DTC code 17970 Quantity Adjuster upper limit reach

I have posted on this subject in the past few weeks and recieved some good advice from members. I have been unable to reply back due to being on vacation. Here is where I stand when the 17970 code was determined to be the upper limit reached on the quantity adjuster. I assumed that the computer is telling the QA to give more fuel and it has reached its limit. Checked with the service manual and it tells you check the resistance at the IP pins 5-6. It should be .5-2.5 ohms. I saw 2.0 ohms. QA is good. At that point I checked the actual Injection Quantity and it was reading 2.0-2.2. I understand that the range is 2.2-9.0. The smaller the # the richer the mixture. I went to IQ adaptation and changed the Injection Quantity to around 4.0 thinking that the mixture was on the rich side which was triggering the DTC. I went back to clear the code without success. In the manual the progression for checking the QA ends up at the ECM. Are ther any othere sensors that can trigger the ECM to tell the QA to give more fuel. Also can the ECM be removed and exchanged with another one (for troubleshooting purposes) without having to reprogram anything? ( plug and play ).

99 A4 Jetta Egr mod 2001 A4 Jetta Egr mod.
I would be glad to read the responses. Thanks

Did not mean ot post on this forum. Ment to post in TDI discussion areas. how can I transfer it to there?

If you've got VAG-COM on a laptop, connect it up and go for a drive. Bring up engine controller measuring blocks group 001 and log it. Drive the car, fully warmed, at various speeds and conditions (idle, full throttle, cruising, etc.). Then come back and post the log.