i got this code yesterday from my 2000 blazer . it got very clean oil, level and never pushed hard but o well **** happens right. i was looking around the internet and reading some tech documents about changing the tcc solenoid (regulator) spring with an aftermarket one or a tube instead of the spring will fix this issues in some p1870 cases. well i want to give it a try but I never mess with the valve body before, so my question is if i can do it without removing the transmission and were do i buy the tcc solenoid . i have read a lot of documents doing this but none of those mention removing the trans, and for the pictures it seem to be a pretty easy fix. . any suggestion, comment, help is appreciated

 

The spring alone won't fix it. If it has low mileage, you can get by with updating the valvebody. That will require a special tool to bore out a valve bore, and install a new valve and sleeve. I would suggest taking it to a reputable transmission shop, and letting them do the update.

 

There are several ways to address this code but they all require removing the valve body which can be a task by itself. One thing you might consider trying before you remove the valve body is changing the filter and fluid and replacing the PWM solenoid while you in there it can be changed without valve body removal . The screen in it can become clogged and create this symptom. But in many cases the converter regulator valve (PWM VALVE) wears the bore in the body and dosent seal properly any more. Transgo has and sk kit that addresses this without special tools. Also in many cases the spring and or tube you mentioned will take care of it both of these effectivly eliminate PWM and change the lockup strategy to a simple on/off which is much better in my opinion.

 

thnks for your answers .
so you recommend to change oil, filter and replace the pwm valve (or transgo sk)? and see how it works ? and this can be done without removing the valve body right ?

 

btw i got a '00 blazer with a 4.3l and looking around the internet i found the transgo kit. T74165E(think this is the right one):

# SK 4L60E Shift improvement / correction kit Corrects/Prevents/Reduces: No lock-up or 4th and code 1870. Cutloose & bang from reverse to drive; forward and low/reverse clutch burnup. 1-2 bump; double bump; slide-bump; delayed reverse engagement hot. Includes new design PWM boost valve. Also corrects worn valve body, rough shifts and blinking light. No special tools needed.

 

That would be the kit would replace the PWM solenoid and install that kit ideally.

 

ok i will change fluid + filter tomorrow and take a look under there to identify all the parts and snap some pictures. thnks

 

There are at least two reasons for getting P1870. One is an
actual hardware problem.

The other is, spending enough time in a TCC-slipping area of
the driving envelope to exceed the slip-limit thresholds for the
code to pop. At light throttle you may just not see the PCM
command adequate line pressure, to supply the TCC the
pressure it needs to hold. Drag a boat trailer up a mile long
light grade, say hello to the gopher. Seen that, only without
even pulling a trailer.

It would be good to know whether you have a full time or a
one time slip problem, but that needs a scan tool that logs
data.