Engine Conversions and Park/Neutral Signal

[S10Wildside]

What you should know about park/neutral when doing an engine conversion with the LS1 PCM and automatic transmission...

Camaro/Firebird
This is the only vehicle I'm aware of with the traditional single wire park/neutral indicator. Ground the orange/black wire connected to BLUE PCM connector pin 34 to indicate park/neutral. This is how the PCM knows which commanded idle value to use.

Corvette and Truck
These vehicles use four wires to the PCM to determine selected gear from a switch mounted externally on the 4L60E/4L80E. Faking the park signal by applying ground to pins 32 and 34 may result in a long delay for the PCM to recognize gear change.

Calibration Choices
Determining a base calibration begins with crank resolution type (24x or 4x), throttle type (cable or electronic), and transmission type (4L60E or 4L80E). I've seen applications where the base calibration expected the gear select switch, but the transmission was not equipped.

Park/Neutral Calibration Options
A recent customer ran into this issue and was able to change the value for gear select switch to P/N only. Currently I don't think EFILive has this, but I'm sure a .CAX could be worked up by someone with the know-how.

A practical example would be an electronic throttle equipped engine with TH350/TH400 transmission.

Hope this helps.

[schwoch1]

A practical example would be an electronic throttle equipped engine with 700R4 transmission.


How would one pull the TV cable on a 700-R4 with electronic throttle. Reason I ask, I just had someone ask the same thing and was thinking maybe you came up with a workaround and didn't tell anyone :)

Mike

[S10Wildside]

How would one pull the TV cable on a 700-R4 with electronic throttle. Reason I ask, I just had someone ask the same thing and was thinking maybe you came up with a workaround and didn't tell anyone :)

Mike
Hey Mike. Yeah, just run a pull cord into the passenger compartment. Your right hand isn't doing anything anyway, so you may as well use it for something.

The 700R4 was a bad example, I should have said TH350. Corrections above. Good call.

[Taz]

On 1999 to 2002 truck DBC applications - have seen conversions where people have mounted the TV cable from a 700R4 in the place (bracket & TB) normally occupied the Cruise Control cable. Have never done this - not sure if the geometry of the eccentric on the TB is reasonably close to provide the correct TV input to the 700R4.


Regards,
Taz

[madmax4499]

so are you saying if i have a 0411 in a muscle car with a t-400 to ground the p/n wire permanently? or leave it open. mine is grounded right now,

[Taz]

If you are using a Camaro / Firebird OS - then ground C1 pin 34 when in park / neutral - release (open) the ground when in gear.

You may be able to rig something up to any existing column shifter, or use a micro switch with an aftermarket floor shifter.


Regards,
Taz

[madmax4499]

is there a work around in the tune? there is really no easy way with the b&m quicksilver shifter.

[S10Wildside]

You cannot work around a signal (in the tune) for the transmission being physically in park VS in gear. Did I misunderstand what you are asking? This reply seems to be obvious?

[madmax4499]

i guess what im saying is mine is grounded all the time, "i have not driven the car or even put it in gear" im just working up a start up tune and looking for advise before i try to drive it.

it was running fairly good, but now it will start and then die, "like it is running out of fuel" i should just start a new thread.

[Taz]

B&M shifters are setup to use B&M micro switches. Some shifters come with a micro switch for park / neutral and another for reverse lights.

Easy to do ...


Regards,
Taz

[madmax4499]

i have the switches, i will look how it's wired, i didnt want to disable the neutral safety switch.

thank you.

[minytrker]

I normally just tune an engine swap with th350/400 or glide with a manual file. I still wire in a neutral safety switch but thats about it. Even my 99 camaro race car with a glide is setup like this and never have a issue in park or in gear.

[madmax4499]

thanks for the reply, i think that is what i will do.

[msnelgrove88]

I've got a Lq9 with a 4l60e behind it, running with a stock harness modified to stand alone. Now I need to run a crank learn and it wont read park position. I wired in a P/N switch, and tried grounding 32 and 32. still no park.... Any Ideas? Also drive by wire should hit rev limiter at 4k in park Correct?

[schwoch1]

I've got a Lq9 with a 4l60e behind it, running with a stock harness modified to stand alone. Now I need to run a crank learn and it wont read park position. I wired in a P/N switch, and tried grounding 32 and 32. still no park.... Any Ideas? Also drive by wire should hit rev limiter at 4k in park Correct?
I am going to go out on a limb and assume that you are dealing with a '04-'05-ish LQ9? I have attached the logic/truth chart for the park neutral switch and the wiring diagram for the park neutral switch. My advice to you would to be wire in the correct park neutral switch (there were 2 designs, early and late, I think you can interchange them, just have to wire the appropiate pigtail to it!!) to your 4L60E and then reattempt to do the crank learn procedure. Any time I had issues with crank relearn, it usually always boiled down to the PCM not thinking it was in park. Hope this helps!!
Mike
1261612617

[S10Wildside]

I've got a Lq9 with a 4l60e behind it, running with a stock harness modified to stand alone. Now I need to run a crank learn and it wont read park position. I wired in a P/N switch, and tried grounding 32 and 32. still no park.... Any Ideas? Also drive by wire should hit rev limiter at 4k in park Correct?

