What it means
Open circuit at the fuel cooler pump control. The pump that circulates fuel through a cooler (used on diesels and some hot-fuel applications) cannot be driven.
At a glance
- Usually lights the check-engine light
How it works
A fuel cooler pump circulates fuel through a cooler on some diesel and hot-fuel systems. The control module monitors the pump's control circuit and sets P008C when it detects an open path, so the pump may not run when cooling is needed.
Common causes
Most likely first.
- Wiring break or unplugged connector
- Pump motor open
- Pin pushed back out of connector body
Symptoms
- Check engine light on
- Fuel system warning light, if equipped
- Reduced engine performance in hot conditions
How to diagnose it
- Save freeze-frame data and check for related fuel-system codes or a fuel-system warning that appeared with P008C.
- With the ignition off, inspect the fuel cooler pump connector and harness for disconnection, broken wires, damaged insulation, or terminals pushed back in the connector.
- Check the pump circuit fuse and power and ground connections using the vehicle wiring diagram.
- Measure circuit continuity and check the pump motor winding according to the manufacturer's procedure to locate an open circuit.
- If the circuit and pump test correctly, check the control module output and command operation using the manufacturer's diagnostic procedure.
Common fixes
- Reconnect a loose fuel cooler pump connector and secure the harness.
- Repair a broken control-circuit wire or a pushed-back terminal.
- Repair a failed power or ground connection or replace a blown fuse after finding its cause.
- Replace the fuel cooler pump if its motor is open and the circuit is intact.
Can I keep driving?
You can generally drive gently in cool conditions if the engine runs normally, but avoid prolonged heavy load or hot-weather operation because fuel cooling may be unavailable. Stop if performance drops or a fuel-system warning appears.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.