HomeTrouble CodesU0076

U0076 — Control Module Communication Bus D Off

Generic OBD-II · all makesNetwork / communication

U0076 indicates that the vehicle's control network (CAN Bus D) has lost communication with one of the control modules. The PCM detects that messages from the designated module are not being received.

Symptoms

What causes it — most likely first

1. Loose or corroded Bus D connector

A poor electrical connection at the module's plug or at the bus termination can interrupt data flow.

2. Damaged wiring harness on Bus D

Chafed, broken, or exposed wires along the bus can cause intermittent or complete loss of communication.

3. Blown fuse for Bus D

A blown fuse removes power to the network, resulting in a total loss of messages from the affected module.

4. Faulty control module on Bus D

The module itself may develop an internal fault that stops it from transmitting or receiving data.

5. PCM communication interface failure

A failure of the PCM's network interface is possible but uncommon; it is typically considered only after wiring and module checks.

How it's diagnosed

  1. Inspect the Bus D connector for corrosion, bent pins, or loose locking tabs.
  2. Verify the fuse associated with the network and replace it if blown.
  3. Perform continuity and resistance tests on the Bus D wiring harness.
  4. Scan for additional network codes to identify other affected modules.
  5. Test or replace the suspect control module before considering PCM replacement.

Code facts & related codes

SystemNetwork / communication
StandardizationSAE generic — identical on every make

Frequently asked

Does U0076 always mean the PCM needs replacement?

No, it most often points to a wiring or connector issue; PCM replacement is rarely required.

Can I drive the vehicle with this code?

The vehicle may still operate, but the affected module could be inoperative; driving is generally safe until repaired.

How long does diagnosing U0076 usually take?

A visual inspection and basic electrical tests can be completed in 30‑60 minutes; more extensive testing may take longer.

Will clearing the code fix the problem?

Clearing the code without repairing the underlying fault will cause it to return when the communication loss recurs.