p1870 code what does it mean?

[truck150]

my reader says trans component slipping what does that mean please help me i just bought the truck it is a 96 half ton

[777stickman]

From my '98 C/K GM manual.

"Internal transmission failures could set a DTC P1870"

Basically that means there is slippage in your tranny that the computer is sensing.

1st thing to look at is the TCC
Say your going 60 MPH and give it some moderate gas, the tach should show an increase in RPM's as the speed increases. If it shows an RPM increase as soon as you hit the gas pedal then the TCC is faulty.

2nd thing is the 1-2 and the 2-3 solenoid valves.

Really only good way to diagnose this is with a good scanner that can access the tranny module in "real time".

[truck150]

what is a tcc and where would i find it. Also when you say moderate gas how firm of a push do you mean? are you meaning to make it down shift or just enough to not make it down shift

[777stickman]

Originally Posted by truck150

what is a tcc and where would i find it. Also when you say moderate gas how firm of a push do you mean? are you meaning to make it down shift or just enough to not make it down shift

TCC=Torque Converter Clutch.

Just enough throttle to increase speed without downshifting from 4th gear at 60 mph.

All items listed previously are internal in the tranny.

As stated, a high end scan tool is needed to access the tranny computer module for proper diagnostics.