What code was that?

For this weeks topic lets discuss diagnostic trouble codes and why you should pay attention to the code before performing your diagnostic approach. This past week I was at a shop assisting with a diagnoses, the code in question was a P2138 Throttle/Pedal Position Circuit Correlation. The shop had replaced the PCM and throttle body in attempts to repair this code. If you just read the code and the items they replaced you might see where I am getting at. The issue was with the APS 1 and APS 2(accelerator position sensor) and not the TPS 1 and TPS 2(throttle position sensor). I know we have all been there, we just read a code and our mind takes us straight to something. That is why it is a good practice to pull codes and at least briefly read over the service info for them before going forward. Over the years I have seen (and done) this time and time again. When I was a young Marine just learning my MOS, I was constantly trying to rush through things(and messing stuff up along the way) but in my mind I thought if I hurry then they will think highly of me. But I had an NCO sit me down and explain this to me, “always remember slow is smooth and smooth is fast”. And that is what I want you to take away from this, yes I know the flat rate system makes it to where you need to move, move ,move but if you make a major mistake (like diagnosing the wrong system instead of what is actually at fault) then you’re actually going to be spending more time than what you would have spent if you just read a little service info. So when you’re performing a diagnostic, slow down read and understand what code you’re diagnosing before diving head first in. This will save you time, and the customer money.