U0118
System
Network (CAN Bus)
Scanner required
Full-system scanner (engine, ABS, SRS, transmission, service resets)

Lost Communication with Fuel Injector Control Module

Understand U0118, common causes, and the right SEAFLO pump to diagnose it.

Fuel injector control module not communicating — common on diesel with separate FICM.

Common symptoms

  • No-start on diesel
  • Rough running
  • Multiple injector-related codes

Typical causes

  • Failed FICM
  • CAN wiring in engine bay
  • Low voltage during crank
  • Corrosion at FICM connector

What scanner do you need?

Full-system scanner (engine, ABS, SRS, transmission, service resets)

Use live data and freeze frame to confirm the fault before replacing parts. ABS, SRS, and network U-codes usually require a full-system scanner.

Diagnostic tips

  • Record freeze frame data when the code first sets
  • Clear the code only after fixing the root cause
  • Check for related pending codes that point to a common issue
  • Verify battery voltage is above 12.4V before chasing sensor codes

Frequently asked questions

Can I diagnose U0118 with a basic code reader?
U0118 may set in the engine module, but related diagnostics often benefit from an enhanced or full-system scanner with live data and freeze frame.
Is it safe to drive with U0118?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.