DTC P0140:00: Notes

DTC P0140:00 (LF, L5) DETECTION CONDITION AND POSSIBLE CAUSE

DTC P0140:00	HO2S circuit no activity detected
DETECTION CONDITION	The PCM monitors the input voltage from the HO2S when the following conditions are met. Under the following monitoring conditions, if the input voltage from the HO2S does not even exceed 0.6 V though the short term fuel trim is controlled up to 20.5% for 20.8 s , the PCM determines that HO2S circuit is not activated. MONITORING CONDITIONS Drive Mode 03 (EGR System, A/F sensor heater, HO2S heater, A/F sensor, HO2S and TWC Repair Verification Drive Mode) Estimated temperature of the zirconia element inside the HO2S above 450 °C {842 °F) Diagnostic support note This is an intermittent 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 first drive cycle. FREEZE FRAME DATA (Mode 2)/Snapshot data is available. The DTC is stored in the PCM memory.
POSSIBLE CAUSE	HO2S connector or terminals malfunction HO2S heater malfunction Short to ground in wiring harness between HO2S terminal A and PCM terminal 2Q PCM connector or terminals malfunction Leakage exhaust system Open circuit in wiring harness between HO2S terminal A and PCM terminal 2Q Engine malfunction Leakage engine coolant Insufficient engine compression HO2S malfunction PCM malfunction
Courtesy of MAZDA MOTORS CORP.
^1 : Vehicles without advanced keyless entry and push button start system : ^2 : Vehicles with advanced keyless entry and push button start system