION 
PUMP

• Connect all disconnected connectors and 

hoses.

• Place the clamp on the EVAP system leak 

detection pump hose between the EVAP 
system leak detection pump and the air filter.

• Perform the evaporative system leak 

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

• Does the test result fail?

Yes

Go to Step 9.

No

Go to the next step.

8

CONFIRM EVAP SYSTEM LEAK DETECTION 
PUMP LEAKAGE

• Remove the clamp.

• Perform the evaporative system leak 

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

• Does the test result failed?

Yes

Replace the EVAP system leak detection pump, then go to 
Step 10.

No

Go to the next step.

9

INSPECT FUEL PUMP UNIT INSTALLATION

• Remove the fuel tank.

• Visually inspect for damage, insufficient sealing 

or a poorly installed pump unit.

• Is it normal?

Yes

Go to the next step.

No

Repair or replace the fuel tank or sealing, then go to the 
next step.

10

PERFORM LEAK INSPECTION

• Connect all disconnected connectors and 

hoses.

• Perform the evaporative system leak 

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

• Does the test result failed?

Yes

Leakage still exists. Locate the leak point and repair.
Then go to the next step.

No

Go to the next step

11

VERIFY AFTER REPAIR PROCEDURE

• Perform the “AFTER REPAIR PROCEDURE”.

 (See01-02-10 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

DTC P0443

EVAP control system purge control valve circuit malfunction

DETECTION 

CONDITION

• PCM monitors the input voltages from the purge solenoid valve. If the voltage remains low or high, the PCM 

determines that the purge solenoid valve circuit has a malfunction.

Diagnostic support note

• This is an continuous monitor (CCM).

• 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.

• DTCs are stored in the PCM memory.

POSSIBLE 

CAUSE

• Purge solenoid valve malfunction

• Connector or terminal malfunction

• Short to ground in the wiring harness between purge solenoid valve terminal B and PCM terminal 2AB

• Open circuit in the wiring harness between the main relay and purge solenoid valve terminal A

• Open circuit in the wiring harness between purge solenoid valve terminal B and PCM terminal 2AB

• Short to the power supply between purge solenoid valve terminal B and PCM terminal 2AB

• PCM malfunction

1871-1U-06B(01-02).fm  140 ページ  2006年3月15日 水曜日 午前10時32分

ON-BOARD DIAGNOSTIC [L3 WITH TC]

01-02–141

01-02

Diagnostic procedure

STEP

INSPECTION

ACTION

1

VERIFY FREEZE FRAME DATA HAS BEEN 
RECORDED

• Has the 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

• Check for 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

CLASSIFY OPEN CIRCUIT OR SHORT TO 
GROUND MALFUNCTION

• Disconnect the purge solenoid valve tube that 

is connected to the intake manifold.

• Connect the vacuum pump to the purge 

solenoid valve.

• Pump the vacuum pump several times and 

stop.

• Wait a few seconds.

• Is the vacuum maintained?

Yes

Go to Step 5.

No

Go to the next step.

4

INSPECT PASSAGE CONTROL OF PURGE 
SOLENOID VALVE

• Turn the ignition switch off.

• Disconnect the purge solenoid valve connector.

• Pump the vacuum pump several times and wait 

a few seconds.

• Is the vacuum maintained?

Yes

Repair or replace the wiring harness for a short to ground, 
then go to Step 10.

No

Replace the purge solenoid valve, then go to Step 10.

5

INSPECT PURGE SOLENOID VALVE 
CONNECTOR FOR POOR CONNECTION

• Turn the ignition switch off.

• Inspect for poor connection (damaged/pulled-

out pins, corrosion, etc.).

• Is there any malfunction?

Yes

Repair or replace the terminal, then go to Step 10.

No

Go to the next step.

6

INSPECT PURGE SOLENOID VALVE

• Perform the purge solenoid valve inspection.

 (See01-16-9 PURGE SOLENOID VALVE 
INSPECTION[L3 WITH TC].)

• Is the purge solenoid valve normal?

