any updates on this? I'm having a similar issue were I can command lock up via scanner but it wont lock up thru tune. this is a ls2/4l75e
any updates on this? I'm having a similar issue were I can command lock up via scanner but it wont lock up thru tune. this is a ls2/4l75e
Hello, I am currently in the process of doing a 5.3/ 4l80e swap into my c10 truck. I found some information that i thought was useful when doing the wiring for the TCC control http://lt1swap.com/wiringharness.htm. I have yet to verify if i actually works but food for thought.
Brake Switch Signal - For automatics with lock up converter, the PCM needs signal when brake pedal is pressed. However, the signal needed is opposite how you're brake lights work. The PCM wants 12v+ constant on this wire when brake IS NOT pressed, and OPEN Circuit when the brake IS pressed. If you vehicle was equipped with a lockup trans to begin with, you probably already have the proper normally closed switch mounted by your brake light switch. If you do not, you can use a relay to perform the same thing. On most relays, there are 5 terminals, 2 of them turn the relay ON when provided ground/power. There are then a normally open leg and a normally closed leg on the relay and a supply. By feeding 12v+ on the supply leg, and hooking the Brake Switch Signal wire to the normally closed leg, you will now have the correct signal for the PCM. When the brake is pressed, 12v+ flows to brake lights, tap into this wire, and run it to the relay to turn the relay on. This will cause the normally closed leg to become open, thus turning OFF the 12v+ signal to the PCM. When you release the brake pedal, the relay will turn OFF, and then feed 12v+ to the PCM.
Wiring Diagram:
relay_diagram_stop_lap_relay_for_tcc.jpg
Hope it helps
I've found similar information regarding this "workaround", but I'm hoping that someone has found a resolution via tuning. Seems there's a "signal/switch" that can be "inverted" via software. But, maybe that's just wishful thinking.Originally Posted by Sandman155073
**Capt. Ron - 7th Dist. Fire**
Discussed possibilities with tuners & 24x kit makers. One thought is that it's the PCM used. Though it appears that V6 & V8 vehicles may have shared the same PCM part number, the ones originally in the V6 vehicles may have issues with lockup of the TCC. Another thought is that Bryan and/or Keith may have found a switch within TunerCATS that may have an affect on how the brake switch signal is interpreted. Neither theory has been confirmed (yet). That's the latest I've been told, as of this morning. ;-)
**Capt. Ron - 7th Dist. Fire**
So nothing on this yet. I can?t figure out my issue either.
any updates I have the same issue (94 impala wagon with lt1/torq) and the tune looks fine, same brake switch readings, while I tried riding the brakes over lockup speed it still doesn't lock while tcc brake off says yes
Reach out to Paul form Torqhead if you haven't already. In my case a new PCM resolved it, but we're not sure if it's due to the way it was flashed with Tunercats or something burried in the PCM from it's original application.
Which PCM are they starting with? FWIW The PCM I am using which TCC works is sourced from a 2002 Pontiac Firebird Formula/Trans Am/ 5.7L 8 Cyl. GM_PO1. Operating system 12212156 -> 1251002 Speed Density - 2 bar (RTT). Don't know if it makes any difference just thought I would throw it out there.
scoob800, posted just before I did. Which PCM are they starting with? FWIW The PCM I am using which TCC works is sourced from a 2002 Pontiac Firebird Formula/Trans Am/ 5.7L 8 Cyl. GM_PO1. Operating system 12212156 -> 1251002 Speed Density - 2 bar (RTT). Don't know if it makes any difference just thought I would throw it out there.
So the reasoning is still a mystery
I did a segment swap this morning and fixed it, theres something i cant see in hptuners causing it, tqhead said that tunercats could change it, but segment swap solved my issue
I'm going to test this out as well and report back..
Interesting
Daniel,
I chatted with Paul on yesterday afternoon about the segment swap. Tried it this morning with no success. Not giving up on it. He'll be sending me another PCM that he'll confirm as "good", using HIS personal Impala as the test bed. If it works on his, it should work on mine. Will be up to a couple of weeks before I can report back, as Paul's been inundated with orders this month. Also, he's wanting to examine internal components (IC's, modules, etc) to ensure identical components were used from GM.
Sourced vehicle was the following:
2002 Pontiac Firebird (8 cyl), 2G2FV22GX22000000 0411, (GM: 2)
**Capt. Ron - 7th Dist. Fire**
Hopefully that will work for you. Just curious, what is the sourced vehicle of your current PCM?
Also would like to add for others that find this thread with the same issue with an update like this can you provide a sourced vehicle and info as to your success so other have some idea as to what works what doesn't. I also had some issues, the first PCM was for a DBW not the DBC I needed. Bought another form the same years and also bought all the credits for that model year so I wouldn't have to keep eating up credits while I was trying to find what would work and what wouldn't.
So, life has been quite busy lately. Haven?t touched the car in two weeks. But, am hoping I have something in-hand tomorrow. As for the source vehicle, I have no clue. Am told that the units are received from various vehicles.
Will post up results once I have the new PCM installed & have test driven to confirm the ?fix?.
New ECM installed. Paul (@TorqHead) found the issue, internally to the unit. Resolved the issue, and now have fully functioning TCC.
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