P008D medium Severity

P008D: Fuel Cooler Pump Control Circuit Low

May cause reduced engine performance, check engine light illumination, and increased fuel temperature; temporary driving is possible but not recommended under heavy load until repaired

Overview

OBD-II code P008D indicates a low voltage condition detected in the fuel cooler pump control circuit on vehicles equipped with a fuel cooling system, commonly in diesel applications.

Common Symptoms

  • Check Engine Light illuminated
  • Decreased engine performance
  • Acceleration or idle surging
  • Increased fuel consumption
  • Unusual noises from fuel cooler pump area

Most Common Causes

Faulty or failed fuel cooler pump high

Pump electrical/mechanical failure can drop circuit voltage triggering the code

Damaged or corroded wiring/connectors in fuel cooler pump control circuit high

Wiring harness issues frequently cause low voltage circuit conditions

Faulty fuel cooler pump relay or blown fuse medium

Loss of power supply to pump control circuit can appear similar to low voltage

Faulty PCM/ECM output or internal control module issue low

Less common but possible, especially if other circuits show abnormalities

Diagnostic Steps

  1. Retrieve P008D and any related codes with a proper scan tool
    Expected: P008D code present, check for related fuel system or electrical codes
    Interpretation: Confirms current fault and potential multiple system involvement
  2. Perform visual inspection of wiring harness/connectors at fuel cooler pump and associated components
    Expected: Wiring intact with no corrosion, fraying, or loose connections
    Interpretation: Damaged wiring/connectors likely cause if abnormalities present
  3. Check fuses and relay for fuel cooler pump circuit
    Expected: Fuses intact, relay clicking and functional
    Interpretation: Replace faulty fuses/relay if not functioning
  4. Measure voltage at fuel cooler pump control circuit with multimeter while key on/run
    Expected: Voltage within manufacturer specification for control circuit
    Interpretation: Low voltage confirms circuit issue; normal voltage points to pump or module fault
  5. Apply direct power to fuel cooler pump to test pump operation
    Expected: Fuel cooler pump runs smoothly at correct supply voltage
    Interpretation: Pump failure likely if it does not run under direct power
  6. If wiring and pump test good, perform PCM control output test per OEM procedure
    Expected: PCM outputs correct control signal
    Interpretation: Incorrect PCM output indicates module issue; consult OEM tech data

Repair Solutions

Replace defective fuel cooler pump medium
Estimated Cost: $300 - $900

Cost varies widely by vehicle application and pump accessibility

Repair or replace damaged wiring and connectors medium
Estimated Cost: $50 - $300

Dependent on extent of wiring damage

Replace faulty fuel cooler pump relay or blown fuse easy
Estimated Cost: $10 - $100

Simple electrical component replacement if found faulty

Repair or reprogram PCM if confirmed faulty hard
Estimated Cost: $400 - $1200

Requires OEM diagnostics and possible programming tools

Common Misdiagnoses

Avoid these common diagnostic mistakes:

  • Assuming pump failure without verifying power/ground to pump circuit
  • Overlooking blown fuse or faulty relay
  • Misinterpreting intermittent wiring resistance as normal

Frequently Asked Questions

Technical definition of P008D OBD-II Code

The P008D code stands for Fuel Cooler Pump Control Circuit Low. This generally indicates an issue with the Fuel System system.

Reflecting on severity: How bad is P008D?

This is a medium priority issue. May cause reduced engine performance, check engine light illumination, and increased fuel temperature; temporary driving is possible but not recommended under heavy load until repaired

How do I know if I have code P008D?

Common symptoms include: Check Engine Light illuminated, Decreased engine performance, Acceleration or idle surging. You might also notice the Check Engine Light is on.

What parts fail when P008D is set?

It can be caused by several factors, most notably: Faulty or failed fuel cooler pump, Damaged or corroded wiring/connectors in fuel cooler pump control circuit, Faulty fuel cooler pump relay or blown fuse.

What is the price difference for fixing P008D?

The cost varies significantly based on the root cause. For example, replacing a Replace faulty fuel cooler pump relay or blown fuse typically costs between $10 and $100, while fixing a Repair or reprogram PCM if confirmed faulty can range from $400 to $1200.

What cars are affected by the P008D code?

P008D is not specific to any one brand. It can appear on Ford, Dodge, Toyota, Honda, Jeep, and other vehicles.

User Comments (0)

Share your experience or ask a question about this code.

Be the first to share your experience with P008D!