QUESTION: Hello Roland. my engine light came on about two weeks ago. i have access to a code reader and it listed P0871 which said trans fluid presure sencer switch C. above 30 mph it seemed to have a hard time shifting to the next gear and having the rpm drop. i tried auto stick and it seemed to drive fine. i took it into a shop my employer deals with. this is what he came up with. he said that there were other codes associated with the first code that being P1776 - solenoid switching valve stuck in 1/R position. he listed set conditions as TCM sences 1/R pressure switch closing when attempting to engage- Gear - neut L-R press sw - open. as for the first code ( P0871 ) he states code sets when one of the pressure switchs are open or closed at wrong time in a given gear. he dropped pan and said fluid smelled bad and that there were metal shavings in trani, im assuming it was in the filter. he said there were very little shavings but its uncaracterisic of this type of car. work that was done: flushed system , replaced filter and cleared codes. one hour after driving it home engine light came back on. does this information point to a rebuild or perhaps just pointing to replacing solenoid? please advise.
ANSWER: Hi Steve, Neither of those codes points to a rebuild as the necessary repair. Each code has about a one dozen test procedure (several of which are identical for the two codes) to sort out the solution. The possibility of a wiring problem is cnecked out first. Then the repair points either to a problem in the valve body or the pressure switch assembly. To get to the pressure switch assembly one first has to remove the valve body and those are located inside the transmission. So both possibilities can be examined in the same procedure. It involves dropping the pan and then removing the body and then the assembly. I have a CD for those pages that cover the test procedures and could copy those and attach them to an email which I would send to you directly. If you aren't going to do this yourself then the most important choice is which shop has the capability to do this job. I can also copy the pages about removing the valve body and assembly if you want to do it yourself or have a competent person who doesn't have the manuals. But opting for a 'rebuild' does not seem to be warranted at all. If you would like the test procedures and/or the removal procedures let me know your email address but don't use the @ symbol, rather us "at", or the address is blanked out. Please 'rate' my answer (see below). Thanks, Roland
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QUESTION: thank you Roland for your detailed response. please email me the answer along with the test procedures. i want to rate you but second email i received doesnt have that option button. do i need to reply back to first email link? please advise.
PS. you would suggest starting with the wiring test first to rule any wiring issues out? and these wiring issues are inside or outside the transmision ? thanks. i look forward to Rating you for sure
Hi Steve, You will see another chance to rate/nominate me at the bottom of this response; thanks for the first rating and kind remarks. The wiring is tested via the external sockets/harnesses on the transmission, but of course the solenoids/pressure switches are internal. If you follow the procedures I believe they generally do the wiring tests early on. When you send the follow-up to this, do specifically tell the email address (using 'at'). I will do the copying and mail this evening as my afternoon is committed to another activity. Roland