Can someone look at my log and tune? Another TCC questions.

[TransGo Robert]

Inside a computer you have something called driver's, it is like a light switch if you want. That is what the computer use to provide ground to the circuit and turn ON the solenoid. It sounds like yours is bad. The only other thing that could do it is your tune is not script right, I don't know anything about tuning so maybe there is a way to set it up wrong. Like for example the 4L80E does not use that solenoid, it only has the PWM solenoid. I just mentioned that because it is a dark hole for me, I don't know if that's even a possibility. If it was a stock vehicle and computer, the diagnostic would be done, 100% sure bad computer unless you were piercing the wire insulation to take your readings.

[Awheeler]

Yes, a black hole for me as well. Anyone know if the tune attached earlier has the TCC properly set up?

[Awheeler]

I am going to trace the pin to the trans. Anyone know if the wire isn't connected to the trans plug, if it will always show 14.5 volts? Beginning to think this is yet another wiring issue.

[TransGo Robert]

With the transmission connector unplugged it will have nothing on that wire if it is wired correctly.

[Awheeler]

That is a helpful tip. Will pull the connecter and test. If still has power, time to start tracing wires.

[Awheeler]

Was able to test continuity and both PIN 2 to PIN U on the transmission plug that controls the TCC PWM solenoid and PIN 42 to PIN T on the transmission plug that controls the TCC. All checked out. Anyone have an idea why PIN 42 volts are not dropping?

Anything missed?

[TransGo Robert]

Was able to test continuity and both PIN 2 to PIN U on the transmission plug that controls the TCC PWM solenoid and PIN 42 to PIN T on the transmission plug that controls the TCC. All checked out. Anyone have an idea why PIN 42 volts are not dropping?

Anything missed?

Obviously the computer is not commanding it. No need to check continuity or anything like that if the voltage remains high on that wire. The problem is 100% on the computer side.

[Awheeler]

Robert, you are going to get tired of hearing from me!

I am trying to find a creative way to go about fixing this without changing the ECM. Does PIN 2 and 42 both need to be reading lower voltage? If 42 is grounded and 2 still reads 12 volts, will the lockup engage? Thinking about wiring in a switch or relay to ground PIN 42. Would be great to just ground pin 42 if both 2 and 42 must have low volts for the engagement. If just grounding 42 engages lockup, will need to think more carefully.

[TransGo Robert]

Robert, you are going to get tired of hearing from me!

I am trying to find a creative way to go about fixing this without changing the ECM. Does PIN 2 and 42 both need to be reading lower voltage? If 42 is grounded and 2 still reads 12 volts, will the lockup engage? Thinking about wiring in a switch or relay to ground PIN 42. Would be great to just ground pin 42 if both 2 and 42 must have low volts for the engagement. If just grounding 42 engages lockup, will need to think more carefully.

Pin 42 and pin 2 are two completely different circuits and work independently from each others. Pin 42 is the lock-up enable solenoid, that solenoid reverses the flow into the converter enabling lock-up. On pin 2, that's for the PWM lock-up solenoid that controls the clutch apply pressure up and down to get the slip rates the computer aims for. On yours, it goes up to 99% and just stays there because it is trying to fix the problem but normally it would go only to 35-45 % under normal driving conditions.

[Guy With A Chevy]

2000rpms at 65mph I dont think there is a single issue. Sounds like a ratio problem to me in the tune. Is the speed correct as in the log?

[Awheeler]

Wanted to provide a quick resolution to this issue in case anyone else encounters the same thing. Robert is 100% correct. This is an ECM 'switch' issue in circuit 422. I did trace wires and found a few things that needed to be sorted out, but did nothing to fix the issue. Also checked every table in the tune and found nothing to fix the problem. So, I put a manual switch in line on PIN 42, the tan / black wire. Nothing fancy, just the tan / black wire to an 'on / off' switch to a ground. Went for a drive and as soon as switched to on, the TCC locked. Switched off and unlocked. Everything works perfectly except for the volts that come from circuit 422.

So, two ways to fix - 1. new ECM and 2. manual switch. I am going with option 2 for now, until I can work a few other things out before a new ECM.

Robert, thanks again for all of your patience and advice. I would have never gotten to this point without your input and suggestions.

[TransGo Robert]

Wanted to provide a quick resolution to this issue in case anyone else encounters the same thing. Robert is 100% correct. This is an ECM 'switch' issue in circuit 422. I did trace wires and found a few things that needed to be sorted out, but did nothing to fix the issue. Also checked every table in the tune and found nothing to fix the problem. So, I put a manual switch in line on PIN 42, the tan / black wire. Nothing fancy, just the tan / black wire to an 'on / off' switch to a ground. Went for a drive and as soon as switched to on, the TCC locked. Switched off and unlocked. Everything works perfectly except for the volts that come from circuit 422.

So, two ways to fix - 1. new ECM and 2. manual switch. I am going with option 2 for now, until I can work a few other things out before a new ECM.

Robert, thanks again for all of your patience and advice. I would have never gotten to this point without your input and suggestions.

Thanks for the update, and glad you got it working for now until you can replace the computer.