Network, generic

U007D Control Module Communication Bus K Off

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

U007D is one of the few late-alphabet bus-off codes with a public trace, all from GM's 2017 full-size trucks and SUVs (Silverado, Sierra, Tahoe, Suburban, Yukon, Escalade). There a serial data gateway module connects many CAN segments, and PIT5586 lists U007D next to U0073, U0078 and a long row of lost-communication codes. GM names two causes: bent, backed-out or loose terminals at gateway connectors X1 and X2, and a microcontroller fault that keeps the gateway powered but silent on every channel. For the latter GM's interim remedy is to pull the gateway's power fuse for a minute (F26DL on trucks, F28DL on SUVs) until a software update is installed, without replacing parts. Complaints range from dead gauges to no crank or start-then-stall.

Likely causes

Bent, backed-out or loose terminals at the gateway connectors
Gateway microcontroller locks up and stops communicating
Damaged wiring on Bus K

Symptoms

  • Instrument cluster gauges dead or fluctuating
  • No crank, no start or stall after starting
  • Radio, climate controls or steering wheel buttons inoperative
  • Numerous lost-communication codes in many modules

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–600
Time0.3–3 h

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

Parts involved

gateway modulebus k wiring

Related codes

U0073U0078U007CU007EU0100

References: static.nhtsa.gov, static.nhtsa.gov, onsemi.com.