OBD Guide

U172A

Left High Beam Control Module Lost Communication With Left Headlamp Horizontal Motor

U172A is an OBD-II diagnostic trouble code meaning: Left High Beam Control Module Lost Communication With Left Headlamp Horizontal Motor. Common causes: open or short circuit in control circuit, malfunction of the headlight adjustment motor. Estimated repair cost: $17–89.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–89 (est.)

Symptoms

  • Left headlight horizontal adjustment not working
  • Error message on the dashboard
  • Headlights can remain in one position
  • Possible problems with automatic light adjustment

Causes

  • Open or short circuit in control circuit
  • Malfunction of the headlight adjustment motor
  • Wiring Harness Problems
  • Low beam control module malfunction
  • Poor contact in connectors

How to Fix

  1. Check the integrity of the engine control circuit
  2. Inspect connectors and contacts for corrosion
  3. Check the operation of the adjustment motor
  4. Scan the control module for other errors
  5. If necessary, replace faulty components

Related codes

FAQ

What does the U172A code mean?

U172A is an OBD-II diagnostic trouble code that indicates: Left High Beam Control Module Lost Communication With Left Headlamp Horizontal Motor

What causes a U172A error code?

The most common causes of U172A include: Open or short circuit in control circuit; Malfunction of the headlight adjustment motor; Wiring Harness Problems; Low beam control module malfunction.

How do I fix a U172A diagnostic trouble code?

To fix U172A: Check the integrity of the engine control circuit. Inspect connectors and contacts for corrosion. Check the operation of the adjustment motor. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U172A?

Yes, but get it checked soon

How much does it cost to fix U172A?

The estimated repair cost for U172A is $17–89. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat