P1478

98 Plymouth Voyager 3.3. Got a P1478 code. Battery Temp Sensor Volts Out of Limit
What does this mean and how do I fix it?

Dave

P1478 (M) Battery Temperature Sensor Volts Out Internal temperature sensor input voltage out of an of Limit, acceptable range.

I spent an hour looking and nothing about how to or what exactly it is. So sorry. Will try tomorrow.

Thanks. The van runs fine and the only issue I see is that my temp gauge reads too low or not consistant

I wonder if the coolant temp sensor is wonky giving me the the wierd action the guage and making wierd electical issues arise.

98 Plymouth Voyager 3.3. Got a P1478 code. Battery Temp Sensor Volts Out of Limit
What does this mean and how do I fix it?

Dave
In my 2000 prints that sensor is internal to the PCM (Powertrain Control Module(computer)). It is used to increase or decrease the charge rate depending on the local temperature. Hot weather decrease, cold increase. It is a code that should turn on the Check Engine Light. Not sure what it does in this case to the system voltage. I would clear up any clearly flakey temp sensors though first, such as the coolant sensor. At least that is with in reach.

Ok now things are really getting wierd. I still have the 1478 code and my temp guage is still wonky. I couldn't test any sensors today as its been pouring rain all day here. But now when I turn off the ignition the engine keeps running. I had to take the relay for the auto shutdown out to get it to stop...but still had to disconnect th battery so the acceseries would shut down. I am beginning to think the van is haunted. I really cant complain too much. I have nearly 600 000 kms on the origional engine and tranny.

98 Plymouth Voyager 3.3. Got a P1478 code. Battery Temp Sensor Volts Out of Limit
What does this mean and how do I fix it?

Dave
isn't this the sensor in the battery tray that monitors battery temperature? and depending on the battery temp the sensor adjusts the voltage regulator in the pcm thus raising or lowering the charging rate of the alt and the battery! just a thought i havn't looked at my 2001 caravan but other chrysler products i have owned, have a battery temp sensor! mike

Ok now things are really getting wierd. I still have the 1478 code and my temp guage is still wonky. I couldn't test any sensors today as its been pouring rain all day here. But now when I turn off the ignition the engine keeps running. I had to take the relay for the auto shutdown out to get it to stop...but still had to disconnect th battery so the acceseries would shut down. I am beginning to think the van is haunted. I really cant complain too much. I have nearly 600 000 kms on the origional engine and tranny.

Well, I've done it now. Had the van out today, still have the P1478 code. But now it runs a bit rough. Till finally it stalls and I have smoke coming from under the hood. I quickly disconnect the battery. Smoke was coming from under the PCM. I hooked the battery back up once the smoke stopped and I still have all accesaries. But wont even turn over. I unhooked the battery to be safe .Can I assume that I have fried the PCM? Got it towed home but have no time to do anything with Christmas tomorrow. Maybe Boxing day I can see what damage I have done. Should I start looking for a new PCM?
Happy Holidays and thanks for any help you can offer