T56 reverse lockout problem

[firebirdzig]

I have an LS2 and t56 in my firebird. I used the PSI harness and ecm that is wired for the reverse lockout. When I try to shift into reverse it is really hard to get in. To the point where the exhaust shop and glass shop couldn’t figure out how to get it into reverse. I have 12v going to the plug and I even tried a new lock out solenoid and that didn’t work either. Any ideas on what do next? Thanks in advance.

[Z06vet]

Have you spoken with PSI to help you diagnose? Is your speedo working accurately? Can you actuate the solenoid on the bench?

[oleyeller]

Check the pins in the connector at the solenoid. I had a similar problem, and found a bad connection to the solenoid. The pins pushed back into the connector housing when the connector was mated. It was weird, when I first started the car, I could get reverse with no problem, but once I got somewhere, I could not get reverse. I then determined if I shut the engine off and restarted it, I could easily get reverse... fixed the connector and it solved the problem.

[firebirdzig]

I will check the pins when I get the car back. PSI said it should work if I have 12v to the plug.

[GoodysGotaCuda]

You do have a good ground, right?

If i remember right, it's usually ground switched and is provided constant 12v power.

[c4racer2]

I have mine wired to the brake light switch. And you can hear the solenoid click when the brake pedal is pushed

[firebirdzig]

I should be getting the car back tomorrow and hopefully I’ll be able to get it figured out! Thanks for the pointers

[firebirdzig]

After another phone call
To PSI, they looked up my tune. They never enabled the reverse on the computer.

[icemanrd19]

It’s a press of the button on hp tuners to activate

[timopajala]

i made own switch for the reverse lock out. Its not good to hook it to the brake lights, it will open every time when you hit the brakes. Solenoid will wear out much faster with that kind of setup. I have push button in under the dash thats barely visible.

[andrewb70]

i made own switch for the reverse lock out. Its not good to hook it to the brake lights, it will open every time when you hit the brakes. Solenoid will wear out much faster with that kind of setup. I have push button in under the dash thats barely visible.

Plus, consider if you get on the brakes and want to shift from 6th to 5th...I prefer mine be activated by the ECU, as intended.

Andrew

[timopajala]

Plus, consider if you get on the brakes and want to shift from 6th to 5th...I prefer mine be activated by the ECU, as intended.

Andrew

Auts! you are absolutely right, might get some real damage after that! Activated by ecu or switch to push is the way to go!

[SSLance]

I prefer mine be activated by the ECU, as intended.

Andrew


Let me know when you figure out a way to do that with my ECU... :D

I just recently rewired my lockout from my non-functioning GRC module to the brake pedal switch and I'm LOVING not having to two hand the shifter into reverse any longer. Been like that for 4 years now...

[andrewb70]

Let me know when you figure out a way to do that with my ECU... :D

I just recently rewired my lockout from my non-functioning GRC module to the brake pedal switch and I'm LOVING not having to two hand the shifter into reverse any longer. Been like that for 4 years now...

I have it working on my Dominator. Text me tomorrow.

Andrew

[firebirdzig]

After taking the car to be tuned, PSI used an ECU from an 07 Silverado (a vehicle that did not offer a manual) and that is the reason why the reverse solenoid will not engage. Not sure what I’m going to do next.

[badazz81z28]

Buy another ECU and transfer the tune over.



After taking the car to be tuned, PSI used an ECU from an 07 Silverado (a vehicle that did not offer a manual) and that is the reason why the reverse solenoid will not engage. Not sure what I’m going to do next.

[csouth]

Buy another ECU and transfer the tune over.

I thought the tune and ECU had to match. ie the base tune had to be from a manual car that had the same model ECU e38, e40 or e67?

[badazz81z28]

I thought the tune and ECU had to match. ie the base tune had to be from a manual car that had the same model ECU e38, e40 or e67?


Honestly...I really didn't agree that your current ECU wouldn't work because it was an auto car. What type of ECU is it? E38/E67 etc?


Did you pin the socket on the harness?


I could be off base here, but an E67 is an E67....For example I have a E67 for a LS3. I have it running an LS7. Additionally, the GM harness didn't have a wire or a pin for the reverse lock-out and I added it and it works fine.

[csouth]

Honestly...I really didn't agree that your current ECU wouldn't work because it was an auto car. What type of ECU is it? E38/E67 etc?


Did you pin the socket on the harness?


I could be off base here, but an E67 is an E67....For example I have a E67 for a LS3. I have it running an LS7. Additionally, the GM harness didn't have a wire or a pin for the reverse lock-out and I added it and it works fine.

I'm not the OP, i was just asking... The LS7 and LS3 both use e67.

Based on what i see the OP should have an E38 ECU if its from a 2007 Silverado. Assuming he bought both the ECU and harness from PSI, it should be wired for reverse lockout. He could possibly have that ECU overwritten with a base tune from an LS2 Corvette with manual wich i belive had e38 also?

[XLexusTech]

OK simple fix.. pull the solenoid out.. trim the spring down and reinstall.
Blog post here.. https://www.grannasracing.com/blogs/news/gr-series-transmission-install-part-1-t56-magnum-reverse-lockout-mod

[rchaskin]

OK simple fix.. pull the solenoid out.. trim the spring down and reinstall.
Blog post here.. https://www.grannasracing.com/blogs/news/gr-series-transmission-install-part-1-t56-magnum-reverse-lockout-mod

This is what I did. I cut just a little more off mine.
Easy shift into reverse (with one hand..lol) and it stays in the 5/6 gate when shifting to 5th.

