| Can a faulty alternator cause a tranny failure?
I own a 1994 Seville STS (Northstar) that runs great when cold.
As longer i drive it, the worse the engine idle besomes and after about 15 minutes the SES light goes on and indicates as P076 (Transmission Pressure Solenoid).
So i changed oil, the solenoid (with getting the tranny out of car).
But the failure still comes after about 15 minutes.
Today i found out, that the voltage is at 14.4 volt when engine is cold and drops slowly to about 13.5 volts.
When the voltage drops below 13.8 volt the engine gets a little bit rough and the SES light goes on.
Now my question: Is it possible that the alternator (or regulator within) has a temperature dependent failure whicht causes to produce less voltage when it heats up? And can this drop in voltage cause the pcm to throw out the P076 code?
By the way i replaced the spark plugs, ignition wires, air filter, oil filter, engine oil. So the car drives great, the tranny shifts smooth, beside the failure after about 15 minutes.
Perhaps anybody of you can help me?
I donīt want to replace the alternator only to find out, that the faulty alternator cannot cause the PCM failure.
kindest regards
Michael | 
