Instrument Cluster: Operation: Notes

WARNING: This page is about a different car, the 2006 Dodge Sprinter. However, it is still accessible from the selected car via links, so may be relevant.

The ElectroMechanical Instrument Cluster (EMIC) is designed to allow the vehicle operator to monitor the conditions of many of the vehicle components and operating systems. The gauges, meters and indicators in the EMIC provide valuable information about the powertrain, fuel and emissions systems, cooling system, lighting systems, safety systems and many other convenience items. The EMIC is installed in the instrument panel so that all of these monitors can be easily viewed by the vehicle operator when driving, while still allowing relative ease of access for service. The microprocessor-based EMIC hardware and software uses various inputs to control the gauges and indicators visible on the face of the cluster. Some of these inputs are hard wired, but many are in the form of electronic messages that are transmitted by other electronic modules over the Controller Area Network (CAN) data bus network. (Refer to ELECTRONIC CONTROL MODULES ).

The EMIC microprocessor smooths the input data using algorithms to provide gauge readings that are accurate, stable and responsive to operating conditions. These algorithms are designed to provide gauge readings during normal operation that are consistent with customer expectations. However, when abnormal conditions exist such as high coolant temperature, the algorithm can drive the gauge pointer to an extreme position and the microprocessor can sound a chime through the on-board audible tone generator to provide distinct visual and audible indications of a problem to the vehicle operator. The instrument cluster circuitry also provides audible turn signal and hazard warning support by emulating the "ticking" sound associated with a conventional electro-mechanical flasher using a contactless relay. The relay will also provide an indication of a turn signal failure by sounding at double the usual frequency. Each audible warning is provided to the vehicle operator to supplement a visual indication.

The EMIC circuitry operates on battery current received through a non-switched fused B(+) circuit, and on a fused ignition switch output circuit. The EMIC circuitry is grounded through a ground circuit and take out of the frame wire harness with an eyelet terminal connector that is secured to a stud by a nut at a ground location on the dash panel just forward of the instrument cluster. Separate switched ground inputs from the key-in ignition switch and the front door jamb switches provide wake-up signals to the EMIC circuitry. This arrangement allows the EMIC to provide some features regardless of the ignition switch position, while other features will operate only with the ignition switch in the On position.

Proper diagnosis and testing of the EMIC, the CAN data bus, the data bus electronic message inputs to and outputs from the EMIC, as well as the retrieval or erasure of a Diagnostic Trouble Code (DTC) requires the use of a diagnostic scan tool. Refer to BODY DIAGNOSTIC PROCEDURES . See the owner's manual in the vehicle glove box for more information on the features, use and operation of the EMIC.