Dtc P0172 - Mazda 6 2002 Workshop Manual

STEP
16 INSPECT VARIABLE VALVE TIMING CONTROL
SYSTEM OPERATION
Note
• The following test should be performed for
variable valve timing control system. Go to
net 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
• Does variable valve timing control system work
properly?
17 INSPECT FUEL INJECTOR OPERATION
• Remove fuel injector.
• Inspect injector operation.
• Is fuel injector okay?
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
• Is same DTC present?
19 VERIFY AFTER REPAIR PROCEDURE
• Perform “After Repair Procedure”.
(See F–66 AFTER REPAIR
• Is there any DTC present?
End Of Sie

DTC P0172

DTC P0172 Fuel trim system too rich
• PCM monitors short fuel trim (SHRTFT) and long fuel trim (LONGFT) values during closed loop fuel
control. If fuel trim eceeds preprogrammed criteria, PCM determines that fuel system is too rich.
Diagnostic support note
• This is a continuous monitor. (FUEL SYSTEM)
DETECTION
• MIL illuminates if PCM detects the above malfunction condition in two consecutive drive cycles or in one
CONDITION
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.
• Misfire
• Front HO2S deterioration
• Front HO2S heater malfunction
• Pressure regulator malfunction
POSSIBLE
• Fuel pump malfunction
CAUSE
• Fuel return hose clogged
• Purge solenoid valve malfunction
• Purge solenoid hoses improper connection
• PCV valve malfunction
Diagnostic procedure
STEP
1 PERFORM DTC CONFIRMATION PROCEDURE
• Perform DTC CONFIRMATION PROCEDURE.
(See F–66 DTC CONFIRMATION
PROCEDURE.)
• Is same DTC present?
ON-BOARD DIAGNOSTIC
INSPECTION
Inspection.)
SELF-TEST.)
PROCEDURE.)
INSPECTION
Yes Go to net step.
No Repair or replace malfunctioning part according to variable
valve timing control system inspection results, then go to
Step 18.
Yes Go to net step.
No Replace injector, then go to net step.
Yes Replace PCM, then go to net step.
(See F–43 PCM REMOVAL/INSTALLATION.)
No Go to net step.
Yes Go to applicable DTC troubleshooting.
(See F–67 DTC TABLE.)
No Troubleshooting completed.
Yes Go to net step.
No Intermittent concern eists. Go to INTERMITTENT
CONCERN TROUBLESHOOTING procedure.
(See F–227 INTERMITTENT CONCERN
TROUBLESHOOTING.)
ACTION
A6E397001084W28
ACTION
F–119
F