DTC Advanced Diagnostics: P0131 (2.0L Engine) (2024 2025)
DTC P0131 : Air Fuel Ratio (A/F) Sensor (Sensor 1) Circuit Low Voltage
General Description
The driver IC for air/fuel ratio (A/F) sensor (sensor 1) is built into the powertrain control module (PCM). The diagnosis data acquired by the driver IC are called up directly by application specific integrated circuit (ASIC) chip and are considered along with the measured values in order to detect faults in the system and the sensor. At the same time, a distinction is made between SPI faults (transmission faults), chip faults (ex. incorrect placement of components or faulty driver IC), short circuits, as well as overloads at the individual pins. If a short to ground in A/F sensor (sensor 1) circuit is detected, the PCM stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 0.5 seconds or more |
| DTC Type | Two drive cycles, MIL on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| 12 volt battery voltage [Battery] | 10.7 V | 16.1 V |
[ ]: HDS Parameter
Malfunction Threshold
The PCM detects a short to ground in A/F sensor (sensor 1) circuit for at least 0.5 seconds.
Possible Cause
The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
- A/F sensor (sensor 1) LAF_VN line short to ground
- A/F sensor (sensor 1) LAF_VG line short to ground
- A/F sensor (sensor 1) LAF_CA line short to ground
- A/F sensor (sensor 1) LAF_CP line short to ground
- A/F sensor (sensor 1) failure
- PCM internal circuit failure
Confirmation Procedure
Operating Condition
Start the engine. Hold the engine speed [Engine Speed] at 3, 000 rpm without load (in neutral) until the radiator fan comes on, then let it idle.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC, the freeze data, and the on-board snapshot are stored.
Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.