System Operation

The IC receives a permanent battery voltage supply via a fuse in the RJB (rear junction box). High speed and medium speed CAN (controller area network) buses are also connected to the IC to receive information from other system control modules for IC functions.

The speedometer is driven by high speed CAN signals transmitted by the ABS (anti-lock brake system) control module. The wheel speeds are measured by sensors reading the rotational speed of the wheels from toothed targets on the hubs. The wheel speeds are passed from the sensors to the ABS control module in the form of pulsed signals. The ABS control module converts these signals into a speed output on the high speed CAN to the IC.

The tachometer is driven by an engine speed signal transmitted on the high speed CAN from the ECM (engine control module). The signal is derived from the CKP (crankshaft position) sensor. The signal is received by the IC microprocessor and the output from the microprocessor drives the tachometer.

The Electric Steering Column Lock (ESCL) is connected directly to the IC. The steering wheel switches are also connected directly to the IC via the steering wheel module. Other vehicle sensors are connected to the CJB (central junction box) which processes the signals from the sensors and passes them to the IC on the high speed or medium speed CAN bus. The ambient temperature signal is received by the ECM which processes the signal and passes the information to the IC on the high speed CAN bus.