tps grounds on renix

does the TPS (throttle position sensor) on an 89 with an automatic have separate grounds? meaning one for the flat 3 wire side (engine management) and another for the square 4 wire (only has 3 actually) for the transmission control. i know the flat 3 connector has a ground wire, which i have added a better ground to since i was getting a little too much resistance. now i have none with the new ground. but when i test the 4 wire side, the (D) pin which i assume is the ground is showing 650 ohms from pin to neg side of battery. can i put another GOOD ground wire on the transmission side like i did with the engine management side?

i cannot get both side to get within spec with a new TPS. either i set it with the engine management side to spec, or the transmission side to spec. but not both. i think a better ground to the trans side may fix this, but do not want to mess up the ECU by grounding a wire that shouldnt be.

Ding, ding, ding!!!!! YES!!!!!!

You just discovered one of the deepest darkest secrets of the Renix automatic TPS!!!! You get 10 brownie points sir!!!!!

I take it you have not read, or forgot what you read in the "RenX Files" thread I wrote 5 years ago here?

Took me 2 years to figure that TPS-dual ground issue. Mine had bad grounds on both side, AND the TPS was perfect on the engine side I was testing, but was way off on the AW4 side. It ran like a little old lady up shifting at 1200 rpm, and was in 4th gear by 25 to 30 mph at WOT. Took 3 minutes to get to 60 mph when I bought it.

IIRC, I used the same, single, new ground on both sides of the TPS, directly to the battery negative post on all my Renix jeeps.