You are using a PCM calibration from a vehicle with a PRNDL switch on the side of the transmission.
You have wired in a P/N switch (which will supply a ground to the PCM when in park/neutral, otherwise open).

Now you need to change the gear select type to P/N Only. This is not available in EFILive. It can be done with TunerCat OBDII or HP Tuners.

However, without the gear select type change, you should be able to ground BLUE 32 and BLUE 34 to accomplish the park signal for the sake of crank learn. The problem with faking out the PRNDL switch (as just mentioned) is that for some reason the transition time to indicate park and in-gear is several seconds. I could see this as a potential for idle issues when transitioning from park to in-gear.

If crank learn still doesn't work...make sure no other DTCs are set. I've experienced crank learn frustrations because a fan DTC was set (the fan signal wire was not connected to a relay).

[msnelgrove88]

Sorry I didnt put the year in there, mine is an 02. And I also put a P/N when I meant I have a PRNDL switch. Sorry for the confusion. And I have tried just grounding 32 and 34 and still no park. Im starting to wonder if the problem is in the tune. Does that logic table still apply to the 02? Im thinking of going to a dealer and seeing if a Tech2 can command park and run the Crank learn. And as far as DTC's the crank learn code is the only one there. Sorry for all the questions, I just gotta figure this out! Thank y'all so much for the help!

[schwoch1]

If you post a copy of your cal I should be able to change the PRNDL to just a P/N switch with tunercat. I forgot about that!!!
The logic table also applies for the '02, as all truck based calibrations used the PRNDL switch and the F body cals used the P/N switch!!
If all else fails, you can fake out the PRNDL switch signals with a few jumper wires and some battery voltage to the correct pins on the PCM!! ALthough, it is much safer to fix it the correct way.
Get me a copy of the cal and I will see what I can do
Mike

[msnelgrove88]

I didn't do the tune nor do I have a way to post it. The logic chart is very helpful and my prnd switch is sending the correct signal to the pcm for park. But shouldn't there be a 4k rev limiter in park for a dbw system? I'm beginning to suspect this is in the tune. All of the help is greatly appreciated!

[schwoch1]

I didn't do the tune nor do I have a way to post it. The logic chart is very helpful and my prnd switch is sending the correct signal to the pcm for park. But shouldn't there be a 4k rev limiter in park for a dbw system? I'm beginning to suspect this is in the tune. All of the help is greatly appreciated!

I pulled a 2003 LQ9 tune off tunefiledepot and took a look at the ETC controlled rev limit in neutral. It is set at 5900 RPM so your cal is probably spot on. You can set it to anything you want with a tuning program of your choice, but from the factory it is set pretty high on this one!!! I will say though, sometimes the crank relearns do not take the first couple of times you try to do it. I had one just recently that I thought I was going to blow the damn motor up trying to do a crank relearn and then it took once and everything was fine!!!
Hope this helps!

Mike

[Taz]

You also require brake input to the PCM (along with the Park signal) to get the Case learn to execute. The brake pedal needs to be depressed throughout the Case learn procedure. A switch can be wired if need be.


Regards,
Taz

[schwoch1]

You also require brake input to the PCM (along with the Park signal) to get the Case learn to execute. The brake pedal needs to be depressed throughout the Case learn procedure. A switch can be wired if need be.


Regards,
Taz

Forgot about that one, thanks for reminding me of it!!!

Mike

[FirstGenThree]

I know this is a bit late and if its considered off-topic feel free to move or delete. But I thought I would share so no one shies away from something very doable.

I have a DBW '03 5.3L (L59) mated to a 200-4r. I ran the TV cable to the firewall and made an arm extending beyond the pivot point of the pedal assembly. I thought it was great until I got it wired up and realized that by 50% of available pedal movement the engine was seeing 100% throttle. I made a physical stop for the pedal at or slightly past this point. Which then meant I needed excessive 'preload' on the TV cable to still acheive full pull at full throttle. I then removed the pedal assembly and built a linkage to achieve increased pull with my new short pedal stroke. It works quite well now, the 2-3 shift is slightly high but I don't have my desired tire size on the truck yet so I will wait until that is achieved before I play with the trans governor weights.
I will be reviewing this thread so I can perform a case learn soon, I am using the previously mentioned B&M Quicksilver. Currently I have no gear transition idle issues.

[joecar]

Thanks for sharing... so now you're able to get full TV sweep from full pedal sweep (without preload/slack)...?

[FirstGenThree]

That is correct.