Network, generic

U046A Invalid Data Received From Sunroof Control Module

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U046A is logged when a module, usually the body controller or the overhead console, gets data from the sunroof control module that fails its checks: position and motion reports that contradict each other, a counter that stops changing or a bad checksum. The sunroof module drives the glass panel and sun blind and tracks their end positions. US standard FMVSS 118 restricts when a power-operated roof panel may close and demands automatic reversal where it closes outside those conditions, so a receiver that cannot trust the module usually blocks convenience closing from the key fob or rain sensor. No manufacturer documents U046A publicly. U0169 means the module is silent, U0140 concerns the body control module. Besides connectors, water from blocked roof drains is a plausible cause. The roof may ignore its switch; no MIL.

Likely causes

Water in the roof module or its connector from blocked sunroof drains
Lost end-position learning after battery disconnection or panel work
Chafed wiring or loose connector in the headliner
Internal fault in the sunroof control module

Symptoms

  • Sunroof does not open or close with its switch
  • Convenience closing by key or rain sensor no longer works
  • Panel stops midway or reverses unexpectedly

Repair estimate

DifficultyMediumDIY possible
Parts and labour€0–600
Time0.3–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

sunroof module

Related codes

U0169U0140

References: law.cornell.edu, en.wikipedia.org, autosar.org.