[Z06vet]

I used to swap in a soft spring that I purchased of ebay. I did this for several builds years ago. I never liked it, and one time on a WOT 4-5 shift... i hit the reverse gate. It never actually went in (grinded). It damaged the trans though. So I asked my harness builder if we could make the factory solenoid activate. He says yes of course. Been using the ecm ever since. I don't use the E67 because I just don't care for it. The E38 is my preference. I would get an E38 w an 06 or 07 LS2 manual (6 speed)corvette file in it. I know that will solve your issue. I have run into weird glitches not starting off with the file that closely matches the engine/trans. Lots of ways to make things work in these swaps. But this has worked best for me.

[badazz81z28]

I'm not the OP, i was just asking... The LS7 and LS3 both use e67.

Based on what i see the OP should have an E38 ECU if its from a 2007 Silverado. Assuming he bought both the ECU and harness from PSI, it should be wired for reverse lockout. He could possibly have that ECU overwritten with a base tune from an LS2 Corvette with manual wich i belive had e38 also?

The E67 isn’t actually a LS3/LS7 ECU. A factory ECU for these engines was mainly the the E38. Most of the new trucks, Hummers, LS9 and some LS3s saw the E67.
Based on my limited tuning knowledge, the car being and auto or manual is not part of the tune. When you move a tune from one ECU to another, your just changing running parameters.

Its important to know what ECU the OP is running. It may not be wired correctly. The signal from the computer is a ground, you would need to run a 12v power source to make it work.

[Z06vet]

auto & manual is def a part of the file. At least in the factory tunes. U can change it in HP tuners or efi live, etc, but that doesn't actually change the file like in the old 411 ecm.. For example, The LS2 MAP sens is different from LS3. If you try to run an automatic file w a manual trans, you need to wire in a TCM to get the correct speedo voltage. Otherwise the ecm reads 12 volts,and sees 158mph all the time. I bought a PSi computer for an LS2/T56 build a few years ago. I asked for an LS2 manual file from an 07 corvette. I had several issues, and upon pulling the file it was for an 08 corvette. 6 months and many hours on the phone, It never got fixed. The told me they don't have any LS2 files. He assured me they changed everything needed in the tune for an LS2. Finally I bought a blank ecm and had the LS2 file loaded on it. Every single problem was fixed. This has happened to others and in another build of mine. There are so many variables, and some have ways of getting around it. I'm just trying to help simplify. Oh, and the newer ecms don't like to be overwritten with a different file lol. Have a couple that we bricked experimenting :)

[badazz81z28]

auto & manual is def a part of the file. At least in the factory tunes. U can change it in HP tuners or efi live, etc, but that doesn't actually change the file like in the old 411 ecm.. For example, The LS2 MAP sens is different from LS3. If you try to run an automatic file w a manual trans, you need to wire in a TCM to get the correct speedo voltage. Otherwise the ecm reads 12 volts,and sees 158mph all the time. I bought a PSi computer for an LS2/T56 build a few years ago. I asked for an LS2 manual file from an 07 corvette. I had several issues, and upon pulling the file it was for an 08 corvette. 6 months and many hours on the phone, It never got fixed. The told me they don't have any LS2 files. He assured me they changed everything needed in the tune for an LS2. Finally I bought a blank ecm and had the LS2 file loaded on it. Every single problem was fixed. This has happened to others and in another build of mine. There are so many variables, and some have ways of getting around it. I'm just trying to help simplify. Oh, and the newer ecms don't like to be overwritten with a different file lol. Have a couple that we bricked experimenting :)


Do you have a pic of HP tuners for that file screen? I just don’t remember there being one for manual transmission to turn on or off reverse lock out.

[firebirdzig]

Honestly...I really didn't agree that your current ECU wouldn't work because it was an auto car. What type of ECU is it? E38/E67 etc?


Did you pin the socket on the harness?


I could be off base here, but an E67 is an E67....For example I have a E67 for a LS3. I have it running an LS7. Additionally, the GM harness didn't have a wire or a pin for the reverse lock-out and I added it and it works fine.

What do you mean by pin the socket on the harness?

[badazz81z28]

What do you mean by pin the socket on the harness?

Is there a reverse lock-out wire in the harness? On my GMPP harness, I had to build the wire into the harness and pin it for the connector to the ECM

[130fe]

I added the pin on my GMPP harness and then figured out how to “trick” The GMPP pcm to work with my magnum. The GMPP is a little different then the other GM pcms. The trans reluctor setting of 40 is locked in (because they assume you are going to use an electronic auto trans or a Super magnum (all are 40 tooth trans signals). If you are using a regular magnum, they are 12 tooth and an LS style t56 is a 17 tooth reluctor wheel on trans). If you use one of the non 40 tooth trans, it is super easy to reconfigure the programming with HP tuners. This is only the case with a GMPP PCM.

[firebirdzig]

Is there a reverse lock-out wire in the harness? On my GMPP harness, I had to build the wire into the harness and pin it for the connector to the ECM

The wire for the lock out is built in to the harness from PSI.