The development of the automatic transmission is one of the most important milestones in the history of automobiles. The automatic transmission allowed for a much wider user base than had ever been dreamed of before.
The powertrain control module (PCM), which controls virtually every function of the engine and automatic transmission, depends upon an input signal from the TPS (among other things) to calculate fuel delivery and ignition timing strategy.
Sometimes even the simplest items will cause a drivability problem. Then is this situation where the issue is both intermittent and includes a very short window in the production run. The combination of these factors can cause frustration for the technician, but thankfully this tip will help to reduce the frustration level.
Engines have become very reliable in recent years, many reaching over 200,000 miles without major issues. As technicians, we replace a lot more ignition coils than timing chains.