U0073

DTC U0073

Circuit Description

Modules connected to the controller area network (CAN) serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. If no communication is detected on CAN serial data circuit, the DTC is set. A total non communication condition may be caused by a short to battery or voltage on any of the CAN circuits or a short between the CAN high and low circuits.

The following modules communicate on CAN serial data bus:

- The body control module (BCM).
- The electronic brake control module (EBCM), if equipped.
- The engine/powertrain control module (ECM/PCM).
- The transmission control module (TCM), with L61.

DTC Descriptor

This diagnostic procedure supports the following DTC:
- DTC U0073 High Speed CAN Communication Bus.

Conditions for Running the DTC

- Voltage supplied to the modules is in the normal operating voltage range.
- The vehicle power mode requires communication to occur.

Conditions for Setting the DTC

A total non communication condition is detected on CAN serial data circuit.

Conditions for Clearing the MIL/DTC

- A current DTC and MIL clear when the malfunction is no longer present.
- A history DTC clears when requested by the scan tool or when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.