ECC climate control temp sensor measurements made easier

Post by **jreed** » 28 Oct 2014, 19:34

Thanks for asking. It's been a couple of years and I couldn't remember, so I went down and measured the resistor with an ohmmeter. I got 5.4kOhms. That value seems to work fine with the blue LED I'm using. A lower resistance will likely also work without burning out the LED-- try 500 Ohms and see. Good luck!

jlaakkonen · Post by **jlaakkonen** » 01 Oct 2015, 16:22

I'm having trouble clearing the codes from my 1996 850. After I've read all the codes by clicking the button it never comes back to the first one, but just keeps blinking loooong single blinks 1(long)-1(long)-1(long)-etc ... i counted out at least ten, and then i just turned the ignition off. Therefore even though I've tried to erase the codes, it doesn't let me do it. Also an interesting thing was that it read out the first three codes one after the other without me clicking the button and then the fan turned back on, after which I clicked the button for 1 sec and then got the fourth code. Does anyone know what these long blinks at the end mean?

Post by **jreed** » 02 Oct 2015, 04:44

I think that the repeating "1-1-1" means that you have successfully cleared the codes.

jlaakkonen · Post by **jlaakkonen** » 02 Oct 2015, 10:49

but it starts doing that before I even get a chance to clear the codes. I tested it again today, and today I had the patience to watch it blink 52 times

never stopped. I understood from all the instructions that at some point when going from one code to the next (by clicking the button) it gets back to the first code. But it doesn't let me do that :/ once the 1(long)-1(long)-1(long) blinking starts it doesn't let me do anything. I'll try googling some more but if anyone has an idea what it could mean, please share

Thanks!

Post by **jreed** » 03 Oct 2015, 05:51

For reference, I've attached a list of all the codes the ECC unit can throw. If you turn on the ignition and try to read the codes from the ECC now, what codes is it giving you before it gives "1-1-1"?

: ECC Codes list

jlaakkonen · Post by **jlaakkonen** » 08 Oct 2015, 05:28

I got these codes before it starts blinking endlessly.

1-3-5
1-4-3
2-1-1
2-3-3
3-2-5
4-1-4

But I would like to first clear these codes before I start fixing anything in case some of them don't come back after clearing.

Thanks.

Post by **jreed** » 08 Oct 2015, 05:37

Got it. Thanks. I don't understand why your ECC unit is not repeating the error codes as expected but instead is switching over to repeating 1-1-1. It's possible that your ECC unit itself is malfunctioning. If this were my unit I would remove it from the car, open it up and look inside to see if there are signs of damage on the main circuit board. Have you already tried doing this?

A couple of related posts on this topic:
https://www.matthewsvolvosite.com/forums ... =1&t=58028
https://www.matthewsvolvosite.com/forums ... =1&t=33785

jlaakkonen · Post by **jlaakkonen** » 08 Oct 2015, 17:11

That is my fear now..that the unit itself is broken...I did open it up earlier on but at that point I didn't think there was a problem with the actual unit, so I didn't check the circuit boards closely. Maybe I'll open it up again and check if there is clear damage to some components. Thanks again!

jlaakkonen · Post by **jlaakkonen** » 12 Oct 2015, 07:39

Now I opened up the unit again and the circuit boards look really healthy. I didn't see any evidence that something would have burned or exploded. Really frustrating :/. I guess there is a chance that the soldering is faulty at some spot but at least no clear cracks anywhere.

Post by **jreed** » 13 Oct 2015, 04:51

I guess at this point there is nothing to lose by reinstalling the ECC and trying to see if the problem with non-resettable codes comes back.
Also, can you share/show more about the circuit you're using to read the codes? Thanks.

ECC climate control temp sensor measurements made easier

Re: ECC climate control temp sensor measurements made easier