What color are pins 67 and 68 at the ECU on Motronic 3.1?

[Jon K]

Hey, winfred, anyone, what colors are the wires that go to pins 67 and 68 on a '92 Bosch Motronic 3.1 non vanos ECU? I want to tap them but I really don't feel like tearing apart the ECU connector again... though I may have to.

[Javier]

Would you like me to e-mail you the pdf for 3.1 M50 1992 external wiring?

Javier

Edit: Tap on them, are you sure? If not taken with a high impedance method, signal may result useless. CPS is a magnetic pickup biased from the ECU 5Vdc, and a low impedance metering circuit may attenuate the output pulses to unacceptable levels.

[Jon K]

Would you like me to e-mail you the pdf for 3.1 M50 1992 external wiring?

Javier

No I think i have the digram I was just not sure. Does your source say which is positive and which is negative?

[Javier]

Javier

[Jon K]

Javier

Wait a minute...

don't you mean AC voltage?

[Javier]

Javier

[Jon K]

Righ tbut it should be AC

[Javier]

it is not a sine wave, nor constant frequency, but if you measure it with a high impedance tester, you will find an AC reading superimposed in a DC reading. The DC reading is useless, only biasing of the circuit, the AC signal is formed by a sequence of pulses following the teeth in the Crankshaft damper.

Javier