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Home >> Mazda >> 2017 >> CX-9 Signature >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> On-Board Diagnostic - Engine Control System (1 Of 5) >> DTC P0138-00; Ho2S Circuit High Input >> Notes
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DTC P0138-00; Ho2S Circuit High Input: Notes

NOTE:
  • To determine the malfunctioning part, proceed with the diagnostics from "Function Inspection Using M-MDS".

Details On DTCs

DETECTION CONDITION AND POSSIBLE CAUSE

DESCRIPTION HO2S circuit high input
DETECTION CONDITION Determination conditions
  • A condition in which the HO2S input voltage exceeds the specified value continues for the specified period.
Preconditions
  • Not applicable
Malfunction determination period
  • 5 s period
Drive cycle
  • 2
Self test type
  • CMDTC self test, KOEO self test, KOER self test
Sensor used
  • HO2S
FAIL-SAFE FUNCTION
  • Not applicable
VEHICLE STATUS WHEN DTCs ARE OUTPUT
  • Illuminates check engine light.
POSSIBLE CAUSE
  • HO2S connector or terminals malfunction
  • PCM connector or terminals malfunction
  • Short to power supply in wiring harness between the following terminals:
    • HO2S terminal A-PCM terminal 2AI
      • HO2S terminal B-PCM terminal 2AJ
  • HO2S malfunction
  • PCM malfunction