i'm at my last session in cegep (here it's between high school and university) and i'll do an OBD scanner that would identify the problem, where is located that problem, what are the level of danger and what may need to be changed that will be datalogged and shown on a screen, for my final project.

the purpose of this topic is that I would need some infos about the sensor used in any honda engine.

what I would need as infos are, it would be for a OBD-2:
- what are the sensors giving to the ECU ( I know they don't all give the same thing, some are 0-5V, others pulses,... but that's what I need to know)
- what are the limits of those sensors, like if the O2 sensor is giving 5V, maybe it's because it's broken, that would help me to know if their's a way to identify if their's really a problem or it's just the sensor that is bugged.

i need a lot more than that, but thoses infos seems to be difficult to find since I don't really know where to search

so if anyone can give me a hint on where to search, like a URL or a book that would help me a lot

 

You can get a book from Napa, i believe its called specifications, its a yellow book. It has all sensors for every import and domestic car and has the specifications for each sensor. I will double check the name and author of the book at work tomorrow.

 

ok perfect, and if you can tell me where can I order this book that would be even more awesome!!

 

I sent you an email with a 8meg attachment. It should be a goldmine of info for your project. It has been awhile since I have went through it though, I don't remember about voltage specs...but nonetheless it should be helpful.

Good luck

 

Ready here's some info cause I'm really boared. You were right most sensors are 5 volt refrences but some are not, some are voltage generators. Common 5v reference sensors are: tps, cts, map, maf, iat, and a hole bunch of others. How these sensors work is they recieve a 5v reference voltage from the ecu or pcm ,or whatever the manufacture calls the computer. Inside the sensor is some type of resistor. To use the coolant temp sensor (cts) for example, this uses a negative temperature coefficient (ntc) resistor. that means the resistor inside the sensor changes its resistance with temp. In a ntc type of resistor as temperature goes up resistance goes down. Whats that mean you ask? Well along with the five volt reference there is usually two other wires that go to any given sensor. One of these wires is ground the other is the return. The return is the one were focusing on. After the 5 v reference goes to the sensor it passes through the resistor. the resistance in ohms of that sensor then uses up voltage, the amount left over is then sent through the return line to the ecu to be interprited and used in the logic tables of the computer. Thats the simplest way I can explain it.

Sensors like the O2 and knock though are not 5v reference, I repeat are not reference. These are voltage generators. For an explaination of these do a Yahoo search cause Im done typing. You could actually do a search on any sensor because I'm sure you'll get like 1000 different sites. What are they teaching you at school and were is it?

 

thank y'all for the fast answers, I didn't expected that much.

bomber, it's more than a goldmine, it's perfect and more than I expected

i'm in TCE which can translate to Electronical Conception Technique, so I can make about any circuit with PIC's, analogic chips, power electronics,...

ohboy95c, actually we have seen what you told me in the last session so I'm pretty familliar with pressure sensor, temp sensor (variable resistance, voltage generator, courant generator, with their ampli-op circuit,........) My cegep is in Ste-Thérèse, province of Quebec and what they are teaching us is learning to learn, to adapt with the technology, stuff like that. for the yahoo search, yes of course i'm doing this too, but i'm glad i've asked it here since I don't think i could have found what bomber gave me in it's attechements, anyway it's better to have more infos than not enough, since this project will be important for me cause some companies and university... are going to see this

 

When you are done with the project please design a chip or something that will tell the OBD2 scanners at the emissions testing place that everything is a-ok even though I am running an AEM EMS

Not exactly legal I know, but I hate converting back to OBD2 just to run through the damn testing place...

 

that would be a doable thing, i'll try to remember this and come up with something

 

keep them coming, the more I have the better it will be

 

Could i get a email of the sensor reading chart. THis will be helpful for my ef9 .
Thanks