Instrument Cluster (IPC) Overview

The IPC serves as the primary vehicle interface for the driver. The IPC used in the vehicle consists of a digital IPC or an analog IPC. Both IPC versions contain similar functions. These functions permit the driver to monitor the operation and/or to control the various vehicle systems.

Both of the IPCs have the capability in order to detect various malfunctions in the following components:
^ The sensors
^ The input switches
^ The components and systems with which the IPC communicates

When the PC (or another micro processor-controlled module) detects a malfunction, one of the following actions may occur:
^ An PC indicator is activated.
^ A message is displayed on the driver message center.
^ A DTC is set in the IPC (or another module's) memory.

Some DTCs may not cause an IPC message to be displayed or activate an IPC indicator lamp.

The PC indicators and messages are activated in order to alert the driver that a system malfunction was detected.

The DTCs are activated in order to ensure that a qualified technician may identify and diagnose a system malfunction.

This vehicle allows the technician to display various input and output parameters and to any set DTCs using one of the following methods:
1. Enter the vehicle diagnostic system. Display the information on the IPC driver message center. Refer to A Diagnostic System Check - Instrument Cluster.
2. Connect a Scan Tool to the DLC.

The Scan Tool is the preferred tool for PC diagnosis. The IPC communicates with the following modules over the Class 2 serial data line:
^ The body control module (PZM)
^ The cellular telephone module (PHN)
^ The climate control panel (CCP)
^ The data link connector (DLC)
^ The electronic brake and traction control module (EBTCM)
^ The heater and A/C programmer (ACM)
^ The integrated radio chassis (IRC)
^ The inflatable restraint sensing and diagnostic module (SDM)
^ The memory mirror module (MMM)
^ The memory seat module (MSM)
^ The powertrain control module (PCM)
^ The road sensing suspension (RSS) (optional)

IMPORTANT: The following microprocessors may not be serviced separately:

^ The electrically erasable programmable read only memory (EEPROM) microprocessor that saves critical data even when the battery power is removed. This microprocessor stores the following settings:
^ The odometer readings
^ The options settings
^ The manufacturing information
^ The vehicle identification number (VIN)
^ The flash EPROM microprocessor that contains a software program used by the IPC in order to monitor, control, and display the various vehicle parameters. The EPROM retains all of the program data if the battery power is removed.