DTC P0131 [L3]: Notes

DTC P0131 (L3) DETECTION CONDITION & POSSIBLE CAUSES

DTC P0131	A/F sensor circuit low input
DETECTION CONDITION	The PCM monitors the input voltage from the A/F sensor while the engine is running. If any A/F sensor terminal voltage is below 1.2 V for 1 s, the PCM determines that the A/F sensor circuit voltage is low. MONITORING CONDITION Battery voltage: 10-18 V Diagnostic support note This is an continuous monitor (A/F sensor, HO2S). 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 is available. The DTC is stored in the PCM memory.
POSSIBLE CAUSE	A/F sensor Connector or terminal malfunction Short to ground in wiring harness between A/F sensor terminal F and PCM terminal 2Z Short to ground in wiring harness between A/F sensor terminal D and PCM terminal 2AC Short to ground in wiring harness between A/F sensor terminal B and PCM terminal 2AD PCM connector or terminal malfunction Open circuit in wiring harness between A/F sensor terminal F and PCM terminal 2Z Open circuit in wiring harness between A/F sensor terminal D and PCM terminal 2AC Open circuit in wiring harness between A/F sensor terminal B and PCM terminal 2AD A/F sensor malfunction PCM malfunction

DTC P0131

A/F sensor circuit low input

DETECTION CONDITION

The PCM monitors the input voltage from the A/F sensor while the engine is running. If any A/F sensor terminal voltage is below 1.2 V for 1 s, the PCM determines that the A/F sensor circuit voltage is low.

MONITORING CONDITION

Diagnostic support note

This is an continuous monitor (A/F sensor, HO2S).
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 is available.
The DTC is stored in the PCM memory.

POSSIBLE CAUSE

A/F sensor Connector or terminal malfunction
Short to ground in wiring harness between A/F sensor terminal F and PCM terminal 2Z
Short to ground in wiring harness between A/F sensor terminal D and PCM terminal 2AC
Short to ground in wiring harness between A/F sensor terminal B and PCM terminal 2AD
PCM connector or terminal malfunction
Open circuit in wiring harness between A/F sensor terminal F and PCM terminal 2Z
Open circuit in wiring harness between A/F sensor terminal D and PCM terminal 2AC
Open circuit in wiring harness between A/F sensor terminal B and PCM terminal 2AD
A/F sensor malfunction
PCM malfunction