I am going to be helping a fellow member troubleshoot his car this week. It is unlocking intermittently.
I have read the stickies and done a search. I have read that I can physically connect an LED to the black/tan wire and watch for it being lit. I am not sure he wants to do this; IDK until I talk to him.
I have two scan tools, Autotap and Snap-On's Solus.
I have read in the search that I can monitor whether the lockup is being commanded, but the parameter name is never mentioned. Does anyone know of then name of this parameter(s)?
I am very familiar with scan tools, having used them for 15+ years. I just need to know what to look for and the value of said parameter(s) in each case (commanded ON vs. commanded OFF).
Thanks.

 

Not sure what it would be called on the solus scanner, but there are 2 solenoids that work together to apply the tcc. So there will be 2 parameters to watch, TCC- enabled or disabled TCC PWM- will be in a % starting low and will move up to about 98-99%. Hope this helps

 

If the trans is stock or PWM has not been modified you will need to look at two things
TCC enable disable and PWM (TCC DUTY CYCLE) .
If PWM has been mostly or totally eliminated you would need only look at the TCC enable.

But even then you cannot be sure unles you verify with for instance the LED test if its actually happening .

However most of the time I have noted that and intermittent lock/unlock without a code usually ends up being engine miss fire.

Good luck

 

I was afraid of that. Autotap (which I have used quite a bit) has the PWM parameter, but the car has been tuned, so it may have been tuned out. (can't tell until I have the vehicle, of course).
There is also a transmission parameter called Pressure Control Solenoid Duty Cycle. Would this be at least one of the solenoids?
I'll be pulling out the Solus tomorrow and checking it out. I haven't used it , but it is mainly a bus monitor, which I have used in lots of flavors.
Monitoring misfires is easy; I saw you looked into this parameter almost automatically (no pun intended).

Where is a good place to tap into this harness? I am sure it goes into the side of the tranny (right side, IIRC) but is there a better place to tap? I can go back and read the search items as far as how to hook it up, but I'll have to sell the idea to the vehicle owner prior to altering his car. I have all the equipment, except for the LED itself, so the wiring is no problem for me.

 

No you are only interested in the TCC solenoid .
As for the LED get a 12v one from radio shack .
You can find the wire at the PCM but I find its easier just to grab it at the trans harness plug .
Still the MISSFIRE is what I would look at first.