engine heater sets "engine hot" MIL ?
weird issue somehow. Customer had a Webasto engine/interior pre-heater installed which has absolutely no connection to PCM and runs on gasoline.
when engine is cold, he remotely starts heater to have it warm and comfy when he drives off, all OK at first, about 5 minutes later display shows "engine overtemp", MIL comes off and it is hard to start thereafter and coolant temp gauge is forced to 0. He needs to pull PCM fuse to get rid of it. If he does the same when engine is hot not problems at all.
Spoke to a GM Tech today and he said he has seen that a few times on 2008 and up Silverados. Apparently, there is a engine off timer and first time when ignition comes on PCM (or BCM?) compares IAT with coolant sensors and compares it to a temperature table. If mismatch like coolant preheated to 50'S and IAT sees 10's, it "thinks" coolant temp sensor os failed and switches MIL on. BS or fact?
it sort of spoils the idea of having a pre-heater......
what are trucks doing who have the block pre-heater option? are the running a different OS? Anything I can do with HPTuners, GM is at a mess here at the moment due to the bankrupcy thing, means zero support in Europe
anbody have a solution for that as it is winter and chilly.........