Instrument Panel Cluster (IPC) Opel Astra H

The IPC (Instrument Panel Cluster - instrument cluster) is the driver's display. Engine speed, vehicle speed and fuel gauge are displayed here. In addition, the IPC contains LEDs for displaying various functions or faults. If the vehicle is fitted with AT/MTA, the IPC will contain a 2 digit display to indicate which gear is engaged. Another LCD display shows the mileage. This display can also show other information (e.g. mileage remaining till next service). The IPC receives all this information via the LS CAN bus

The vehicle speed is recorded by means of the ABS wheel speed sensors. The ABS control unit reads the rotational speeds of the individual wheels and transmits this on the HS bus. The value of the front left wheel speed sensor is used to calculate the vehicle speed. For this, the ECM evaluates the bus message from the ABS and calculates the vehicle speed. This value is then transmitted by the ECM on the HS bus, is transferred by the CIM and forwarded on the LS bus. Here, it is evaluated by the IPC to display the vehicle speed.

Information on distance covered is also recorded by means of the ABS wheel speed sensors. For this purpose, however, the signal from the rear left wheel is used. This value is also calculated first by the ECM, transmitted on the HS CAN and transferred by the CIM onto the LS CAN. This value is used by the IPC to display the mileage.

As the conversion of wheel speeds into vehicle speed or distance is done in the ECM, a tyre circumference must be programmed in here in order to get the correct value for display.

• Service: After replacing the tyres, the ECM must be re-programmed using TECH 2.

If the front left wheel speed sensor, used for the vehicle speed display, should fail, the ECM uses the signal from the front right sensor instead. The same applies for the rear sensors.

Another task of the IPC is to read the statuses of the various sensors and switches and to transmit these on the CAN bus or actuate various actuators by means of bus messages:

Inputs:

Some of the buttons/ switches are fitted with monitoring resistors, so that open circuits can be detected.

Note. The controller for adjusting the height of the headlamps is hard-wired and is not read by the IPC.

Inputs:

• Light switch centre with position light switch, dipped beam switch, front fog lamps switch, rear fog lamps switch, automatic lighting control switch, controller for brightness of instrument panel illumination.
• Hazard warning system button
• Heated rear window button (manual air conditioning MCP / no air conditioning MH)
• Park Assist button
• Central locking button
• Semi-active chassis (SADS) button

Outputs:

• Control indicator for hazard warning system button (background lighting and display function share one LED; PWM controlled). The display is actuated when a corresponding bus message is received from the REC.
• Instrument panel bulb brightness (PWM), controls the brightness of the bulb for the cigarette lighter
• Instrument panel LED brightness (PWM), controls the brightness of the illumination of all buttons/switches in the instrument panel
• Control indicator for heated rear window button. This LED is actuated if the message that the heated rear window is on is received by the REC via the CAN. (Version with manual air conditioning MCP / no air conditioning MH)
• Control indicator for Park Assist button. This LED is actuated if the message that the Park Assist is on has been received from the PAS via the CAN.

Heated Rear Window / Heated Exterior Mirrors Function

The IPC is function master for the "Heated rear window / exterior mirrors" function.

If the IPC receives a request to activate the heated rear window / exterior mirrors (either from the button in the instrument panel or by a bus message from the ECC), the activation conditions are checked. If these are met, the IPC sends the request to activate the heated rear window to the REC. There, the respective relay is switched. If there is feedback from the REC that the heated rear window has been switched on, the LED in the button is activated (MCP / MH) or a bus message to switch on the LED in the ECC control panel is sent (ECC).

Pin Assignment - IPC