Switches, electrically adjustable door mirrors (124)
|
|
Switches, electrically adjustable door mirrors (124)
|
The keypad incorporates the following functions:
|
•
|
Selection of mirror (driver's/passenger)
|
|
•
|
Movement left/right/up/down
|
|
•
|
Tilting of passenger-side door mirror for reversing (mirrors with memory only)
|
|
•
|
Folding in/out of door mirrors (option)
|
The keypad has 2 connection pins and contains 8 resistors connected in series, of which 1 is for diagnosis. When a button is pressed, one or several resistors are bypassed. When none of the buttons are pressed, all the resistors are connected in series.
|
Pin number
|
Signal type
|
Description
|
|
26
|
Ground
|
From DDM
|
|
2
|
5 V feed
|
Via an integrated 2.37 kΩ resistor in the DDM
|
The voltage measured across the pins will depend on which button is pressed. This voltage is converted into a digital value. This digital value is then converted into an identity for the button in question and stored in the control module memory. The value is sent over the bus and is also used by the PDM. The resistor for diagnosis means that there is a closed circuit even when no button is pressed and means that the voltage is never exactly 5 V during normal operation. This means that a DTC can be generated in the event of an open circuit.
