P2687 indicates an electrical open circuit in the control system for the fuel heater. This component warms diesel fuel to prevent gelling in cold temperatures. The engine control module has detected insufficient voltage or continuity in this circuit.
The dedicated fuse for the fuel heater circuit may have failed due to age or a minor surge.
The heating element inside the fuel filter housing often burns out over time.
Wires near the engine block can melt or break from heat and vibration.
Exposure to fuel and moisture can cause terminal corrosion at the plug.
The control relay supplying power to the heater may have internal contact failure.
Internal driver failure within the control module is possible but statistically uncommon.
The vehicle is drivable, but cold weather starting reliability will be reduced.
No, replacement of the PCM is rarely necessary for this specific circuit fault.
The system performs self-checks at startup regardless of ambient temperature.
Yes, an illuminated check engine light typically results in an emissions test failure.