DTC P0131 [13B-MSP]

id0102g1804600

DTC P0131

A/F sensor circuit low input

DETECTION CONDITION

•  Detect any of the following condition:

―  The input voltage to the A/F sensor positive terminal is 1.128 V or less.

―  The input voltage to the A/F sensor negative terminal is 0.044 V or less.

―  The electric potential difference between the A/F sensor positive and negative terminals is 0 V or less.

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 the first drive cycle.

•  FREEZE FRAME DATA is available.

•  The DTC is stored in the PCM memory.

POSSIBLE CAUSE

•  Connector or terminal malfunction

•  Short to ground in wiring harness between A/F sensor terminal A and PCM terminal 2AD

•  Short to ground in wiring harness between A/F sensor terminal B and PCM terminal 2Z

•  Open circuit in wiring harness between A/F sensor terminal A and PCM terminal 2AD

•  Open circuit in wiring harness between A/F sensor terminal B and PCM terminal 2Z

•  A/F sensor malfunction

•  PCM malfunction

DTC P0131	A/F sensor circuit low input
DETECTION CONDITION	• Detect any of the following condition: ― The input voltage to the A/F sensor positive terminal is 1.128 V or less. ― The input voltage to the A/F sensor negative terminal is 0.044 V or less. ― The electric potential difference between the A/F sensor positive and negative terminals is 0 V or less. 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 the first drive cycle. • FREEZE FRAME DATA is available. • The DTC is stored in the PCM memory.
POSSIBLE CAUSE	• Connector or terminal malfunction • Short to ground in wiring harness between A/F sensor terminal A and PCM terminal 2AD • Short to ground in wiring harness between A/F sensor terminal B and PCM terminal 2Z • Open circuit in wiring harness between A/F sensor terminal A and PCM terminal 2AD • Open circuit in wiring harness between A/F sensor terminal B and PCM terminal 2Z • A/F sensor malfunction • PCM malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED • Have FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS (A/F sensor, HO2S related) been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
2	VERIFY RELATED SERVICE INFORMATION AVAILBAILITY • Verify related Service information availability. • Is any related Service information available?	Yes	Perform repair or diagnosis according to the available Service information. • If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	INSPECT A/F SENSOR CONNECTOR FOR POOR CONNECTION • Turn the ignition switch off. • Disconnect the A/F sensor connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction?	Yes	Repair or replace the terminal, then go to Step 8.
3		No	Go to the next step.
4	INSPECT A/F SENSOR CIRCUIT FOR SHORT TO GROUND • Turn the ignition switch off. • Inspect for continuity between the following circuits: ― A/F sensor terminal A (wiring harness-side) and body ground ― A/F sensor terminal B (wiring harness-side) and body ground • Is there continuity?	Yes	Repair or replace the wiring harness for a possible short to ground, then go to Step 8.
4		No	Go to the next step.
5	INSPECT A/F SENSOR CIRCUIT FOR OPEN CIRCUIT • Turn the ignition switch off. • Inspect for continuity between the following circuits: ― A/F sensor terminal A (wiring harness-side) and PCM terminal 2AD (wiring harness-side) ― A/F sensor terminal B (wiring harness-side) and PCM terminal 2Z (wiring harness-side) • Is there continuity?	Yes	Go to the next step.
5		No	Repair or replace the wiring harness for a possible open circuit, then go to Step 8.
6	INSPECT PCM CONNECTOR FOR POOR CONNECTION • Turn the ignition switch off. • Disconnect the PCM connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction?	Yes	Repair or replace the terminal, then go to Step 8.
6		No	Go to the next step.
7	INSPECT A/F SENSOR • Inspect the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR INSPECTION [13B-MSP].) • Is there any malfunction?	Yes	Replace the A/F sensor, then go to the next step. (See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION [13B-MSP].)
7		No	Go to the next step.
8	VERIFY TROUBLESHOOTING OF DTC P0131 COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the M-MDS. • Perform the DRIVE MODE 03. (See OBD DRIVE MODE [13B-MSP].) • Is the PENDING CODE same as the DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [13B-MSP].)
8		No	Go to the next step.
9	VERIFY AFTER REPAIR PROCEDURE • Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [13B-MSP].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [13B-MSP].)
9		No	DTC troubleshooting completed.