Transmision slip error code 1870

I have a 98 blazer 4.3l auto trans. my check engine light comes on with an error code 1870 which is a transmission component slipping. The only thing i feel with the trans is once in a while it starts to slam into 2nd gear but once you turn of the ingnition for a couple of second it will run fine again for a while,until it starts doing it again. Real spuratic no consitancy of time or milage. I talked to a couple of people with Chevy's and they had the same problem and a mechanic at a dealer told them this was the norm with these transmissions. Anyone have any other info for me? Please i'm loosing my mind.I just had the engine rebuilt and have spent about $4,000 over the last 6 months and it wont pass inspection with this problem.

Thank you

More than likely it's the valve body.

You can disconnect the battery for a few minutes to clear the code, get it inspected quickly, then worry about it. It is probably (as the previous poster said) your worn transmission valve body.

http://www.automotiveforums.com/vbulletin/showthread.php?t=338603&highlight=p1870

If you restart the truck and the problem goes away, its probably not your valve body, its either the PWM sensor and/or EPC motor. The computer is getting incorrect information, which it then set the 1870 and sets full pressure to the transmission, giving the slamming 2nd gear etc, etc. Take a look at these components before assuming you need work on your valve body.

This is a very common problem with the 4L60e transmission you have in your vehicle. The problem IS with the valve body, Specifically the TCC Regulator Valve(Torque Converter Clutch). A respectable transmission shop will fix this from anywhere between $200 - $400. I recently had this problem and called every shop in my town and asked how much they charge to fix the 1870 code. Hang up on the ones that tell you they have to rebuilt the whole transmission for $1500 bucks, I had quite a few tell me this and I told them where to go. They are trying to rip you off plain and simple. The place I took mine to said he does 1 or 2 of these 1870 codes per week and 95% of the time it's the TCC valve.

Be careful about clearing codes and then trying to get it inspected. When you clear codes you also reset the 7 monitors that most states look for during inspection (at least here in NY). these monitors test the oxygen sensore EVAP system etc. It may take several days to a week for the computer to command the tests and store the pass status for the monitors. In NY you automatically fail inspection if your monitors have not run.

If you restart the truck and the problem goes away, its probably not your valve body, its either the PWM sensor and/or EPC motor. The computer is getting incorrect information, which it then set the 1870 and sets full pressure to the transmission, giving the slamming 2nd gear etc, etc. Take a look at these components before assuming you need work on your valve body.


If this is the case, would a separate code (1860?) also be stored, indicating the PWM sensor malfunction?

My slipping problem goes away after shutting down only ~5 seconds & then restarting, but the only code that I ever find is the 1870 component slip.

Could it be the PWM failing, & it not set a code for some reason?

-Mike

I have a 98 Jimmy with 93,000 miles on it. After about 3 hours of hiway driving came to a stop light and it had the hard shift from 1st to 2nd. Pulled it over to the side of the road and turned off the ignition and started it and it was fine except the check engine light came on. Finally got home and the next day took my code reader out and hooked it up and it read P1870 twice. So i cleared the codes and searched the net and found out that this is more than likely a problem with the valve body. Took it to the trannie shop and they installed a rebuilt vavle body with oversized valves new spacer plate and did a full tranmission flush. Cost 495.00 dollars. No more problems. Be aware that if you let this problem continue on you can get metal shaving in other parts of your transmisssion and make problems worse. I would suggest getting the problem fixed before you get more.