Normal Operation

WARNING: This page is about a different car, the 2010 Mercury Mariner and 2010 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

The Smart Junction Box (SJB) and the Instrument Cluster (IC) communicate using the Medium Speed Controller Area Network (MS-CAN). Messages are exchanged between the modules on the MS-CAN for the purposes of determining what functions are being carried out.

DTC U0155 (Lost Communication with Instrument Panel Cluster (IC ) Control Module) - set by the SJB if IGN status message is present, the SJB supply voltage is greater than 10.5 volts, the ignition must be in the on position for a minimum of 5 seconds and if messages are missing for 15 seconds or longer from the IC over the MS-CAN .

This pinpoint test is intended to diagnose the following:

Module communication
IC
SJB