LEMON Manuals: Even more car manuals for everyone
Home >> Mazda >> 2009 >> MX-5 Miata Touring, Standard >> Repair and Diagnosis >> Engine Performance >> System >> On-Board Diagnostic [Engine Control System LF 2.0L) >> DTC P0138 [LF] >> Notes

DTC P0138 [LF]: Notes

DTC P0138 (LF) DETECTION CONDITION AND POSSIBLE CAUSE

DTC P0138 HO2S circuit high input
DETECTION CONDITION 
  • The PCM monitors input voltage from the HO2S. If the input voltage from the HO2S is above 1.2 V  or HO2S bias voltage above 1.8 V  , the PCM determines that the HO2S circuit input is high.

Diagnostic support note 
  • This is a continuous monitor (A/F sensor, HO2S).
  • The MIL illuminates if the 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 the PCM detects the above malfunction condition during the first drive cycle.
  • FREEZE FRAME DATA (Mode 2/Mode 12) is available.
  • The DTC is stored in the PCM memory.
POSSIBLE CAUSE 
  • HO2S connector or terminals malfunction
  • PCM connector or terminals malfunction
  • Short to power supply in wiring harness between HO2S terminal A and PCM terminal 2Q
  • HO2S malfunction
  • PCM malfunction
G06149974Courtesy of MAZDA MOTORS CORP.
scientia non olet · About LEMON Manuals