scoob8000

I'm chasing a no TCC lockup issue. This is a 95' LT1/4l60E setup with 24x conversion.

I can manually lockup the converter by the controls in the VCM scanner, but never on it's own.

I tried logging all the TCC status bits. Two that catch my eye are:

TCC Ramp Exceeded (I get this soon as I start moving, but some folks have said to ignore it).
TCC Misfire Off - This is the one I keep coming back to. I'm logging all misfire counters and getting none. I've also maxed out all the misfire tables to test but that status bit comes on soon as I start the engine.

Can anyone think of other items to look at in the tune?

Kawabuggy

iTrader: (1)

How about brake switch issues? There are often 2 switches on the brake pedal.. 1 is for brake lights, the other is a TCC cancel & Cruise control cancel, switch. If there is a problem with that 2nd switch, the computer will never lock up the TCC. As a test, go out and drive somewhere safely and see if cruise control works. If my hunch is right, you will not have cruise either. You can use a decent scanner to check the status of the switch in real-time.

scoob8000

Cruise works. I'm logging that status bit too, I see where it disables the TCC when I'm on the brake.
I'm not sure if I'm barking up the wrong tree with the misfire status bit or not,,

scoob8000

Bump.

I'm still banging my head off the wall on this. I got another tune from a car setup very similar to mine (cam, converter, gears, etc) and copied just about everything over to a new file to test. Still no TCC lockup on it's own. But it still locks fine manually from the bi-directional controls.

Just to recap:
Logging all the TCC status bits. Misfire off and ramp exceeded are the only two that indicate they are getting in my way. Misfire counts are always at zero. All seemingly relevant DTC's are enabled. No codes are set. Cruise works fine.

rpturbo

iTrader: (47)

I had a similar issue. Mine was on a fresh built trans. In the end, I stuck a pressure gauge on it and it has very, very low pressure. Once I fixed that, it worked flawless.

scoob8000

Were you able to lock it up with the controls in the VCM scanner though?

truckdoug

iTrader: (26)

I had the same thing go on with the first iteration of my turbo truck. p01 pcm. i rechecked the trans wiring 1000 times. i swapped computers. nothing worked. I ended up just putting a switch on it.

this year I am using a p59, did another harness and it works. go figure.

rpturbo

iTrader: (47)

Yes I was. It was the weirdest thing. I ended up putting in a boost valve that had a O-ring in it and a new epc motor. It fixed it for months, now that its hot again, I am starting to have issues again. I am DONE with 60/65's. It's 80 time!