Mazda 2002 6 Workshop Manual page 249

STEP
2 VERIFY RELATED PENDING CODE OR
STORED DTCS
• Turn ignition key to OFF, then ON (Engine
OFF).
• Verify related pending code or stored DTCs.
• Is other DTCs present?
3 IDENTIFY TRIGGER DTC FOR FREEZE FRAME
DATA
• Is DTC P0172 on FREEZE FRAME DATA?
4 VERIFY CURRENT INPUT SIGNAL STATUS
(IGNITION KEY TO ON/IDLE)
• Access ECT, MAF, TP and VSS PIDs using
WDS or equivalent.
• Is there any signal that is far out of
specification when ignition key is ON and
engine runs?
5 VERIFY CURRENT INPUT SIGNAL STATUS
UNDER TROUBLE CONDITION
• Inspect PID data while simulating FREEZE
FRAME DATA condition.
• Is there any input signal which causes drastic
changes?
6 VERIFY CURRENT INPUT SIGNAL STATUS OF
FRONT HO2S
• Access O2S11 PID using WDS or equivalent.
• Verify PID while racing engine (in PARK (ATX)
or NEUTRAL (MTX)).
• Is PID reading okay?
— Above 0.55 V when accelerator pedal is
suddenly depress (rich condition).
— Below 0.55 V just after release of
accelerator pedal (lean condition)
7 INSPECT FUEL LINE PRESSURE
• Turn ignition key to OFF.
• Inspect fuel line pressure while engine running.
(See F–20 FUEL LINE PRESSURE
INSPECTION.)
• Is fuel line pressure okay?
8 INSPECT PURGE SOLENOID VALVE FOR
STUCK OPEN
• Turn ignition key to OFF.
• Disconnect both hoses from purge solenoid
valve.
• Blow air through purge solenoid valve.
• Does air blow through?
9 INSPECT PCV VALVE OPERATION
• Inspect PCV valve operation.
(See F–41 PCV VALVE
• Is PCV valve okay?
10 VERIFY TROUBLESHOOTING OF DTC P0172
COMPLETED
• Make sure to reconnect all disconnected
connectors.
• Turn ignition key to ON (Engine OFF).
• Clear DTC from memory using WDS or
equivalent.
• Perform KOER self-test.
(See F–66 KOEO/KOER
• Is same DTC present?
11 VERIFY AFTER REPAIR PROCEDURE
• Perform "After Repair Procedure".
(See F–66 AFTER REPAIR
• Is there any DTC present?
End Of Sie
F–120
ON-BOARD DIAGNOSTIC
INSPECTION
INSPECTION.)
SELF-TEST.)
PROCEDURE.)
Yes Go to appropriate DTC troubleshooting procedures.
No If drive ability concern is present, go to Step 8.
If not, go to next step.
Yes Go to next step.
No Go to troubleshooting procedures for DTC on FREEZE
FRAME DATA.
Yes Inspect suspected sensor and excessive resistance in
related wiring harnesses. Repair or replace if necessary.
Then go to Step 10.
No Go to next step.
Yes Inspect suspected sensor and related wiring harnesses,
and repair or replace it. Then go to Step 10.
No Go to next step.
Yes Go to next step.
No Replace suspected front HO2S.
Then go to Step 10.
Yes Go to next step.
No Replace fuel pump unit, then go to Step 10.
Yes Replace purge solenoid valve.
Then go to Step 10.
No Go to next step.
Yes Go to next step.
No Replace PCV valve, then go to next step.
Yes Replace PCM, then go to next step.
(See F–43 PCM REMOVAL/INSTALLATION.)
No Go to next step.
Yes Go to applicable DTC troubleshooting.
(See F–67 DTC TABLE.)
No Troubleshooting completed.
ACTION