I got problem with error codes PCM 1350 (Ignition Control System) + 1375 (IC 24x reference circuit high voltage). It started then driving the car, suddenly the tach turned down to 0 and engine lost power and was running poor. Engine lamp turned on too. Drove the car to a shop 20 minutes away. They stated that the Ignition Module was the problem. They changed to another (used) but got same error codes, tried with a 3rd used - still same problem. The 4th worked (also used). Started up the car and after few minutes the codes was back. The shop checked all wirings, connections, grounds etc but the error codes remained. I drove the car home (with error codes) parked in the garage and turned off key. Thought to give the engine another chance and started and now the error codes was gone all times I started the car - also the tach worked and engine lamp off. But...

...Two last evenings I cleared the codes and engine was running fine in garage (as explained in my first post). Worked fine both days until I drove out from garage (cold garage), parked the car for a few minutes with engine on idle outside garage. And same thing happened as before. The car turned off by itself and then I started again the engine lamp was on, error codes back and ruff idle. Drove the car for 40 minutes or so to see what happened. Was quite poor engine run, loss of power etc all the way. Back in garage I turned off engine. Waited a few minutes. Cleared the coded and started. AND engine runs fine, no codes or engine warning lamp. Exactly as yesterday. Can someone explain this???