U0173 critical

Lost Communication With Fuel Pump Control Module

The U0173 code means the vehicle's onboard diagnostic system has detected: Lost Communication With Fuel Pump Control Module. This is a critical severity code.

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Keep driving?
No -- stop driving
DIY difficulty
hard
Estimated cost
$250 - $900 (parts and labor)
Diagnose CAN Bus Issues
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Network codes mean modules are not communicating. You need a scanner that reads all systems to find the problem.

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Common Symptoms

  • Engine stalls or will not start
  • Check Engine Light illuminated
  • Long cranking before engine starts
  • Engine loses power intermittently
  • Fuel pressure drops below specification

Probable Causes (Ranked by Likelihood)

  • Failed fuel pump control module Very High
  • Damaged wiring to fuel pump module High
  • Corroded connector at fuel pump assembly Moderate
  • Faulty fuel pump relay Moderate

Step-by-Step Diagnostic Procedure

  1. Check fuel pump relay and fuse in the underhood fuse box

  2. Verify power and ground at the fuel pump control module

  3. Measure fuel pressure at the fuel rail with a gauge

  4. Inspect wiring from module to fuel pump assembly in the tank

  5. Check for CAN bus communication with the fuel pump module

Frequently Asked Questions

Can I drive with code U0173?

No, do not drive. Without proper fuel pump control the engine can stall unexpectedly, creating a dangerous situation especially at highway speeds.

What causes U0173?

Most often a failed fuel pump control module located near or on the fuel tank. Corroded connectors from road exposure are also common on trucks.

Is U0173 expensive to fix?

Repair costs range from $250 to $900. The fuel pump module on trucks often requires dropping the fuel tank which adds to labor costs.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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