Cadillac fuel pump question

[baz67]

I have a question about how the fuel pump is energized and located in a Cadillac sedan. I am not sure what kind of Cadillac it was other than it was a four door sedan. Also, I would guess this one was around a 2008 or so. I am not sure because this care was involved in an accident and rolled around a hundred yards. I am a firefighter and responded to this accident. When this thing stopped rolling it caught fire. We put it out, it flared back up again, we put it out, it flared back up again... The fire was localized to the engine compartment so I was able to reach in the drivers door and turn off the ignition and pull out the keys. This whole put the fire out and flare up cycle kept going until I can only guess it ran out of fuel. We got the hood open and distinctly heard the fuel pump from under the hood on the passenger side. It did not turn off until the battery cable was cut. What would cause the fuel pump to remain energized even with the ignition off? I would also think this new of a car would have the fuel pump in the tank and not under the hood.

On a side note, this thing rolled from freeway speeds around a hundred yards and both people were able to get out before we got there on their own power. Pretty impressive because the only way I know it was a Cadillac was the emblem on the grill. That emblem did make a great target for busting out the grill though.

[CarlC]

In short, the fuel pump energizing circuit is controlled via the ECM.

The ECM, upon initial key-on, turns on the fuel pump energizing circuit by triggering a relay or control module. The signal from the ECM is BAT+, unlike almost all the others from the ECM that are BAT-. This initial turn on primes the system and turns off after a second or two if engine rotation is not sensed.

Once engine rotation is sensed the ECM continues to send a BAT+ signal to the fuel pump energizing circuit until engine rotation ceases. The ECM should kill the fuel pump energizing circuit in case of an accident and the engine dies.

I believe the 2008 CTS-V is the traditional fuel pump design that uses a relay to turn the pump on/off. They are usually very reliable, but anything can happen. If the just the right set of circumstances occurred the relay could be physically damaged, the fuse block to short, etc. in such as way to cause power to be sent to the pump during an accident.