2000 Cadillac Deville service engine soon light flashing, runs rough, codes P1860 & P0302

Question

in July 2014 pretty much had the same issue, but the dealership said the code was "P0300. They "found" #6 cylinder miss fire, found faulty coil. they replaced bank 1 and bank 2 coils and sparks plugs. (Pretty much cost me a bundle!) Now, March 2015, pretty much same issue, but a friend used a device that gave codes P1860 & P0302. I'm going to have it towed, but who is the "right" person, or business to trust? Maybe it's not worth spending more $$, but the car is paid for and I don't want to fork out $20,000.00 for a "new" vehicle that's going to end up being another "money-trap" when that warranty ends. This is so frustrating...grrrrrr

Answer 1

P1860 TCC (torque convertor clutch) solenoid circuit

P0302 Misfire number 2 cylinder

What causes P1860 is the ECM see the TCC as a continous open circuit or short to ground circuit, One of the job for the ECM is to look for open circuit , short circuit, and  with P1860 it either a open circuit of the TCC or a grounded circuit.

 

 This sparkplug came from a vehicle that had a misfire code condition and a flashing CK ENG LT with a P0300 and a P0301.P0303 , P0304,  what happened here the sparkplug was not properly secured, it lost proper sealing of the cylinder. Sparkplugs are good indication of determining what happening within the cylinders, if the misfire is caused by a mechanical condition , such as a head gasketor cylinder valves, the cost effective route would be to get a  fuel efficient vehicle