Greetings,

I have a question which needs answering and I was directed to query you guys on the matter. I need to know how the signal from the rpm sensor is outputted to the ecu and/or tachometer from 0-9000rpm. I am looking for a value expressed in volts or milliamps. Could you help me with my dilemma or direct me in finding this out for myself?

 

Any feedback signal I have ever heard of is in volts.

 

Take a voltmeter and test, I'm guessing 12 volt signal.

Amps and voltage are very different things, if you're hooking up a device to monitor the rpms, make sure it draws very small amount of amps. You can do damage to the ecu if it's a amp hog.

 

It's most likely a pulsed signal. The sensor will send one pulse per revolution to the ecu. Crank the car and see if the meter flashes. Your best bet, for using the signal to drive another circuit, would be to use an optical isolator.

 

The RPM signal is generated from the Crank sensor. The sensor is a Hal effect sensor. The sensor has three wires, 5 volt referance, a ground and the signal. The signal is 0 volts and steps to 5volts. It creates a step pattern. The sensor generates more than one step per revolution, so the actual RPM has to be calulated.

Amps and Volts are related and differant. There is always both.

 

Stratocaster you are a genius. That is exactly the answer I was looking for and appreciate the help very much. Reason I asked if it was milli amps or volts is because I can read either output, I just need to know the values if that makes sense.