S4 Sedan L5-2226cc 2.22L DOHC Turbo (AAN) (1992)
Engine Control Module: Description and Operation
Engine Speed Signal
The Engine Speed Signal is connected to pin 40 of the Motronic control module, the signal is directional OUT only (PIN 40 - OUTPUT ONLY).
The engine speed signal is produced from information supplied to the control module by the engine speed sensor. This signal is used by the tachometer
for display of engine speed in rpm's.