DTC Advanced Diagnostics: P0687 (2.0L Engine) (2024 2025)
DTC P0687 : Air Fuel Ratio (A/F) Sensor (Sensor 1) Heater Power Source Circuit Short to Power
General Description
A heater for the sensor element is embedded in the air/fuel ratio (A/F) sensor (sensor 1), and it is controlled and monitored by the powertrain control module (PCM). It is activated and heats the sensor to stabilize and speed up the detection of oxygen content when the exhaust gas temperature is cold. If the FI_SUB_RLY_CL- current is a specified range, the PCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 0.3 seconds or more |
| DTC Type | Two drive cycles, MIL on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| 12 volt battery voltage [Battery] | 8 V | 16 V |
| Vehicle | ON mode | |
| Command to A/F sensor (sensor 1) heater relay | ON | |
[ ]: HDS Parameter
Malfunction Threshold
The FI_SUB_RLY_CL- current is greater than 2 A.
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.
- PGM-FI subrelay FI_SUB_RLY_CL- line short to power
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.