5 volt reference

Many sensors use and share a common 5 volt reference signal. Why? and what is it for?

Category:

Autos & Vehicles

Tags:

• volt
• reference
• auto
• repair
• diagnostics
• testing

[ChuddleBuggy]

Hello, sir. Could this 5v reference be the cause of a crank position sensor DTC on a ford 302? If so, does this mean that the pcm itself might need to be replaced if it fails for 'noisy' ckp sensor output?

[fxallen1]

Video running fine this AM.

[universusxxx]

Be aware that many car sensors work on TTL level, so 5V is not only reference but also power and high signal.

[fivefortyeye540i]

Thanks D ! I always wondered exactly what that ment ..

[beefystik]

@blazingtonight1 Cam and Crank sensors emit frequencies that the computer counts, so you pretty much have to have a scope to see what they are 'telling' the computer.

[blackericdenice]

@blazingtonight1 Your cam and crank sensor will have very low volt at idle and will increase as rpm gos up. I THINK.

[Squirrelyone]

Cool to know ..good stuff .!

[blazingtonight1]

So your saying your cam and crank sensor will run off a 5v not a 12 v system ? Another question: if so is the cam and crank producing its own 5v so the pcm or ecm can use it and then determined if it working right? Or is there a resister to turn the 12v into 5v? I ask cause I wounder on how would u test for that or am I just confusing my self and thinking to much

[CoolasIce2]

Good info, but too short.

[DerekLMartin]

I see you have the loadpro test leads connected to your meter. How do you like them?