I have recently put my DTT noise filter on my truck to help with the ever so annoying problem of the TC locking and Un-locking due to eletrical noise spikes caused by the alternator that in turn affect the TPS...The filter I installed works good, cleared up most of the issue however, it (not nearly as much) will still sometimes play its tricks with the lock/un-lock. I did all the other things...Re-flash, APPS reset, cleaned connections and terminals...Here is my idea..What about taking the TPS wire (or wires) out of the wire loom all together? Running it seperately, on it's own and really insulating the wire...Do you guys think this should solve it or has this been tried w/ no luck...Opinions appreciated...

 

that was my first idea...take the wires out of the loom. a lot of members have posted about tcc unlock/loc problems. some say that cleaning out the tps takes care of it, or the noise filters, etc. but one thing that seems to always cure it is taking the wires out of the loom.

Tom

 

so what exactly causes the TC lock/unlock anyway?

 

When the PCM "sees" movement on the go pedal, it will unlock the TC to give better acceleration and less smoke. The PCM just "sees" voltage and if there are spikes in the voltage it will assume that you move the go pedal.

HTH

AlpineRAM

 

so has anyone attempted to do this procedure?

 

I was thinking about have a switch which would bypass the TPS sensor and input a fixed resistance (voltage) to the PCM, about 3/4 throttle. This would up the transmition line pressure to the torque convertor lock. I was going to try this for towing applications on the highway. :-

any thoughts? This is a similar idea? I have the 12V so only the Transmition uses the TPS.

 

vtailflyer: Well, actually the line pressure is not influenced by the TPS voltage- but by the throttle valve and it's cable. There is a product called something like torque-loc that pushes the throttle valve lever towards WOT position to increase the line pressure when locked up.
The APPS ot TPS voltage makes the PCM decide whether it will or won't ground the lockup solenoid. (which will then let ATF flow to actuate the TC lockup clutch)- so your switch would make the PCM think that you hold a constant throttle, nothing else. It would be simpler to install a manual lockup switch and have about the same effects and risks.

AlpineRAM

 

Alpine: Thanks for the explanation The throttle valve , is it something that is attached to the tranny and is moved by the accelerator? :-[

 

vtailflyer: The throttle valve is on the left side of the valvebody in the tranny. It is actuated by the bowden cable that comes from the inj. pump(12V) or the APPS holding bracket (24V).
In my opinion it proves worthwhile to look into electrical noise first, if the lock-unlock is cycling slowly- like 1-3secs locked- 1 sec unlocked. If you have a shudder like the TC lockup clutch slipping, then you'll have to look into the hydraulics side of the problem.

AlpineRAM