While passing another vehicle my transmission downshifted to 3rd, after passing the transmission would not up shift to 4th. I now also have two OBDII codes. P1870 (Manufacture Controlled Transmission) and P0765 (Solenoid B Crt Performance or Stuck Off ). Since the trans. won't shift into 4th and I have not had any other problems with this trans. (only 91700miles) I am guessing I have a stuck or malfunctioning 3 to 4 solenoid. I do not know where and how to get to the shift solenoids though. I.E. are the accessable though pan or does the trans. have to be pulled?

 

Hello,

If the trans shifts 1,2,3 then solenoid is not bad. You have 2 shift solenoids. SSA control the 1-2 and 3-4 shift, while SSB controls the 2-3 shift. They are in the side pan, you just about have to pull it out to get to them. So, if it is shift 1,2,3 and no 4th, the 4th clutch hub is stripped. This is very very common, they all do it. 4T60E and 4T65E transmissions. The P1870 code def is an transmission internal component slippage. Basically it doesn't see the rpm's dropped when it commands 4th gear. Hope this helps.

 

Oh sorry, the P0765 code for solenoid B is a performance code, like it says. The performance is not being performed as commanded because the clutch hub is stripped.