Open circuit or high resistance in the pump control wiring or connector, such as corrosion or a pushed-out terminal; Control wire shorted to battery or another voltage supply; Faulty fuel cooler pump with an internal open circuit or failed electronics; Faulty pump relay or a stuck relay contact, where the pump is fed through a relay; Blown fuse or poor supply or earth to the pump circuit; Fault in the control unit output driver; Outdated control unit software where the manufacturer has issued a known correction.

P008E

Fuel Cooler Pump Control Circuit High.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
0: AreaFuel and air metering, auxiliary emission controls
8E: FaultThe specific fault in that area

What it means

P008E means the engine control unit has detected a high voltage on the control circuit for the fuel cooler pump. This pump circulates coolant through a heat exchanger that cools the fuel, usually the return fuel on diesels or the fuel on some direct injection engines. The control unit saw a circuit voltage higher than commanded, which points to a short to voltage, a fault in the driver or relay, or an open circuit in the wiring or pump.

Symptoms

Engine warning light on
Fuel temperature higher than normal, or a fuel temperature related fault logged alongside
Reduced power or limp mode in some cases, depending on the model
Hot start problems or rough running when the fuel is hot
Fuel cooler pump not running, or running constantly (no audible hum)

Possible causes

Open circuit or high resistance in the pump control wiring or connector, such as corrosion or a pushed-out terminallikely
Control wire shorted to battery or another voltage supplylikely
Faulty fuel cooler pump with an internal open circuit or failed electronicslikely
Faulty pump relay or a stuck relay contact, where the pump is fed through a relaypossible
Blown fuse or poor supply or earth to the pump circuitpossible
Fault in the control unit output driverrare
Outdated control unit software where the manufacturer has issued a known correctionrare

How to diagnose

Read all stored and pending codes and the freeze frame data, noting engine temperature, fuel temperature and speed when the code set, and check for related fuel temperature or coolant codes.
Check the pump fuse and relay, and look up the circuit layout for this model, as the pump and control method vary between engines.
Inspect the pump wiring, connector and terminals for chafing, corrosion, water ingress, bent pins or heat damage.
Listen for or feel the pump running, and use a bi-directional scan function, where available, to command the pump on and off.
With the connector disconnected, measure the supply voltage, earth and control signal against the wiring diagram to find a short to voltage, open circuit or poor earth.
Check the wiring resistance and continuity between the control unit and the pump, and test for shorts to voltage.
Test the pump itself, checking its resistance or current draw against the specification for the model.
Check whether a software update applies to this model and engine, if the wiring and pump test good.

How to fix

Repair or replace damaged wiring, connectors or terminals, and clear any corrosion or water ingress.
Repair a short to voltage in the control circuit.
Replace the fuel cooler pump if it fails electrical or running tests.
Replace a faulty relay or fuse, and correct the cause of any blown fuse.
Restore a poor supply or earth connection to the circuit.
Only if all else is good and a known fault exists, update the control unit software or replace the control unit.

Can I keep driving?

Medium severity

The car can usually be driven short distances, but fix it soon because hot fuel can reduce power and put extra strain on the fuel system. Avoid long or heavily loaded journeys, and stop if the car loses power or the fuel temperature warning appears.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.