Hey everyone,Thanks for helping me in advance! I have a 1989 f150 4x4 351w, I am not a machanic but I do enjoy working on my truck. The problem I am running into is a KOEO code 53, which according to my Haynes manual is TPS above Max. volts.I Checked the volts going from the PCM and it is 5 volts, and I believe the ohms checked out on the sensor side(can't remember exactly what the ohms were but pretty sure they were close to the manual).When i did the volt check with key on and throttle closed i got like 5.o volts(should've been under 1, right?) way high. With this info could my TP sensor just need adjusting or do ya think the sensor is shot? I also thought I saw an older post when i was searching for answers that said the wire harness should point towards iac my manual say pointing away from the IAC then turning clockwise to adjust! Thanks again!

 

I found a link on someone's post that talks about the idle being correct with a TP sensor out of range to correct the voltage and then adjust the set screw to match(pretty sure my set screw has already been messed with).All that withh the IAC unpluged and my spout on the TFI unplugged as well.So I am going to loosen my Throttle Body, try adjusting my TPS to under 1 volt and if it don't work I will replace the TP sensor! Has any one adjusted a TPsensor 4 volts worth? How much do the volts move with adjustments,is it just small adjustments that move the volts alot? How bout this has anyone seen a TPS on backwards or is this even possible?Thanks for any replies.Happy Easter Too!

 

You have 3 wires. 1 wire will be the 5 volt wire you mentioned. One of the other wires (probably green in color) is the one that you should be checking and it should display something between .5 and 1 volt. If it is above 1 volt, that's when you will have problems and may possibly be adjusted by that screw to bring it below 1 volt, that's what you'll have to do. If it can't be adjusted using that screw, you'll need a new TPS. You will always have a constant 5 volts from the other wire you mentioned and that's not the one that should be checked for voltage. I would say to shoot for setting it to somewhere in the mid .80 voltage range to the low .90 voltage range if the TPS is not defective.

 

thanks for repying, turned out to be a bad TP sensor and not adjustable.So i cleaned the TP and the IAC and then put on the new TP sensor.Then I reset the base idle and its running the best I have ever seen this truck run!I did check the volts on the new TP S when I put it in too and it hit right in range! Thanks for all the support and info on this site!