So my daily driver/work truck just started throwing a p1870 code. Guessing this means its time for a rebuild on the 4l60E thats in it???
98 k1500 P1870 code???
- Thread starter BLUE72CAMARO
- Start date
DougD
Veteran Member
Nice, not sure I follow how he got that clip out from below but this sounds promising as that is exactly what mine is doing.
We had some trucks that set an 1870 and turned out to be an ign. switch failure. Replaced that code gone.
Yeah I dont think this is just an ignition switch, I have noticed the torque converter acting a little funny for a little while. The symptoms pretty much all line up with the fix that Doug D posted. I have the TCC part on order and the filter and fluid sitting on the bench for it so hopefully I can get that done this weekend and get it back in action. Worst part was I had my other truck loaned out to my dad while his is in the body shop for a paint issue from a repair a couple years back. I had to call him last night and tell him I needed the truck back as I didnt want to keep driving the 98 until I can try the fix above.
The guy I work with sent his personal truck out to have the trans rebuilt for that code only to find out the switch was bad when he got it back and had the same issues.
Did there trucks do it and throw the code all the time? If I reset mine it will only throw the code if I drive it for over an hour. I assumed this is how long it takes the trans to get good and hot. Did they have any other symptoms or just it throwing the code?
I just remember it was intermittent. He would test a lot of stuff, clear the code and it would come back the next day. He was/is not a very good diagnostic guy.
I have had a dozen or so intermittent switch failures on the 2008+ Tahoes. Not what I would call a pattern failure but not really unheard of either. The new stuff will give you a trouble code for loss of ignition and identify which circuit so GM knew it was an issue.
72'z'steve
Veteran Member
My 99 z/r2 beater at 252K started throwing a 1870 and real hard shifts after runs on freeway on way home from work last year,or pulling my utility trailer loaded,never around town If I turned it off,restarted,say at gas station it was fine for rest of the drive.After trolling the internet I bought a Modified TCC like DougD posted off ebay, was Teckpak A747410,threw in in on a whim,didn't need to drop the VB,fixed the issue {I think I watched that video with the white s-10 as a matter of fact.} the clip wasn't an issue that I remember because I have no flashbacks about it 
I hate "hack " fixes but been a year and still working fine! Later Steve!!
I hate "hack " fixes but been a year and still working fine! Later Steve!!
Put the TCC in last night, clip was a pain in the ass as none of my 50 pairs of pliers really fit in that little slot very well to spread the clip open from the bottom but I eventually got it. Drove the truck to work today and seems to have fixed the issue no convert locking and unlocking at speed as it was doing before. So seems to have solved the issue for about $60 with a filter/fluid change included.
