Fuel cooler pump control wiring shorted to ground or chafed; Faulty fuel cooler pump with internal short or seized motor drawing excess current; Corroded, loose or water-damaged connector at the pump or control module; Blown fuse or faulty relay in the pump supply or control circuit; Poor earth or supply voltage fault affecting the circuit; Internal driver fault in the powertrain control module.

P008D

Fuel Cooler Pump Control Circuit Low.

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
8D: FaultThe specific fault in that area

What it means

P008D means the powertrain control module has detected a low voltage condition in the control circuit for the fuel cooler pump. The module commands the pump and monitors the circuit, and the voltage it sees is lower than expected for the commanded state, which points to a short to ground, high resistance or a faulty driver or pump. The fuel cooler pump circulates coolant through a fuel cooler on some engines, mostly diesels and some direct injection petrol engines, so layout and operating conditions vary by model.

Symptoms

Engine warning light on
Fuel temperature higher than normal, or fuel temperature related warnings on some models
Reduced engine power or limp mode on some models
Fuel cooler pump not running or running constantly
Other fuel temperature or cooling system codes stored alongside

Possible causes

Fuel cooler pump control wiring shorted to ground or chafedlikely
Faulty fuel cooler pump with internal short or seized motor drawing excess currentlikely
Corroded, loose or water-damaged connector at the pump or control modulelikely
Blown fuse or faulty relay in the pump supply or control circuitpossible
Poor earth or supply voltage fault affecting the circuitpossible
Internal driver fault in the powertrain control modulerare

How to diagnose

Read all stored codes and freeze frame data, noting any fuel temperature or coolant related codes and the conditions when the fault set
Check the relevant fuses and relay for the fuel cooler pump using the manufacturer wiring diagram, as location varies by model
Inspect the pump wiring, harness routing and connectors for chafing, heat damage, corrosion and water ingress
Command the pump on with a scan tool if supported and listen for or feel it running
Measure the supply voltage and earth at the pump connector with the circuit active
With the connector unplugged and the battery disconnected, test the control wire for a short to ground and for continuity to the module
Check the pump current draw or resistance against manufacturer specifications
If wiring and pump are sound, check the module driver output and look for relevant software updates for that model

How to fix

Repair or replace damaged wiring and fix the cause of the chafing
Clean or replace corroded or damaged connectors and terminals
Replace the fuel cooler pump if it is shorted, seized or out of specification
Replace the faulty fuse or relay after finding why it failed
Repair the supply or earth fault
Repair or replace the control module only after all other causes are ruled out, and update the calibration if an outdated one is a known cause for that model

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but book it in soon because fuel may run hotter than intended and some models reduce power to protect the system. If power drops sharply or temperature warnings appear, stop driving and have it checked.

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