I replaced the TPS with a NEW one this weekend, because the P0120 TPS Circuit code constantly began coming on. I had replaced the original sensor with a Junkyard unit, and finally bit the bullet and bought a NEW in the box TPS sensor. Again this morning when the wife started the car, the CEL and Tranny arrow came on.. I reset the codes and she went on to school.

The only thing that may be different then weeks prior is I found out my wife has been using "regular unleaded".. DOh!!! I put premium in this morning for her but it was onlly 6 gallons...

Anything else I can try here?

 

Tech must be on vacation.... Crap, this is bugging the crap out of me.. i have to reset the codes every time I start the car..

 

FYI- I pulled the ECM and cleaned the Connection, no change as of yet...

 

Regular gas vs. premium won't cause this problem. Actually, it won't hurt anything other than reduce performance a little bit (assuming your car is an LPT and not an HPT- the HPT will see a larger performance drop, but it still won't be hurt.

As for the TPS code, you may have a wiring problem. I don't have the specifics here, but any repair manual/ Alldata will tell you the pin locations at the ECM/ TCM connector for the TPS wiring. Check for continuity at these locations with the pins on the TPS connector, and fix any bad connections. Hopefully, that'll take care of the problem.

 

Still radomly having to reset the TPS code....

 

I had a 850 that kept doing this and it turned out to be a bad ECU.

 

Help! Did anyone find a solution? My 1998 S70 has the same problem. Error code P0120. Flashing arrow and check engine lights. Replaced TPS and put in a new used TCU. After a few hundred miles lights still come on. Any ideas on what it could be?

 

I am an automotive tech for 7 years...new to this forum...only reason i joined was just to let you guys know that..... I am the "proud" owner of an 98' volvo s70...i recently replaced the engine due to an overheating incident,,,after replacing the engine which came with an intake and a tps of its own i started having a dtc#120 and arrow flashing accompanied by hard shift due to the ecm going into a dfault.....i went back and swapped out the new tps with the one from my old engine...this d i d n o t remedy the problem...i performed a full flow chart diagnostic which pinpointed the ecm/pcm/computer to be the problem....luckily the donor car i got the engine from still had its pcm/ecu/computers....popped them in and that solved that saga ! Remeber i did a flow chart diagnostic to make sure there were no shorts or opens in the harness between the tps and the ecu/pcm /computer !!! Goodluck !!!!

 

hi, new to this forum. have 98 s70 with flashing arrow+check eng lite on +transmission won't up-shift normally +lites on mode selector buttons flash alternately between E & W buttons. Had automatic trans. replaced 3 days ago. all ok for 3 day then problem! are probems related to tranny replacement?

 

It can be related to the injector relay going south. I intentionally pulled mine (anti-theft solution) and it disabled all injectors plus the TPS.