Network, generic

U0076 Control Module Communication Bus D Off

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

GM is the main public user of U0076. In the 2019 tables for the Corvette LT5 engine, Bus D is the Powertrain Sensor CAN, a private link between the ECM and engine-side devices. The ECM sets the code when that bus has been off for one second after the controller has run for three seconds, Type B with MIL after two trips, and holds back its lost-message check toward the fuel level module meanwhile. On the 2020-22 Malibu 1.5 L, bulletin 21-NA-186 traces U0076 together with U18A2 and message counter faults to an ECM harness rubbing on its bracket; owners notice a Service Engine Soon lamp or an erratic fuel gauge. Unlike U0055, which describes the bus D wiring as a whole, this code reports that the ECM's own controller has fallen silent.

Likely causes

ECM harness rubbing through on its bracket
Poor contact at a connector of the engine-side sensor bus
Faulty CAN transceiver inside the ECM

Symptoms

  • Service Engine Soon lamp or MIL on
  • Fuel gauge erratic or wrong
  • Message counter codes stored alongside

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–600
Time0.5–3 h

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

Parts involved

bus d wiringcan transceiver

Related codes

U0055U0075U0077U0073

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