This code indicates that the engine computer has detected an abnormally high voltage in the electrical circuit that controls the electric coolant pump. It typically means the circuit is experiencing a short to power, a failed internal component, or a lack of ground, preventing the computer from properly regulating the pump.
The pump's internal motor or electronics can short circuit, causing a constant high voltage condition on the control circuit.
The power or signal wire for the pump can chafe against metal or melt against exhaust components, causing a direct short to power.
A corroded, loose, or broken ground connection prevents the circuit from completing, causing a high voltage reading on the control side.
Moisture inside the electrical connector can bridge terminals, causing erroneous high voltage readings on the control circuit.
An internal driver failure within the engine computer can output constant voltage, though this is extremely rare.
It is risky. The electric coolant pump is essential for cooling the engine and turbocharger after shutdown, and for maintaining cabin heat at idle. Driving without it can lead to engine overheating and severe damage.
No, replacing the engine computer is almost never the correct fix for this code. The most common causes are a failed electric coolant pump or damaged wiring. The computer is rarely at fault and should only be considered after all wiring and the pump have been proven functional.
No. The main water pump is typically mechanically driven by the engine's serpentine belt. The pump referenced by this code is usually an electric auxiliary pump used to circulate coolant when the engine is off or operating at low speeds.
The engine computer monitors the voltage on the control circuit. If the wire shorts to a power source, or if the pump internally shorts, the computer sees a high voltage state when it expects the circuit to be low, triggering the code.