Hi. I have a 2007 E350, 5.4 gas engine, with 105K on it. I have been having problems not starting in park, and starting in neutral. Not knowing where to start looking, I posted in the van and electric forums. I was advised to try here. My replies mentioned both a TPS and a neutral safety switch. Not sure if they are the same thing or not. Are they? How would I know what is bad? Can it or they be adjusted, or with the age, is it better to just go get new? And do the new parts or part need to be adjusted? If so, how do I go about it? Also the trans was rebuilt at 88K. It has been fine except when this problem started, it had a shudder pulling out, which has disappeared.
Thanks for any help.

 

TPS is Throttle Position Sensor. The neutral safety switch is called the TRS (Transmission Range Sensor.) And no, they are not the same thing. The TPS has nothing to do with cranking in park or neutral. The TRS does. Either your TRS needs to be replaced, or the shift cable has some slop. It is common for the two #30 Torx bolts that hold the shift cable to the end of the shift tube on the bottom of the steering column to come loose. When they do this it is very hard to get the TRS to read park, so it won't allow a start in park.

Crawl under the dash and look up the steering column. See where the shift cable attaches to the shift tube? Tighten those two bolts.

 

Thanks for the information. I did find the bolts. They are tight. So I guess the TRS could be the problem. Can I test it, or isn't it worth doing? Just replace it? Is it just a bolt on thing? Or does it need to be adjusted in some way? Also, should it come from the dealer, or a place like NAPA?

 

It depends on which transmission you have. There is a tag on the driver's door opening Under TR is the trans code.

 

It says "Q"

 

That is the 4R75E. It's a simple change. Adjusting it won't help. the TRS needs to be replaced.

Block the wheels and set the parking brake. Put the trans in neutral.

Remove the nut that holds the shift lever to the side of the transmission. Don't remove the cable from the lever. Unplug the wiring from the TRS. Remove the two bolts that hold the TRS to the trans. Remove the TRS. Often it rusts to the shaft so it may take some force to get it off.

Install the new TRS. There is an alignment mark on the rotating part in the center that aligns with the mark on the TRS housing. Once they are aligned tighten the two bolts. Plug in the harness, put the lever and nut back on and you're done.

 

That seems easy enough to do. Even for somebody my age. I will let you know how I do.
Thanks so much for the help.

 

Mark, I went out this morning and made the switch. It was stuck on the shaft a bit like you said it might be. I used some WD40 on it and managed to get it off. Put it all together and it started right up. Hopefully that will be the end of the problem.
Thanks again.