The instrument cluster serves as the primary interface
between the driver and the vehicle. The instrument cluster includes the following
components:
| • | Driver Information Center (DIC) |
In addition, the instrument cluster communicates with other major electronic
components over a class 2 serial data line.
The instrument cluster used in this vehicle is either a base type or
an uplevel type (UB7). The instrument cluster contains the following functions:
| • | Engine RPM (Tachometer) |
| • | Driver Information Center (DIC) Display (W/UB7) including Warning/Status
Messages |
| • | Head Up Display (HUD) Interface (W/UA6) |
| • | Warning/Status Indicators |
The instrument cluster has the capability to diagnose malfunctions in
the following components:
| • | The instrument cluster sensors |
| • | The instrument cluster components |
| • | The instrument cluster systems |
When the instrument cluster or another microprocessor-controlled module
detects a malfunction, one of the following actions may occur in order to
alert the driver:
| • | An instrument cluster indicator turns on. |
| • | The driver information center (DIC) displays a message. |
Some indicator lamps and the instrument cluster messages have dual controls.
Base and Uplevel (UB7) Instrument Clusters
Both types of instrument clusters are discussed in this description,
followed by parameters specific to the base and uplevel instrument cluster.
The base and uplevel instrument clusters are not interchangeable. Replace
an instrument cluster only with an instrument cluster of the same type.
Instrument Cluster Functions
The instrument cluster contains a microprocessor which performs the
following functions:
| • | Recognizes operational malfunctions |
| • | Alerts the driver through indicators or DIC messages |
| • | Stores DTCs which identify malfunctions for the technician |
In order to perform all of these functions, the instrument cluster microprocessor
has the following items:
Instrument Cluster Keep Alive Memory (KAM)
The instrument cluster contains a data storage area. The data storage
area saves data when the ignition switch is turned off. The data is lost when
the battery power is removed. The data storage area is called Keep Alive
Memory (KAM). The instrument cluster uses the Keep Alive Memory (KAM) in
order to store the following information:
| • | Trip odometer information |
The KAM area is an integral part of the instrument cluster microprocessor.
The KAM cannot be serviced separately.
Instrument Cluster EEPROM
The instrument cluster contains a data storage area. The data storage
area saves data even when battery power is removed. The data storage area
is referred to as the Electrically Erasable Programmable Read Only Memory
(EEPROM). The instrument cluster uses the EEPROM in order to store the following
information:
| • | Manufacturing information |
The EEPROM area is an integral part of the instrument cluster microprocessor.
The EEPROM cannot be serviced separately.
