U0138
System
Network (CAN Bus)
Scanner required
Full-system scanner (engine, ABS, SRS, transmission, service resets)

Lost Communication with Suspension Control Module

Understand U0138, common causes, and the right SEAFLO pump to diagnose it.

Adaptive or air suspension control module offline.

Common symptoms

  • Suspension fault light
  • Vehicle sits low or high
  • Ride harshness

Typical causes

  • Failed suspension module
  • CAN wiring to compressor
  • Air leak causing module shutdown
  • Low voltage

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 U0138 with a basic code reader?
U0138 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 U0138?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.