Thread: p1870 code
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Old 07-02-2010, 04:31 PM   #2
transman618
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Re: p1870 code

Quote:
Originally Posted by houndog3 View Post
1997 k1500 4x4 im getting a code 1870 using actron cp9125..any help would ve great
P-1870 "Transmission component slipping" Very common problem in these transmissions. You are probably getting shuddering at highway speeds and harsh 1-2 shifts after it warms up. 99% of the time its in the valve body. The TCC (Torque Converter Clutch) regulator valve in the valve body has worn out its bore and ATF is leaking by the valve causing decreased line pressure to the converter clutch and causing the converter clutch to slip. Computer sets P1870 and maxes out line pressure to protect the transmission from destroying itself. This is why you get the harsh 1-2 shift. The fix for this is to either replace the valve body with a GM reman or install a new TCC regulator valve and sleeve kit which requires reaming the valve bore, installing a sleeve then a new valve. Dont let this go on too long or you can destroy the converter.


transman
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