Lost Communication With Restraints Dimming Sensor Module
The U0171 code means the vehicle's onboard diagnostic system has detected: Lost Communication With Restraints Dimming Sensor Module. This is a low severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- $100 - $350 (parts and labor)
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
- Airbag warning light may illuminate
- Dashboard dimming function inoperative
- Automatic brightness control not working
- Headlight auto-dim feature disabled
- Interior lighting does not adjust automatically
Probable Causes (Ranked by Likelihood)
- Failed dimming sensor module on dashboard Very High
- Damaged wiring to sensor on windshield High
- Windshield replacement disrupted sensor connection Moderate
- Module software fault requiring update Low
Step-by-Step Diagnostic Procedure
-
Check the light sensor on the dashboard near the windshield
-
Inspect wiring from sensor to body control module
-
Verify the sensor was reconnected after any windshield work
-
Check for related body control module codes
-
Test sensor response with a flashlight and scan tool live data
Frequently Asked Questions
Can I drive with code U0171?
Yes, safe to drive. The automatic dimming and brightness features will not work but you can manually adjust settings.
What causes U0171?
Often caused by a failed sensor or disrupted connection after a windshield replacement. The sensor is located near the top of the windshield.
Is U0171 expensive to fix?
Usually $100 to $350. If the sensor was just disconnected during windshield work, reconnecting it is often a quick and inexpensive fix.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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