I had a Hawkeye and have a Nanocom.
Both will reset all values.

 

Any OBD2 equipped vehicles ECU will reset anytime the battery is disconnected or dies. High dollar scanners can actually see what all the sensors "readiness" status is. Vehicles fail emissions testing all the time here at my shop for that. Most people don't even know what it is. The ONLY way to have those sensors go back to a ready status (re-learn so to speak) is to drive the vehicle aka a "drive cycle". It can be all kinds of weird stuff like driving a certain mph or a certain distance for a set amount of time. That's what Rover is referring to.

That's why I hate these so called "professional" mechanics that replace something on someones car, clear the code, and then give it back to them saying it's fixed only to have the CEL (Check Engine Light or Service Engine Soon light) come on after the sensors come back to a ready status. The CEL will go off on its own either after it's started or after the drive cycle is completed if the issue has been correctly fixed. VERY rarely will it need to be manually reset. I've had idiots that claim they have been a mechanic for decades not even know what that is and wanna call and cuss me out because they don't understand basic stuff that any certified mechanic should know.

 

OK, that's the key takeaway here for me. All flash memory is volatile and will not be stored if power is removed. I know that's the case with Motronic 1.1 and 1.3 that I'm familiar with, but I wasn't sure how far we'd come in the 18 years since that generation now that these trucks are using 5.2.1. Thanks Chuck.

 

There is a different setting for the Middle East market than for the rest of the world, must get hot there or something!

 

clearing or resetting the adaptive values is easy with nanocom, but the issue really seems to be, for example, relearning the correct values using a specific workload, like 2nd gear accel -> 5200rpm ->coast to stop. I can hit 'clear adaptive memory' but testbook has all the relearning procedures.....

does the ECU relearn on its own over time? It must because I have not done any of these relearning procedures....

 

ABS, SRS, and engine faults have never left the many SLABS or ECU's I've had in storage for many many many years. 97 D1 ABS unit still had all the fault codes my D1 had when it got wrecked in 2000. I just installed it into my 95 D1 and all the faults were still there!

​​​​​​99 P38 ECU = still had tons of misfire faults after it sat for a few years as well.