Jump to content

Making a temperature gauge


elbekko

Recommended Posts

Since I don't trust the temperature sender at the thermostat in the slightest, nor do I trust the gauge in the dash, I was thinking of using the EGR temperature sender on top of the cylinder head to get some sort of accurate reading. Because for all I know, with its tendency to overheat lately the cylinder head may be banana-shaped by the time the gauge rises...

Now, it seems to be pretty hard to find any actual data on what resistance values this sensor (ERC2081) has at what temperatures. I did find this interesting post, but that topic confuses me a bit (it may be because of the rather late hour :lol: ) and I'm not sure that's actually related to that sensor.

I was thinking of using a PIC or something that drives a little display I have laying about (might as well use it, right?). I'm sure I can get a friend of mine that's studying to be an electrical engineer to figure out the circuit needed to be able to actually read the resistance of the sensor (from what I've found, it goes a bit over my head sadly).

Link to comment
Share on other sites

There are a few issues round this:

- Most automotive sensors aren't very accurate anyway, the 2-wire types used for ECU's are better but still mostly ballpark. The EGR one is unlikely to be very good.

- Just buying a VDO gauge & sender is about as accurate as it's worth getting.

- You don't need a PIC, or an arduino. An LM3914 would probably do it, or if you want a digital display then buy an LCD panel meter from eBay china and use the appropriate series resistor.

- If you want better accuracy, the LM35 is a useful device although you'll get interference in a car, might be better in a TDi but on the V8 there's a lot of noise from the ignition system.

Link to comment
Share on other sites

As I said, because I already have all the bits to do this and I'm a difficult person :lol:

Managed to find the right datasheet, had to get the part number from the picture on Turner's site, as the sensor I have doesn't seem to have any writing on it :unsure:

It appears to be the Bosch 0 280 130 036. Strangely listed as an air temperature sensor, but I guess I shouldn't be surprised.

Will be picking up the PIC with analog input and my programmer at a friend's place tomorrow, and made a basic circuit in Tina to test the principle - seems to be fine :D

post-18506-0-79139700-1296417151_thumb.jpg

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy