300E 4MATIC (124.230) L6-3.0L (103.985) (1990)
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Postion Sensor Oscilloscope Pattern
t1 = First Segment
t2 = Second Segment
d = Period for one crankshaft rotation
The crankshaft position is recognized from the voltage signals which are produced. The segment front edge generates a negative voltage signal. The
segment rear edge generates a positive voltage signal. Engine speed is determined by measuring the period (d) which is equal to one crankshaft
revolution.
The alternating voltage of the position sensor is passed along the control lead (coaxial lead) to terminal 7 at the ignition control module. the lead is a
single-core cable and the screening is used as a second lead.
If the control module does not receive a signal from the position sensor, the complete ignition system is inoperative, e.g. an interuption of the sensor
coil can cause this.
No TD signal exists if a short to ground is present at the equipment or at the diagnostic connector terminal block terminal TD (X11). to locate the
problem, detach the single wire connection at the (X11) connector. Rectify short to ground in the prospective circuit.
The following components have a TD connection: Tachometer,CFI control module,fuel pump relay and compressor cutoff control module.
