99 jeep cherokee classic, aw4 transmission, 235000 miles, new to me about 4 months ago. Check engine light came on shows a code for " transmission sensor A circuit", not sure of code number, done at advance, he said it didn't show code number. Anyway, trying not to throw parts at it. Trans shifts perfect, odd part is will not shift into overdrive, but only sometimes. If trans doesn't shift into od you can stop, put into park, turn off engine, restart and will go into overdrive. Likewise if it goes into overdrive when you start out, go thru same stop procedure and it will not shift into overdrive. Have tried this about 30 times and same everytime. Does not matter if it is hot or cold. Seems more electrical to me but I am more mechnical than computer. Suggestions appreciated. Should I throw new selenoids in or keep looking for another problem. No other codes in computer. Took it to a transmission guy, he suggested throwing parts at it.

 

Suggest you go to a different store to have the codes read. That Advance Auto Parts store isn't doing something right. Their code reader should show a code. A full code is needed.


Transmission sensor A circuit doesn't make sense. If they are referring to shift solenoid A, that's the 1-2 & 3-4 shift solenoid which have no effect on overdrive. Solenoid C is the overdrive solenoid. See pic.


Need code(s).




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Thanks for the reply. I will get that done and report back.

 

For those interested. Living in rural area not many options for a scanner. Borrowed used TPS from neighbor, seems to have fixed issue for now. Ordered new TPS, gonna try that for now.

 

Make sure you get OEM. Aftermarket TPS units have a high failure rate.

 

Replaced TPS and checked voltage at wiring connector, all is good no more code. Now shows code P0705.
PO appears to have replaced NSS , looks new. Anyone have any luck with these aftermarket ones? Worth trying to repair like a stock NSS?