I have a full size Dodge 3/4 ton custom van with the 318 cid FI engine.
Came in from a trip last night and tried to start her up, and found the battery too flat, so I boosted it for a few minutes and she started right up...
BUT, the idle was extremely high. I drove it for perhaps 25 miles, let it warm up well, but the idle never dropped.
I disconnected the battery , charged it battery overnight, and started her up this morning, and the idle was now normal.
Have never seen this before. Is this a normal reaction by the drivetrain module to try to keep the revs up upon sensing a low voltage condition? (Cured by the computer deactivation and recharge) Or just a phantom symptom?