Obdaryn

U3009Control Module Ground B

  • Generic OBD-II code · Network
  • Turns on the check-engine light
  • Can trigger limp mode
How the car detects it
U3009 is the counterpart for the second ground path, B. In the GM brake module of 19OBDG03B the same ratio test runs the other way round: if (G1 − G2)/(G1 + G2) drops below −0.9 for 200 ms, ground 2 is judged disconnected, Type A with MIL. Ford's steering module on the 2025–2026 Explorer, Police Interceptor and Aviator shows that B is a different physical point: TSB 26-2150 sends U3009:1B to the right-hand shock tower ground, G103 on the Explorer and G119 on the Aviator, while ground A sits on the frame rail, and the repair there renews the fastening. Because one good ground can carry the module for a while, the fault may come and go with load, heat or moisture. If both U3008 and U3009 appear, check the shared ground circuit and the battery negative first.
What you may notice
  • Intermittent steering assist or brake warning messages
  • Heavier steering or reduced brake control while the fault is active
Likely causes
  • LikelyLoose nut or stud at the ground B mounting point
  • PossibleCorroded contact face at the strut tower or body ground
  • RareDamaged ground wire B or crimp in the harness
Repair
Medium · Often possible to do yourself.Typical cost: €10 – €250

Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.