Network, generic (extended)

U3009 Control Module Ground B

Check engine lightOn
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

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.

Likely causes

Loose nut or stud at the ground B mounting point
Corroded contact face at the strut tower or body ground
Damaged ground wire B or crimp in the harness

Symptoms

  • Intermittent steering assist or brake warning messages
  • Heavier steering or reduced brake control while the fault is active

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 bground strap

Related codes

U3008U3015U3016U3007

References: gsi.ext.gm.com, static.nhtsa.gov.