No Bus Indicator

The no bus indicator gives an indication to the vehicle operator when the IC detects a loss of electronic communication over the CAN data bus. This indicator is controlled by the IC logic circuit based upon programming and electronic messages not being received over the CAN data bus from the BCM.

The no bus indicator function of the electronic display unit is completely controlled by the IC logic circuit, and that logic will only allow this indicator to operate when the IC receives a battery current input on the fused ignition output (run-start) circuit. Therefore, the no bus indication will always be OFF when the ignition switch status is anything except ON or START. The IC will turn ON the no bus indicator for the following reasons:

• No Electronic Communication Messages  - Each time the ignition switch is turned to the ON position and the IC does not receive electronic communication messages over the CAN data bus, the no bus indicator is illuminated. The indicator remains illuminated until CAN bus communication is restored or until the ignition switch status transitions to OFF, whichever occurs first.

The IC continually monitors the CAN data bus to determine the status of many sensors and systems throughout the vehicle. If the IC detects the loss of CAN bus communication it illuminates the no bus indicator to alert the vehicle operator that it cannot provide accurate displays and outputs.

For proper diagnosis of the IC, the CAN data bus or the electronic communication related to no bus indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.