I have a 97 discovery se7. in park or neutral it idles between 2500 and 3000. the intake air temp is reading -40 but it drives down the road good. no vacuum leaks and the tps seems to be reading good.

any thoughts?

 

Sadly I'm sure anyone is just going to say to search it because it's already been discussed but I am in the same boat and I have searched it... lol

I replaced my tps and iac. From my understanding the ECMU needs to be reflashed because its in limp mode. Or find an ECMU and Alarm ECU and swap em out.

 

No, I'd think if you show -40F for IAT, and either sensor is open or the wires to it (it is the one with two conductors and a square top) are open. Break out the ohm meter. Don't think you need to reflash anything, and the alarm module does not link to the IAT. I've unplugged the IAT on my 97 and never had to reset the ECU, reflash, etc.

 

The ECU only has to be reflashed if the high idle has lasted for an extended period of time. But if you can fix the IAT or TPS before the ECU goes into limp mode then you should be fine. And the Alarm ECU is only if you swap out Engine Control Management Unit (ECMU) because the two have to be paired together.