Transmission Range Sensor?

[Bodda]

I can't seem to figure out this problem on my new LC. It's a '94 FZJ80, fuel injection, automatic.

While in D, the RPM will not go above 2000. It stops right at 2000; hard ceiling. In P or N, the RPM behaves properly. There is no CEL.

I went to a local shop a couple of days ago, and after a day of testing, the mechanic said the problem is a faulty transmission range sensor. He pointed out to me that when D is engaged, the light on the dashboard doesn't illuminate accordingly. It does illuminate when L is engaged, and the RPM behaves properly. To further make his case, he also showed me that in 2, the dashboard light doesn't illuminate, and the RPM is limited. He said that essentially, the gears weren't engaging correctly.

The mechanic said this will be a long and expensive repair to undertake. Does anyone know anything about this who could tell me more?
I'm really stumped on this one; all your help is really appreciated!

 

[the stig]

The green light for the "D" is just burnt out. Mine is too, and so is probably 75% of the cruisers out there.

To be clear, you CAN rev the engine over 2000rpm when you are in neutral, but when driving, it won't go over 2000rpm? Does the transmission still shift? what about when you shift into 1st, 2nd, or 3rd??

 

[Bodda]

The green light for the "D" is just burnt out. Mine is too, and so is probably 75% of the cruisers out there.

To be clear, you CAN rev the engine over 2000rpm when you are in neutral, but when driving, it won't go over 2000rpm? Does the transmission still shift? what about when you shift into 1st, 2nd, or 3rd??

Thanks for your reply. I've noticed that many, many people have their D light burned out, but in this case it may be a little different. The P light is also out. The N light is usually out, but sometimes comes back on randomly. The D light is always out. The 2 light is out, unless you move and hold the shifter between 2 and D, in which case the light will illuminate, and you will feel the truck shift into 2. The L light is out, unless you slightly move the shifter in the L position until the light comes on. Very strange, right?

You are correct: I can rev the engine over 2000 RPM in N, but not in D. In D, the transmission does shift, but only one or two times. It doesn't appear to be starting from 1st, but I'm not 100% sure.

I've heard of people experiencing weird transmission glitches due to a faulty neutral safety switch, but nothing like what I'm experiencing. Is it a possibility?

Thanks for you help.

 

[the stig]

when you shift into any other gear, do you have the same problem?

 

[Bodda]

when you shift into any other gear, do you have the same problem?

I have the same problem in all the gears except reverse and L. Those are also the only 2 gears that have working lights on the dashboard.

 

[jonheld]

I would look into adjusting or replacing the neutral start switch on the side of the transmission. This guy tells the ECU what gear you're supposed to be in according to the shift lever position and it also runs the dash tally lamps and allows the starter to crank in N and P. If you can change the status of dash tally lamps by moving the shift lever fore or aft, then there's the issue.

 

[Bodda]

I would look into adjusting or replacing the neutral start switch on the side of the transmission. This guy tells the ECU what gear you're supposed to be in according to the shift lever position and it also runs the dash tally lamps and allows the starter to crank in N and P. If you can change the status of dash tally lamps by moving the shift lever fore or aft, then there's the issue.

Thanks for your reply, I was thinking the same thing myself. Do you happen to know a part number, or where I can find one?

 

[jonheld]

Thanks for your reply, I was thinking the same thing myself. Do you happen to know a part number, or where I can find one?

You need to consult with the keeper of the part numbers. @beno Onur knows all.

 

[Bodda]

You need to consult with the keeper of the part numbers. @beno Onur knows all.

I did some research online, and it looks like the part number is 84540-60010.

Can someone with more knowledge than me please confirm?