LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mazda >> 2008 >> 5 Touring, 2.3 L >> Repair and Diagnosis >> Engine Performance >> System >> On-Board Diagnostic [Engine Control System L3) >> DTC P2243 [L3] >> Notes
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC P2243 [L3]: Notes

DTC P2243 [L3] DETECTION CONDITIONS AND POSSIBLE CAUSES

DTC P2243 Front HO2S reference voltage circuit open
DETECTION CONDITION 
  • The PCM monitors the front HO2S signal voltage at PCM terminal 2Z. If the either of the following condition is met, the PCM determines that the front HO2S reference voltage circuit is open.
    • The PCM terminal 2Z voltage is specifed voltage or more for 5s  .
    • PCM detects DTC P0134 or P0030 while the pending code P2243 is stored.

MONITORING CONDITIONS 
  • HO2S heater, HO2S, and TWC verification drive mode
  • Following conditions are met
    • Engine is running or ignition switch is ON position
    • Battery voltage is 10-18 V
    • Front HO2S element impedance below 220 ohms

Diagnostic support note 
  • This is a continuous monitor (HO2S).
  • The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycle 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 is available.
  • DTC is stored in PCM memory.
POSSIBLE CAUSE 
  • Open circuit between front HO2S terminal F and PCM terminal 2Z
  • Short to power supply circuit between front HO2S terminal F and PCM terminal 2Z
  • Front HO2S malfunction
  • PCM malfunction
G05542991