Put in a new battery and the fuel center and heater control center are all blank except for a "d". Also, while the "d" is displayed the heater fan stays on even after the car is shut off. The car runs great but will not pass DEQ, and my readings are higher while this "d" is being displayed. Also, the check engine light, service engine light, and coolant temp light are all on. Sometimes the system comes back and all of these lights dissapear and the heater fan turns off. Please help:hmm:


Only error code I can grab is a E52, and that is a ECM reset. The new battery would make this code appear. I am thinking PCM but I really need some feedback.

Thanks
Todd

It sounds like a poor ground at the battery maybe? Check the cables around the battery carefully for any that were shifted while changing the battery. Sometomes corrosion can build up inside the battery terminals where you cant see it. I would try replacing the battery cable terminals before anything else, especially since this showed up right after changing the battery.

Put in a new battery and the fuel center and heater control center are all blank except for a "d". Also, while the "d" is displayed the heater fan stays on even after the car is shut off. The car runs great but will not pass DEQ, and my readings are higher while this "d" is being displayed. Also, the check engine light, service engine light, and coolant temp light are all on. Sometimes the system comes back and all of these lights dissapear and the heater fan turns off. Please help:hmm:


Only error code I can grab is a E52, and that is a ECM reset. The new battery would make this code appear. I am thinking PCM but I really need some feedback.

Thanks
Todd
Mine acted bigtime screwed up when I shorted the battery post on the transmission line. I would open the door and the oil, airbag and traction active light would come on without the key even in it. I unhooked the battery and pulled on the cables a bit, jostling them around and left it unhooked about 15 minutes. I reconnected the battery and its been working ever since.

Blaze

Well, it is still doing it and it is kinda pissing me off. I have checked evrything, but I cannot find it. All gauges work once in ablue moon, and when they don't the heater fan stays on. I am my wits end.:banghead:

Replace the BCM. It is behind the glove box and has purple connectors. Find one at a salvage yard, but it must be a 90 Deville you get it from. 91 wont work as well as a 89 wont work. Sevilles and eldos will not work either. Unfortunately 90 is the year a couple changes were made and 91 is the year that a whole bunch were made. That computer drives all the stuff you are having problems with. You might want to also check the connections. Remove the glove box by unsrewing the phillips screws at the top and bottom of the box and the one above the trunk button. Pull it out and the BCM is right there sitting sideways with purple connectors.

Blaze