Hi everyone!

I'm loving my recently acquired 1995 Volvo 850 wagon, and I've been tackling all sorts of issues. One that's mildly annoying to me is the ECC ac recirculation blinking for 20 seconds after I turn the key to ignition position.

It does the usual, but it doesn't seem like there's anything wrong at all. Everything seems to work fine! So I went under the hood to pull the code for the AC system. The code that the test lead style ODB-1(?) diagnostics unit gives in port B-1 is

1 2 1

and I have cleared it with the 4-1-5-1 trick multiple times to no avail.

According to the haynes manual, that code is outside temp sensor shorted to ground. Of course, the same manual doesn't know where the outside temperature sensor is even located, so I am not sure I believe that manual. The outside temp sensor is not located in the middle of the engine bay as the manual states, it's located directly underneath the grille, closer to the driver's side. There is no short, and the temp sensor works fine. Mine was not sitting in the mount and was sort of swinging around, but it's fine.

I just want the blinking to stop because I'm OCD about it. Where should I start? Does anyone have a better idea about that code 1 2 1?

I truly appreciate any help or words of wisdom

 

Hello again,

The OAT sensor you found is probably for the instrument LCD reading purpose only, and the one used for the ECU input is closer to the firewall; I'll attach a pic but I'll have to delete them within the next few days so be quick to save it in your PC.

I'll also attach a code-clearing procedure. The factory manual also states that a faulty power-stage unit (resistor) could trigger 1-2-1. But the self-diagnostic on 850 is fickle, and as long as the system operates normally after the blinking stops, I wouldn't worry about it. I used to clear codes and after a week or two, the blinking came back[8D].

I hope this helps.


JPN

 

Thanks a ton, hopefully that help me out. Honestly, I still can't find the sensor! It's the same pic as in the haynes manual, which isn't very descriptive somehow. Anyway, in the end, since it doesn't seem to really cause any problem (what would an external temp sensor have to do with the AC anyway?), even if I get nowhere with the problem I won't be too terribly disappointed in myself

Thanks again, JPN.

 

Hi Deathbots,

>what would an external temp sensor have to do with the AC anyway?)

That is a good point, what does engine room temp matter? If Volvo's worried about the compressor temp getting too high, they could have put on a temp sensor on the compressor itself.

I can only assume it's Volvo Technology[8D]. They really need to restructure A/C department.


JPN