Instrument Cluster / Carrier: Description and Operation

INSTRUMENT CLUSTER







The instrument cluster is available with either a integrated display (base cluster) or with a message center display (message center cluster). The integrated display and the message center display are 2-line, vacuum fluorescent type displays. Both the base cluster and the message center cluster contain gauges, informational indicators, and warning indicators that are designed to provide the driver with a system status and to alert the driver that certain conditions exist in the vehicle.

The instrument cluster uses both hardwired inputs and messaged inputs to control the gauge and indicator outputs. Other systems that use instrument cluster inputs are the passive anti-theft system (PATS) and stability/traction control.

Messaged Inputs
Module messaging has increased over time and is slowly becoming the standard for sending and receiving information required to operate the instrument cluster. The instrument cluster is a gateway module. As a gateway module, the instrument cluster receives and sends information to other modules over both the high speed controller area network (HS-CAN) and the medium speed controller area network (MS-CAN) that may not necessarily be used for instrument cluster gauge or indicator outputs.

For additional information and a complete list of all module messages along with the message origination sources, refer to Information Bus (Module Communications Network).

Some of the system status and information messages that the instrument cluster requires from other modules to operate the gauges and indicators are as follows:
- Vehicle speed
- Engine rpm
- Engine coolant temperature
- ABS
- Stability/traction control status
- Four wheel drive (4WD)
- Odometer rolling count
- Tire pressure monitoring system (TPMS)
- Supplemental restraint system (SRS)
- Brake fluid level
- Parking brake status
- Electronic throttle control (ETC)

Hardwired Inputs
The instrument cluster requires hardwired inputs from components that are not hardwired to other modules and, therefore, are not on either the HS-CAN or the MS-CAN but are required for specific instrument cluster functions or gateway requirements. The hardwired inputs are provided by the following components:
- Fuel pump module
- PATS transceiver
- Engine oil pressure switch
- Compass module
- Message center switch

Gauges
Gauges provide information to the driver indicating the status of systems. The available gauges are:
- Battery charge (Hybrid only)
- Fuel
- Speedometer
- Tachometer
- Temperature (except Hybrid)

Informational Indicators
Informational indicators provide information to the driver of conditions that exist in the vehicle. The systems that use informational indicators are:
- Anti-theft
- Check fuel cap
- High beam
- Low fuel
- O/D off (except Hybrid)
- Ready light (Hybrid only)
- RH/LH turn
- Speed control

Warning Indicators
Warning indicator lamps provide information to the driver of conditions that could potentially cause personal injury or alter vehicle performance.
- Air bag
- ABS
- Brake
- Charging system
- Door ajar
- Hazard (Hybrid only)
- Low oil pressure
- Malfunction indicator lamp (MIL)
- Overtemp (Hybrid only)
- Safety belt
- TPMS
- Powertrain malfunction (wrench)