I've got a lexus GS350 that we purchased a little over a month ago.It had 31,000 miles on it Everything was fine until about 32,400 miles. Check engine light came on and car wouldn't shift out of 4th gear. I did put a transmission speed sensor in it and it didn't change.I carried it to a local Transmission guy and he told me he didn't think it was internal transmission. He thinks there is some other sensor not completing the speed for the transmission. The speedometer works fine and if I unplug the transmission speed sensor the car will not shift out of 1st gear,but the speedometer works. Could this possibly be a wheel speed sensor?

 

I am not real sure I understand why other than causing a short, but I found my problem. I had some quarter panel work that involved welding done about 4 months ago. I was checking the speed sensor connections in the right rear quarter area when I ran across this amplifier in the same harness. I unbolted it to plug and unplug connections and debris started to come out of it as I moved it. I took it out of the car and shook it out(attatchments). Put it back in and problems went away. It looks like the guy didn't cover it before welding.I am pretty sure it is just an amplifer but must have been shorting whole connection.


it is upside down