ECM // ECU Reset ...... Any harm To Do it ???

If you read my other current post (crank wont start ,, help) ,
I unplugged my fuel pump control module , then went to start the truck to see if it would crank and NOT start . Well. it cranked and didnt start , just as expected,
then I plugged it back in and it wont start. Just crank no start. (if youre asking why, im considering using that area to install a kill switch and was considering using one of those wires and wanted to see what happens when it is cranked but unplugged)

I have tripple checked all my connections , the 5 tabs in the harness end , unplugged it and plugged it back in 5 times now , checked fuses etc . Maybe the key immobilizer system clicked into a safe mode or something?

I have read of people who have had the same crank no start issue doing other things like changing out a battery etc . and they mention doing a reset process of the ECM, where you jump port 4 and 13 with paperclip and let it reset for 30min etc remove the paperclip and start it , and it re learns... im wondering if this might help my situation??


At this point I am considering doing this reset process and thought id ask if it was safe to do?

2016 tundra 5.7 4x4 limited with key immobilizer system

 

bump for attention

 

I’ve never heard of having that issue from simply changing a battery. You have other issues. I would strongly advise trying to jump pins on your ecu. That’s a sure fire way to turn your truck into a 5700 lb paper weight.
Sounds like you just may need to have the security feature unlocked. Bring it to a dealership.

 

thanks for the reply. Yes Im guessing im chasing some security feature that has me locked

but please clarify,
youd strongly advise , or strongly NOT advise ,

 

Good catch. Haha. “Strongly advise NOT too jump the pins”.

 

I would get techstream on your laptop and a obd2 dongle and see what’s going on in there. Also checking for codes. Jumping the pins should just do a manual ecu relearn which can solve alot of issues.

 

Did you try a different key?

If I leave the key in mine overnight I won't start in the morning, only crank and crank.

Pull the key out and flip it over and it will start.

I didn't find out until much later that this is an actual anti theft feature.

 

thx for the replies,
I have 3 keys , I will try them all.
I Want to learn more about the pin 4 / 13 jumper thing, ive seen it mentioned other subjects including during a transmission fluid service, to varify its in proper temp to be level checked etc
If it is totally safe and harmeless, I will try it , but trying to get accurate feedback to see if it can harm the situation or open more cans of worms

 

Truck is still dead in the driveway , dont have scanner or know anyone with one , so cant check for codes.
Anyone have any feedback on doing the pin 4 & 13 ECM reboot?
can it cause any problems? is it safe to do ?

 

You can try unhooking both battery cables and touchingh the wires together. Let it sit for 20 mins and hook the battery back up. Touching the wires together (NOT the battery terminals or any wires hooked up to the battery!!) will drain any residual current left computer capacitors and reset things.

 

are you saying to disconnect the battery cables , then grab both of the cars cables (pos and neg) and just tough them together? or leave them touching for 20 min?
Anyone else done this ?
Is there any harm associated with doing this ? or is it completely safe ?

 

It safe as long as neither cable end it connected to a battery post.

I do it often before I change air bags.

 

Capacitors discharge instantly (or near enough to it), so you don’t need to touch them together for 20 minutes - a few seconds is sufficient.

 

I read that doing this will clear any current codes.
I think im gonna rent an OBD scanner and retreive any current codes before I consider do the discharge procedure.

Any advise , ideas , experience is greatly appreciated

 

You can buy a scanner at Harbor Freight. 40-60 bucks or less.

 

My problem has been fixed.
It was the pin tension on the connection at the fuel control module harness (female wire harness end) .
The center (ground wire) was too loose.
If youre curious to what im refering to , it can be seen in this video where this guy had the same problem. If you want to get to the video point, its right at 11:40

https://www.youtube.com/watch?v=miNUy43Qy48&t=918s

thanks to all who replied with advise , ideas and suggestions