CA legal LS swap

[Camar068]

hmmm.....in a 2 door truck with a 4 door electric harness in place......might have found a use for one of those extra switches @bucket Thx again M8

 

[swilson143]

Thanks, did you use the AT manual shift shaft position sensor? Reason I asked is I bypassed mine. Not sure if it makes a difference.

Thanks for your reply.

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The guy that programed my PCM initially disabled the PRNDL switch which you have pictured above.

Turns out having that disabled prevents you from being able to do a crank relearn!! I was fighting my engine swap for a couple of months trying to figure out why I was getting false misfires popping up. The bigger issue was that the false misfires would cause the PCM to disengage the TCC. I'd be cruising along the freeway and for no apparent reason the torque converter would unlock. It was driving me crazy.

After I enabled the PRNDL switch, I was able to do a crank relearn and it fixed the problem immediately.

The tow/haul mode was functioning when the PRNDL switch was deactivated, so I think you'll be okay

 

[Bextreme04]

Good idea. They may have a self holding relay/connection in the switch that gives you an on/off display as well as a separate momentary switch all built into one. With out looking, probably 3-4 connections.

They don't. The OEM applications send a digital message to the BCM that performance mode is activated, which illuminates the tow/haul light in the cluster. There is no way to trigger the light with an analog signal from the ECM.

I got one of those buttons with the trailer on it from an express van in the junkyard for $2. It has a backlight, which I'm going to repurpose as the indicator lamp. You can get a simple latching relay to enable the light at the right times(i.e. toggles on/off with press and off when ignition off)

 

[swilson143]

@swilson143 just an idea I had after your post above. GM does make Tow/Haul switches for a few trucks in case someone wants a factory looking switch. I looked at a few of the pictures and they appear to be a 2-pin connector, but I don't know if it is a momentary type switch or on/off.

The last picture is a lighted Tow/haul button from Billet Automotive Buttons. It comes in back lit, Halo or Stainless halo. There are multiple colors and comes as a latching or momentary switch.

Those are pretty slick switches. The one I used is identical to your last photo, except not labeled

 

[Camar068]

The guy that programed my PCM initially disabled the PRNDL switch which you have pictured above.

Turns out having that disabled prevents you from being able to do a crank relearn!! I was fighting my engine swap for a couple of months trying to figure out why I was getting false misfires popping up. The bigger issue was that the false misfires would cause the PCM to disengage the TCC. I'd be cruising along the freeway and for no apparent reason the torque converter would unlock. It was driving me crazy.

After I enabled the PRNDL switch, I was able to do a crank relearn and it fixed the problem immediately.

The tow/haul mode was functioning when the PRNDL switch was deactivated, so I think you'll be okay

Thanks for the info on the crank relearn.....never heard of it. I'll dig further as I've been getting a knock sensor code since the install. Might be related.....maybe not.

Thanks again

 

[Bextreme04]

Thanks for the info on the crank relearn.....never heard of it. I'll dig further as I've been getting a knock sensor code since the install. Might be related.....maybe not.

Thanks again

Its usually known as a CASE relearn and in most cases it requires a scan tool to trigger the procedure. I have seen a few things that talk about doing it without a scan tool, but most say you MUST have a scan tool that is capable of triggering the relearn.

https://www.trailvoy.com/threads/the-actual-case-relearn-procedure.23968/

 

[swilson143]

I did the procedure using HP tuners. It was extremely vague. When you choose the process in their software, it tells you what to do ... Start the motor, increase revs over 2-3 second until the engine hits fuel cut off, then release the throttle and turn the engine off

You don't get any indication that the process has begun or that it's successfully completed.

A mechanic friend has a super wizbang snap-on scanner. He tells me his gives him an indication that the process was completed.

I know it worked though, because my false misfires disappeared!

 

[jjester6000]

Man, I'm so glad that I don't live in california.

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I don't think that any vehicle I have ever owned would have been legal there, except for maybe my '98 Suburban, but not for long (383 swap?)

You must be registered for see images attach

 

[Raider L]

@swilson143,

Did you need a lap top to do the downloads, updates, changes to the BCM, etc., and if so did you use it during the inspection? I've heard so much that these engines require a lap top to make tune ups and other program changes. I'm better off just staying with old engines because I know nothing about doing anything like you did.

I did read through most of it and it's all very understandable. I have to congratulate you on such a studious effort on your engine change and especially dealing with the inspectors. At least you knew what you were going to have to deal with and made an effort to go at it head on.

Yes, I've found that it's the luck of the draw to get a government employee who will listen as well as inform you when it comes to letting you know about the law. Most aren't that nice and don't care if you know the law or not. Even in Louisiana you don't always get a nice person because they have to deal with d**k heads all day and by the time you get him he's had enough!

 

[swilson143]

To disable VATs, turn on electric fan controllers, etc you either need a laptop and a program like HP Tuners, or you can just pay a shop to program your PCM for you.

If you're only programming one vehicle, one time, it's much cheaper to pay a shop to do the programming.

In your state I imagine you have a lot more freedom to play with the PCM programming to increase performance. For that reason you might want your own copy of HP Tuners (or a friend with one) so you can make changes repeatedly until you are happy with its performance

 

[Raider L]

@swilson143,

Are you a writer by any chance? Or are you some kind of a program directer for a corporation that has to write up complicated programs for corporate distribution? Your write up was as concice as any I have ever read.
You need to put out a pamphlet on doing what you did. I'll bet a bunch of people out there in California who would do what you did if they heard the truth from some one who has done it, twice already. Distribute the pamphlet though the auto parts stores, cruise in's, car shows. Set up a table at the next car show and have poster size photos of what you did and all the forms and what not programing and all that other stuff, and you'd get a thousand people at your table. You'd also meet other people who've done engine swaps to and you all could shop talk. You could put out a free questionnaire and if they wanted further info charge a few bucks for the pamphlet. You would make money and show people whats possible since so many think it's impossible to do what you did in California!

 

[Raider L]

@swilson143,

In Louisiana you can rip the PCM out and put in a blown Hemi in a new car and no one cares. All they would ask about is whether it's safe on the street or not. In Louisiana there are no limits or restrictions on what you want to do. They really don't care what you did.

 

[Camar068]

Just used a momentary switch.

For those looking to do this, Tow/haul needs to be turned on using HP tuners. If my memory serves me, it's actually called tranny performance mode in HP tuners.

Then you'll need to run a wire inside the cab from your PCM (pin Blue-71) to a momentary switch. The other side of the momentary switch just gets grounded.

After you've started the engine just press the momentary switch once to activate tow/haul. Press it again to deactivate it.

You'll get no visual feedback that tow/haul mode is activated. And each time you turn the ignition off Tow/haul will go back to the default, which is off.

You'll be able to feel it when you drive though. It causes the truck to hold gears till a higher RPM before shifting. Also helps it not to shift to a lower gear when you're climbing hills.

wired it up tonight. Won't know until tomorrow if it works or not. Few cold beverages

 

[Snoots]

After living? in that damned state for 10 years I learned one thing, it's easier and cheaper to photoshop a passing cert than deal with the CARB.

Or move to Nevada.

 

[swilson143]

Sadly, I'm selling the Suburban. Needed a diesel truck for all the towing I do and can't afford to have both vehicles.

https://bringatrailer.com/listing/1991-gmc-suburban-4/