Yes

Go to the next step.

No

Replace the purge solenoid valve, then go to Step 10.

DTC P0443

EVAP control system purge control valve circuit malfunction

A

B

B

A

2AB 

PCM

PURGE SOLENOID VALVE

WIRING HARNESS SIDE CONNECTOR

PURGE SOLENOID VALVE

MAIN RELAY

7

5

8

5

9

6

PCM

WIRING HARNESS SIDE CONNECTOR

2BE 2BA 2AW 2AS 2AO 2AK 2AG 2AC 2Y 2U 2Q 2M

2E

2A

2I

2BH 2BD 2AZ 2AV 2AR 2AN 2AJ 2AF 2AB 2X 2T 2P

2H

2D

2L

2BG 2BC 2AY 2AU 2AQ 2AM 2AI 2AE 2AA 2W 2S 2O

2G

2C

2K

2BF 2BB 2AX 2AT 2AP 2AL 2AH 2AD 2Z

2V 2R 2N

2F

2B

2J

1871-1U-06B(01-02).fm  141 ページ  2006年3月15日 水曜日 午前10時32分

ON-BOARD DIAGNOSTIC [L3 WITH TC]

01-02–142

End Of Sie

DTC P0446[L3 WITH TC]

id010239807700

7

INSPECT PURGE SOLENOID VALVE POWER 
SUPPLY CIRCUIT FOR OPEN CIRCUIT

• Turn ignition switch to the ON position (Engine 

off).

• Measure the voltage between purge solenoid 

valve connector terminal A and body ground.

• Is the voltage B+?

Yes

Go to the next step.

No

Repair or replace the wiring harness for an open circuit, 
then go to Step 10.

8

INSPECT PCM CONNECTOR FOR POOR 
CONNECTION

• Turn the ignition switch off.

• Disconnect the PCM connector.

• Inspect for poor connection (damaged/pulled-

out pins, corrosion, etc.).

• Is there any malfunction?

Yes

Repair or replace the terminal, then go to Step 10.

No

Go to the next step.

9

INSPECT PURGE SOLENOID VALVE CONTROL 
CIRCUIT

• Turn ignition switch to the ON position (Engine 

off).

• Measure voltage between purge solenoid valve 

terminal B (harness-side) and body ground.

• Is the voltage B+?

Yes

Repair or replace the wiring harness for a short to power 
supply, then go to the next step.

No

Inspect for continuity between purge solenoid valve 
terminal B (harness-side) and PCM terminal 2AB (harness-
side).

• If there is continuity, go to the next step.

• If there is no continuity, repair or replace the wiring 

harness for an open circuit, then go to the next step.

10

VERIFY TROUBLESHOOTING OF DTC P0443 
COMPLETED

• Make sure to reconnect all disconnected 

connectors.

• Clear the DTC from the PCM memory using 

the M-MDS.

• Turn the ignition switch off.

• Start the engine and warm it up completely.

• Is the PENDING CODE for this DTC present?

Yes

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

No

Go to the next step.

11

VERIFY AFTER REPAIR PROCEDURE

• Perform the “After Repair Procedure”.

 (See01-02-10 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

DTC P0446

Change over valve (COV) (EVAP system leak detection pump) stuck close

DETECTION 

CONDITION

• The PCM monitors the pump load current (EVAP line pressure), while the EVAP leak monitor is operating. 

When the decrease in the pump load current is less than the specification after the reference current value 
has been obtained, the PCM determines that the change over-valve (COV) in the EVAP system leak 
detection pump has a malfunction.

Diagnostic support note

• This is an intermittent monitor (CCM).

• 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.

• DTCs are stored in the PCM memory.

POSSIBLE 

CAUSE

• COV (in EVAP system leak detection pump.) malfunction

• Short to the power circuit between the EVAP system leak detection pump terminal C and PCM terminal 1V

• PCM malfunction

1871-1U-06B(01-02).fm  142 ページ  2006年3月15日 水曜日 午前10時32分

 

 

 

 

 

 

 

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