Hello and Welcome! I'm Billy and i will assist you with your inquiry. Feel free to ask if any further info is needed.
Were the battery cables checked if loose, dirty etc..?
was the body control module behind the glovebox checked for water ingress, loose connector?
Yes on the battery cables, and are clean and firmly attached. Body Control Unit (BCU) has not been checked but I can check it if you still think that's the answer after the following update: Additionally, since the last post, have had the ABS light, hill descent control failure light, and the traction control light ilumminate as I am driving (all 3 at once at same time illuminated together), and stay illuminated even after I stop (indicating a fault in the system per the Manual). If I simply turn off the car and re-start, all 3 lights are off. Finally, the Service Engine Soon light has come on, but then later goes off. The reason I don't think its the BCU is that I didn't think the aboce were controlled, though the power windows and even a relay to the tarter would be. Might it still be the BCU or does the additional information give you pause?
The ABS, hill descent and traction control are controlled by a different control unit. The engine is controlled by a different control unit too. So we have faults in three control units.
It could be that you have water ingress to the BCU (or its wiring connectors), and other problems with the other control units.
However, now, the best way to proceed would be:
check the body control unit's cable connectors, make sure it is clean and tight.
- check the power output of the alternator and battery (as low or high power supply would cause fault codes in the systems)
having checked these and if the problem persists, you need to have the vehicle scanned for fault codes. AS the fault codes should point out the faulty components or circuits. Get back to me with the fault codes and we will take it from there...
Thank you for your trust! Get back to me if you need more info...Thank you in advance for the positive rating...http://www.justanswer.com/car/expert-billy/