1991 LS400 Shifter won't move out of park

[jp6296873]

Hey all. I've got a 91 LS400. I have an issue with the transmission shifter. When I bought it, I had no issue in shifting it out of park by simply pressing the brake pedal, like any other car. I've noticed that now the shifter won't come out of park unless I press on the shift lock override button. When I do that, it moves just fine until I put it back in park, then it becomes locked again. I've read on some forums that it could be the brake light switch, but the switch doesn't seem to be the issue as the brake lights work just fine. I had also read that it could be the infamous wiring harness in the trunk hinge, I had two broken wires there that I fixed but that did not solve the issue either. I have hard it could also be a shifter solenoid that's located in the shifter assembly. Can anyone else back up this claim about a shift solenoid being the issue? 

[94_LS400_GREEN]

It’s probably the shifter solenoid/actuator. Usually in most cars, when in park you can hear a small click when you touch the brake pedal. It seems that has probably failed. I haven’t had this issue so not sure how difficult it is to replace but you’ll probably have to remove the trim pieces and the shifter. Not so sure about the whole console.

[Jeremy M.]

The way to test the shift lock solenoid is to pull out the trim on your center console. There will be two wires going to the solenoid in your shifter assembly, and you'll check that you are getting both power and ground (12V) to those wires when the key switch is on and brake pedal depressed.

If you have power and ground, but the shifter will not leave park, you know the solenoid is bad. Depending on how difficult it is to access the solenoid itself, it may be easier to get a whole shifter assembly from a junkyard.

If you are missing either the power or ground, you'll need to find a wiring diagram for your car and follow the circuit to see what other components act on it, and to test whether any other associated switches or fuses are OK.