Mazda 6 2002, Workshop Manual

Page: 248 / 1248

ON-BOARD DIAGNOSTIC
F–119
F
End Of Sie
DTC P0172
A6E397001084W28
Diagnostic procedure
16 INSPECT VARIABLE VALVE TIMING CONTROL
SYSTEM OPERATION
Note
•
The following test should be performed for
variable valve timing control system. Go to
next step for vehicles without variable valve
timing control system.
•
Inspect variable valve timing control system
operation.
(See
F–239 Variable Valve Timing Control
System Operation Inspection .)
•
Does variable valve timing control system work
properly?
Yes Go to next step.
No Repair or replace malfunctioning part according to variable
valve timing control system inspection results, then go to
Step 18.
17 INSPECT FUEL INJECTOR OPERATION
•
Remove fuel injector.
•
Inspect injector operation.
•
Is fuel injector okay?
Yes Go to next step.
No Replace injector, then go to next step.
18 VERIFY TROUBLESHOOTING OF DTC P0171
COMPLETED
•
Make sure to reconnect all disconnected
connectors.
•
Clear DTC from PCM memory using WDS or
equivalent.
•
Perform KOER self-test.
(See
F–66 KOEO/KOER SELF-TEST .)
•
Is same DTC present?
Yes Replace PCM, then go to next step.
(See F–43 PCM REMOVAL/INSTALLATION .)
No Go to next step.
19 VERIFY AFTER REPAIR PROCEDURE
•
Perform “After Repair Procedure”.
(See
F–66 AFTER REPAIR PROCEDURE .)
•
Is there any DTC present?
Yes Go to applicable DTC troubleshooting.
(See F–67 DTC TABLE .)
No Troubleshooting completed.
STEP INSPECTION ACTION
DTC P0172 Fuel trim system too rich
DETECTION
CONDITION
•
PCM monitors short fuel trim (SHRTFT) and long fuel trim (LONGFT) values during closed loop fuel
control. If fuel trim exceeds preprogrammed criteria, PCM determines that fuel system is too rich.
Diagnostic support note
•
This is a continuous monitor. (FUEL SYSTEM)
•
MIL illuminates if 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 PCM detects the above malfunction condition during first drive cycle.
•
FREEZE FRAME DATA is available.
•
DTC is stored in the PCM memory.
POSSIBLE
CAUSE
•
Misfire
•
Front HO2S deterioration
•
Front HO2S heater malfunction
•
Pressure regulator malfunction
•
Fuel pump malfunction
•
Fuel return hose clogged
•
Purge solenoid valve malfunction
•
Purge solenoid hoses improper connection
•
PCV valve malfunction
STEP INSPECTION ACTION
1 PERFORM DTC CONFIRMATION PROCEDURE
•
Perform DTC CONFIRMATION PROCEDURE.
(See
F–66 DTC CONFIRMATION
PROCEDURE .)
•
Is same DTC present?
Yes Go to next step.
No Intermittent concern exists. Go to INTERMITTENT
CONCERN TROUBLESHOOTING procedure.
(See
F–227 INTERMITTENT CONCERN
TROUBLESHOOTING .)