weird TPS reading and limp mode

[brandonf90]

so i was testing my tps to see if its good (tranny limp mode) anyways i tested it via haynes manual, i set the closed resistance to .9 (then tightened it) but when i set the throttle body all the way open i was getting 4.2-4.3k resistance. i know its supposed to be 5k but would that contribute to my tranny going into limp mode? also when i would be setting the tps id get it set to just around .9 but i barely tap it and it will jump to 1.7k or so. what im asking is this telltale signs of a bad TPS ?

 

[blktalon3]

Your tcu is probably bad causing limp mode. Another thing with the tps, a bad tcu can screw with your tps readings. The tps circuit somehow runs through the tcu and if it's bad can make the tps act like a bad one. It happened to me once and I replaced 2 tps sensors before I figured out it was the tcu.

 

[hotrodssnova]

Your tcu is probably bad causing limp mode. Another thing with the tps, a bad tcu can screw with your tps readings. The tps circuit somehow runs through the tcu and if it's bad can make the tps act like a bad one. It happened to me once and I replaced 2 tps sensors before I figured out it was the tcu.

Wait a second! The ecu and tcu do not communicate. The tcu gets all its information from the tps, the vss (speedo), tach, and throttle position switch (on/of switch on the throttle body closest to the firewall. .green wire)

I would pull the tcu plug and set the tps. It's tied into the ecu and the tcu. Then report back.

 

[brandonf90]

Your tcu is probably bad causing limp mode. Another thing with the tps, a bad tcu can screw with your tps readings. The tps circuit somehow runs through the tcu and if it's bad can make the tps act like a bad one. It happened to me once and I replaced 2 tps sensors before I figured out it was the tcu.

i test my TPS with the throttle body removed and not plugged into the car. im just reading direct resistance from the TPS prongs.