Network, generic (extended)

U3016 Control Module Ground D

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

U3016 closes the ground series and stands for a fourth return path, D, that the module considers open or out of line with its other grounds. Four grounds on one unit are rare, so before chasing the D pin it pays to check whether grounds A to C are logged as well; several ground codes at once point to a shared splice, the battery negative cable or a body-to-engine strap rather than to one wire. No manufacturer publishes a definition for U3016. GM's ratio check for two brake module grounds (19OBDG03B) and Ford's bulletin 26-2150, which assigns grounds A and B of a steering module to different bolts, show that each letter means a real, separate fastening point. CARB expects electrical faults of such components to be caught by continuous circuit checks.

Likely causes

Poor shared ground, battery negative or engine-to-body strap
Corroded or loose eyelet at ground point D
Damaged ground pin or water in the module connector
Fault in the module's own ground monitoring

Symptoms

  • Warning or service message for the affected system
  • Several ground or supply codes logged at the same time
  • Intermittent loss of the module's function

Repair estimate

DifficultyMediumDIY possible
Parts and labour€10–250
Time0.5–2 h

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

Parts involved

module ground dground strap

Related codes

U3015U3008U3009U3014

References: law.cornell.edu, gsi.ext.gm.com, static.nhtsa.gov.