P0326 hard code.

[rguzz]

This code has been intermittent for a long time now will not reset. I detect no difference in how it runs. A few years back the knock sensors were replaced. The boost needle sits in the middle of the white indicator. PCV tests out ok with the genuine Volvo tool measured by in line vacuum testing. Is it worth swapping out ECM's at this point? I'd rather not remove the intake and inspect the wiring, etc. unless I'm more convinced that's the problem. I think I did a hard reset once by un-plugging the battery which worked for a while. ECM swap or no?, bearing in mind "it's almost never the ECM". Thanks.

[scot850]

I'm sorry that it has been a long, long time since I had this problem on an 850. I seem to recall there were 3 items on the same circuit which made determining the cause of the code difficult to identify.

The 3 things were the knock controller, the altitude sensor and there was one more but for the life of me I can't recall. The issue was all 3 things can cause this code.

In my case it was not the knock sensor, but you also have to make sure it is well grounded and the ground is clean. It was the altitude sensor which adjusts the fueling based on height above sea level if I recall. It is situated on the RH inner fender near the hood latch.

https://www.pelicanparts.com/More_Info/ ... tent=Bosch

I only wish I could remember what the 3rd item was. Something to do with the A/C?

Neil.