You are just one of the best teachers I have ever had. Thank You so much! Short, and concise!

@realfixesrealfast

4 ай бұрын

you are welcome, glad they help

Imagine a potentiometer with constant 5 volts feeding it from the engine computer. The other end of the pot is grounded back at the Ecm. The wiper is controlled by let's say a throttle and moves along the pot resistor giving corresponding voltages from 0 to 5 volts back through the 3rd wire to the ecm. We are dealing with small voltages here at the ecm so the 5 volt ref must be constant. The computer switches circuits on and off by grounding them which reduces the current and allows for smaller components on the board. Great topic!

You are my best teacher

Always good info. get from you ...thanks kkep it up

Cool to know ..good stuff .!

Good video.

@diesel1dee the 12v in is to the module and then the module sends out the 5 volt reference to the sensor and the sensor sends return voltage on the signal wire

Excellent explanation even in 2020.

love the load prob in the background

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

Realfixesrealfast good evening have a great day and take care Realfixesrealfast Thanks 👍 helpful video From Nick Ayivor from London England UK 🇬🇧

Thanks for the explanation Duane , any chance on a video using the load pro you have sitting on the engine ? Interested in finding out how and why you use it. Thanks much...

Some more info in detail would be great.....

dwayne, what kind of service manual do you use??

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

👍 👍

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

@gagecharlie8448

3 жыл бұрын

A tip : watch series at flixzone. Been using it for watching all kinds of movies recently.

@kolemelvin862

3 жыл бұрын

@Gage Charlie Yea, I have been watching on Flixzone} for since november myself =)

I WONDERED WHAT AND WHY 5 VOLTS. IT SOUNDS SIMPLE THE WAY YOU EXPLAINED IT. I WONDERED WHY 5 VOLTS AND NOT 12V WHEN I CHECKED ASENSOR THX JAY

Short and simple

Good info, but too short.

Video running fine this AM.

I see you have the loadpro

I've never seen 12.0 volts on a fully charged battery. Usually 12.6-12.8 never less unless I have a live load on it.

REALFIXESREALFAST, why is the sensors ground isolated or lifted from the battery ground, they aren't connected why? What is a normal resistance range of a various car sensors?

at the end of the video you say you need a good 12v in"... but don't you mean 5 volts to the sensor and then the sensor gives a reading back and the computer decifers the outcome based on the 2 voltages?

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?

@user-wj9wq7mk4h

2 жыл бұрын

Did you get it figured out?

@gangstalifers-4312

11 ай бұрын

@@user-wj9wq7mk4hprobably not

Hello, I'm trying to investigate a problem in my car that has 2v instead of 5v reference, add I wonder if I can supply 5v from external source in case the problem comes from the PCM? or this reference voltage must come from PCM to function well? Thanks!

@realfixesrealfast

3 ай бұрын

great question. Here is short answer. (assuming 12 volts as standard). 12 volts supplied by battery to the PCM, is reduced by the PCM and supplied as the 5 volt circuit. This is a supplied before load voltage. All loads create a voltage drop. If the 5 volt is reading less, it is either experiencing an unintended voltage drop or what you are viewing is after the load. All DVOM's average and display that average. If your circuit is variable it can be confusing. The best display is a lab scope.

@ShimonBatson

3 ай бұрын

Thanks...

Can you tell me how to fix error code p1639 pontiac grand prix

Is the PCM sending the 5v reference or is it coming from each sensor?

@realfixesrealfast

Жыл бұрын

The 5 volt ref originates in the pcm, it is then routed and sometimes shared by some sensors

@meblake7359

Жыл бұрын

@@realfixesrealfast Is the grounding done by the sensors or the PCM?

@realfixesrealfast

Жыл бұрын

@@meblake7359 the answer depends on the design of the system, the diagram will provide the answer. Some sensors are grounded by being screwed to the engine, and some are 2-wire, 3, or even 4-wire. The "reference" voltage is limited to 5 volts and ground (0) volts to provide an more accurate measurement

@meblake7359

Жыл бұрын

@@realfixesrealfast Well, that makes it more difficult to diagnose without a wiring diagram. Can you use a milliamp test light to see a blinking of the signal from sensor?

@realfixesrealfast

Жыл бұрын

@@meblake7359, it would probably blink but that would not really tell you anything of value. It would be much better to view the signal with a lab scope.

Ok I have 5 volts at sensors but the injectors are not pulsating car won't start so what does that mean that the computer is good??

@strokewarrior5762

3 жыл бұрын

a diagram review would be needed for sure. The injectors usually have 12 volts constantly and the ground is pulsed to make them work. The 5 volts is a shared voltage for monitoring them. The PCM should see the cam signal for timing sequence and the command the injectors on by sending a ground to the injector.

@jasonelliot9633

3 жыл бұрын

@@strokewarrior5762 yes I know all this I have 12 volts at the injectors and the computer is putting out five volts for the sensors one being the tps but no pulse with a noid light and the computer has no communication on the scan tool so because the computer is putting out the 5 volts to the sensors does that mean it's not a wiring problem and the computer is bad? I didn't check every sensor on the 5 volt reference from the computer but I checked 3 and they were right at 5 volts and I don't think its a crank position sensor or cam sensor because the car is getting spark so that means it's getting a signal from those 2 sensors when to spark right??

@realfixesrealfast

3 жыл бұрын

@@jasonelliot9633 No, not really. Of course it is possible but you are not there yet. Remember the PCM is a logic device. It needs inputs, then apply logic, them sends commands. The noid light pulse is a command. So verify the inputs are correct first.

@jasonelliot9633

3 жыл бұрын

@@realfixesrealfast what imputs I don't know what you mean

@jasonelliot9633

3 жыл бұрын

@@realfixesrealfast if you are talking about a crank or cam sensor I seriously doubt that is the problem I have no communication from the computer on a scan tool

L

He is not replying to any body 👎👎👎