Is the ventilation fan running? (I mean the fan that draws cabin air in and blows it into the RCM/ECM box under the hood next to the battery.) That is the only cooling provided for the module box.

My guess is CPS. They are $39.11 from AutoHaus - higher elsewhere. They are known to be temperature sensitive when they age. I'd replace it. NOW.

(Seems like a bad CPS usually throws a code, but I've read posts by members who fixed their cars iwth a CPS that was not showing a code... just thought I'd edit and throw that in.)

Click here and get ya one!