Dtc P0031 - Mazda 2002 6 Workshop Manual

STEP
7 VERIFY TROUBLESHOOTING OF DTC P0012
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?
8 VERIFY AFTER REPAIR PROCEDURE
• Perform "After Repair Procedure".
(See F–66 AFTER REPAIR
• Is there any DTC present?
End Of Sie

DTC P0031

DTC P0031 Front HO2S heater circuit low input
• PCM monitors front HO2S heater control signal at PCM terminal 4A. If PCM turns front HO2S heater off but
front HO2S heater circuit has low voltage, PCM determines that front HO2S heater circuit has malfunction.
Note
• Front HO2S heater is controlled by duty signal.
DETECTION
Diagnostic support note
CONDITION
• This is a continuous monitor (O
• MIL illuminates if PCM detects above malfunction condition in two consecutive drive cycles or in one drive
cycle while DTC for the same malfunction has been stored in PCM.
• PENDING CODE is available if PCM detects above malfunction condition during first drive cycle.
• FREEZE FRAME DATA is available.
• DTC is stored in PCM memory.
• Front HO2S malfunction
• Open circuit between ignition switch and front HO2S terminal C
• Open circuit between front HO2S terminal D and PCM terminal 4A
POSSIBLE
• Short to ground circuit between front HO2S terminal D and PCM terminal 4A
CAUSE
• Poor connection at front HO2S or PCM connector
• PCM malfunction
F–74
ON-BOARD DIAGNOSTIC
INSPECTION
SELF-TEST.)
PROCEDURE.)
sensor heater).
2
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
A6E397001084W04