Tricking my ecm????

[gn_steve]

Hi guys and girls heres my question i whant to add fuel at wot on my comander chip they say ignition on put shifter to drive and ac on abd i can adjust my wot fuel heres the question i have a th-350 trans in the car how do i trick the ecm in thinking its in drive???
Cause theres no wiring harness going to the trans so how does it know its in drive???

 

[earlbrown]

I knows it's in drive from the PRN switch on the steering column. You should be fine. The trans data you know longer have is when you're in 3rd or 4th(lol) gear.

 

[gn_steve]

But i dont even think that the steering colum turns when i shift so i would have to do manualy !

 

[Raeban]

But i dont even think that the steering colum turns when i shift so i would have to do manualy !

Huh? What earl was referring to is that the ECM will "see" that you are in drive from the switch on the steering column. That switch is connected to the mechanical linkage on the drivers side of the trans. As far as adding fuel to your chip you should be able to see that you are adjusting the correct parameter on your scanmaster on the INT setting. Then switch to the BLM setting on your scanmaster to see what value you are setting it to.

 

[TurboDave]

He probably doesn't have linkage any longer. That's usually the first casualty of a tranny type swap.

Sent from my QMV7A tablet via Tapatalk.

 

[gn_steve]

He probably doesn't have linkage any longer. That's usually the first casualty of a tranny type swap.

Sent from my QMV7A tablet via Tapatalk.

What he says

 

[earlbrown]

If the steering wheel doesn't lock, the linkage is gone (along with reverse lights).


Sounds like you need to either mark the column so you can find it for 'drive' or slice in a button/switch to 'put it in drive' for tuning.

 

[RmvBfrFlght]

The P/N safety interlock is also gone... Can start the engine with the transmission in a drive position.

RemoveBeforeFlight

 

[earlbrown]

That would be a neat anti-theft gimmick too. Just swing the column into Low gear.

 

[Raeban]

Well the fix for getting to the chip parameters would be to wire in a switch to supply the ground required for the ECM. It is personal preference about having a car without the start protection but with some creativity you could come up with a shifter mounted one.

 

[earlbrown]

Orn/Blk is only or park and neutral. That pictograph doesn't shot the output wire for Drive.

 

[Raeban]

I wasn't aware there was a drive circuit to the ECM. As you mentioned before there is a third and fourth gear from the trans. Enlighten me Earl!

 

[earlbrown]

Beats me. I have a 200 in my car. I've never had to deal with this crap. Plus I enjoy the overdrive and lockup ( I did get my ass kicked while both my 3rd and 4th gear switches WHICH ARE N.O. failed after my car was stolen from sitting).

I was surprised to hear there's a signal wire that indicated Drive when the OP posted the problem. I was just thinking it was Park and Neutral that ran to he ECM and Reverse that ran to the lights. It might be an algorithm of some sort where ground has to vanish, blink, then vanish again to indicate drive. I'm not a chip burner so that's just a guess.


I'm on he way to drink beers with a hot 22yo before she loses her looks so the schematics search will have to wait.

 

[Raeban]

Actually after looking at that pictograph above I don't think it needs a drive circuit. THe little resistor would mean that when the switch is open it sees a high volt signal and when the switch closes in P and N it goes low

 

[Raeban]

Beats me. I have a 200 in my car. I've never had to deal with this crap. Plus I enjoy the overdrive and lockup ( I did get my ass kicked while both my 3rd and 4th gear switches WHICH ARE N.O. failed after my car was stolen from sitting).

I was surprised to hear there's a signal wire that indicated Drive when the OP posted the problem. I was just thinking it was Park and Neutral that ran to he ECM and Reverse that ran to the lights. It might be an algorithm of some sort where ground has to vanish, blink, then vanish again to indicate drive. I'm not a chip burner so that's just a guess.


I'm on he way to drink beers with a hot 22yo before she loses her looks so the schematics search will have to wait.

I was about to suggest opening another beer...

 

[1952ray]

I was about to suggest opening another beer...

Earl screw the beer , the hot 22yo sounds better

 

[earlbrown]

I've already started on the beers. Ive been working on the vac brake conversion on my car and for some reason the badass CRC brake parts cleaner makes paint fisheye. Needless to say the booster isn't black at the moment. lol


Time for some hot chick therapy

 

[GNONYX]

Fill the tub with beer and go skinny dripping

 

[RmvBfrFlght]

Actually after looking at that pictograph above I don't think it needs a drive circuit. THe little resistor would mean that when the switch is open it sees a high volt signal and when the switch closes in P and N it goes low

Another entertaining thread , beer, hot 22 YO's and skinny dipping, what else can we ask for.

Oh, umm, yes, with the P/N line to the ECM open the ECM sees that as 'in drive'. Ground the wire and the ECM sees it as P/N. The ECM uses the signal for idle speed control (different between P/N and drive), and the DFCO uses it to exit if the shifter is moved to the neutral position. This is to prevent the engine from stalling.

It may also be used elsewhere.

RemoveBeforeFlight

 

[Raeban]

Another entertaining thread , beer, hot 22 YO's and skinny dipping, what else can we ask for.

Oh, umm, yes, with the P/N line to the ECM open the ECM sees that as 'in drive'. Ground the wire and the ECM sees it as P/N. The ECM uses the signal for idle speed control (different between P/N and drive), and the DFCO uses it to exit if the shifter is moved to the neutral position. This is to prevent the engine from stalling.

It may also be used elsewhere.

RemoveBeforeFlight

Hmm nice tidbit about the DFCO thanks!