Approximately 300 calls a day comes in on ATSG’s technical hotline with various automatic transmission problems to be resolved. The type of problems we encounter today is so dramatically different compared to the early 90’s when I started with ATSG.
To diagnose a transmission with an intermittent shift shuttle complaint by the driver (3-4-3-4-3), only to discover that the problem occurred when the driver’s cell phone rang, or that he passes by high tension power lines the same place every day on his way to work, causes one to forget the fundamentals. As a result, we are always looking for the odd ball cause to a malfunction forgetting the fundamentals. I call being misguided like this the “forge-da-mental” syndrome. You simply forget the fundamentals and you go “mental” trying to fix an elusive problem. There will be plenty of needful occasions to look for the odd ball cause but never at the expense of bypassing the fundamentals first. Many odd ball issues are resolved at the fundamental level.
We all should know by now that everything starts with the battery. Without a properly working power source, computer modules produce issues not found in any diagnostic tree. And this is what this short series of Fundamentals or Forgetamentals will be all about. Short pieces of some of the problems we have encountered that was due to power or grounds in one way or another.
It is not difficult to open the hood and do a quick visual inspection of the battery. In this case the vehicle owner changed the battery himself with an incorrect application. The vehicle (a Ford Focus) exhibited intermittent shift complaints and the engine had a stumble to it. Several P0600 codes related to the PCM was stored. Clearing the codes with the hood open, the system remained free of codes and the engine ran smooth. Of course we couldn’t road test the vehicle with the hood open. But once the correct battery was installed, the intermittent shift complaints were resolved yet a P0733 gear ratio suddenly emerged.
Intermittent electrical codes, battery voltage low codes, harsh shifts, engine flare during a shift, rough idle are just some of the issues we have encountered that were all resolved by replacing a bad battery. It doesn’t take much time to do a visual of the battery, clean connections, make an open post battery check and perform a load test. It took me longer to write this article than to perform these simple basic procedures. It may come as a surprise as to the amount of issues that can be resolved by starting your diagnostics at the battery. Making this procedure a habit, you will eliminate an important aspect of the vehicles operating system as the cause of an issue should you be dealing with a real odd-ball problem. Don’t go “mental” forgetting the fundamentals!
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