Test Specifications

Pulse transmitter *
a. Resistance between terminals 1 and 2 540 Ohms ± 10%
b. Resistance between terminals 1 and 2 960 Ohms ± 10%

Crankshaft position (TDC) sensor **
a. Resistance between terminals 8 and 10 80 ± 10 Ohms
b. Resistance between terminals 8 and 10 less than 1 Ohm

Ignition coil
Resistance between 1 and 15 0.5 Ohms + 10%
Resistance between 15 and 4 6K Ohms + 10%

High voltage
Resistance across rotor contacts 1000 Ohms ± 20%
Resistance of angled caps at coil and distributor 1000 Ohms ± 20%
Resistance of shielded spark plug connectors 5000 Ohms ± 20%

*Car will have either a or b,
a. Single sensor (at front of engine, with toothed vibration damper).
b. Double sensors (mounted in the bellhousing at the back of engine).

**Car will have either a or b,
a. TDC sensor is mounted above the vibration damper.
b. TDC sensor is attached to the #1 spark plug wire, under the protective cover of the distributor cap.
TDC sensors are wired to the engine diagnostic plug only. (Terminal designations are for the diagnostic plug).

Note; BMW uses solid core wire with screw on resistors at each end. Because of this, all wires should have about the same resistance, regardless of length (compared to carbon core wire in which the resistance increases with the length of the wire).
For additional Motronic information, refer to "Computers and Control Systems", Testing and Inspection