So, my car suddenly would not disengage from park, or go into reverse from drive without pressing the shift lock release button.

I have changed the brake sensor and checked all the fuses and the brake lights do work.
I searched around without any luck to the solution, so I decided to try changing the Computer Sub-Assy, Shift Lock Control part number 85903-30020



Looks like this, it looked to be held by 2 screws and 1 harness and by the linkage







Hesitant in changing this out since I had no previous experience, and my mechanical skill is average with just light tune ups, brake jobs, and suspension knowledge.

First start by removing the ashtray, simply pull towards you and disconnect the harness for the light and lighter
Then, remove the shifter bezel by pulling up from the back side as pictured and disconnecting the 3 harnesses for the PWR/ECT/SNOW, Heat Seats, and VSC OFF buttons (your car maybe less if non heated seats



You are now exposed to this, accessible are 2 bolts for the shifter assy, and harness for the culprit shift lock control assy and 1 screw for it



Now remove the top portion of the shifter assy held by just 4 tabs in each corner



At this point, I went ahead and removed the harness from the control assy, and the 2 exposed bolts for the shifter assy, but it did not budge



So, decided to go further by removing the 2 nuts on the left side to take apart the shifter assy further




Pull out the pin, becareful not to lose the shift release button lever



Shifter assy further exposed, but found out the other screw that is holding the control assy is screwed in from the bottom, meaning that I had to remove the whole shifter assy…
That means I need to get to the other bolts holding it

Pictured below is armrest already removed, but simply remove the bottom section first held by 2 bolts, and the power inlet, then the top portion of the arm rest is removable held by 2 other bolts.

Now pictured is the center console ready to be removed held by 2 screws up front, and 2 bolts in the middle



Pull it towards the back and it should pull off



then next you need to remove the rear AC duct held by 1 screw in the middle and 1 screw in the back



Now the other 2 bolts are exposed holding the shifter assy



The shifter assy is held by total of 4 bolts, the nut for the shifter linkage, along with the connector for the control assy, and harness for the shift indicator light, and harness the main harness is clipped on



removed



Bottom of the shifter assy where that 1 screw was…


Also held at the linkage with this black piece




Carefully remove and you can proceed with reverse of the order for installation



There maybe other order in removing this piece but this is how I attempted it, and without previous knowledge in how to and with intermediate mechanical knowledge, it took me approximately 3 hours

Portions that I was struggling was the shift linkage part, where it has minimal clearance for it to slide in and out

Upon replacing, you can see the shift lock button moving upon pressing the brakes
so if you can't put the car into gear or get out of park or into reverse from drive position, this is maybe another solution in fixing it if you have good brake sensor, fuses and lights are working

Hope it helps, and good luck!

 

Nice, I need to do this.
I've had a wad of paper jambed in the shift lock release button for years, now I have your informative writeup.

thanks

 

Nice write up with clear picture, thank's , did you try already with the shifter? is everything work again?.
I still waiting for my parts, hopefully I can do it.

 

I forgot to ask you, did you have to put some fresh grease with the new installation? when I take out the cover on shift assy, I saw some grease ( yellowish) color by the shifter, if you do what kind of grease you use. Some people mention don't use petroleum base grease.

 

yup, I came across your reply to one of the past threads,
and that's when I thought we needed a writeup lol

No problem my friend, it is working as it did from the factory now, all fixed! yeah!

I did not regrease anything, I guess it was left over grease from before,
keep us updated with your replacement if it fixes the problem

 

Lol...I did the exact same thing....

 

 

good write up man, appreciate you putting it up!

 

Finaly, I'm finish replacing shift lock control. Now everything back to normal. I also replace the cover slide since mine broke off right in the middle.
Takashi, you're right, I was little struggling to take off the linkage, and the center console. It was good so we can clean all the dust under the AC duct too.

 

If you still have the old part, it would be nice if you could take it apart as far as you can get and take pictures of it, maybe there is an easy fix with a 3$ component possible.

 

Is yours bad too? Hope it does help if you do decide to change it

It's great to hear that you had the chance to replace the part, I told you about the linkage lol
and my slide cover also broke in half lol, but I just decided to delete it lol
Yes it is a good idea to clean the parts and area while you have room

I think I do have the old part, I may look into dismantling it to see what's going on in side

 

I want to thank Takashi and Kretek for their great write-ups. This really saved my ***. Having disassembled the shifter subassembly twice, I was able to quickly pull it out. The trick was installing the new computer subassembly. It has a long black finger with a loop that must catch on a horizontal post in the shifter. That took a while. Thanks again for the help, I saved some serious $$$$$$$.

 

Takashi, hope you and others can shed some light here.

Pasting from my New Thread.

99 GS300.

I left it sitting for 5 months and went overseas. After returning I found dead battery, charged it, but couldn't get the car out of Park or into R unless using manual shift lock button. Pain in the ***, obviously.
So I checked all the fuses in the the foot-well and next to battery-all are fine.

Today, went to a junk yard and got the entire shift assembly with shift ECU included, (it looks like silver radiator with white connector), took the ECU unit out of junkyard's shift assembly and swapped it into my assembly. I didn't see why I should swap the entire assemblies in one peace as everything inside beside the ECU unit is purely mechanical parts- plastic and springs.

So after the swap things got even worse: The car doesn't switch to D and L but switches into all other gears, but D and L are just bypassed. Car drives in 4th now.

And I can't take the key out of the ignition. I need to disconnect the battery to do that.

So where did I screw up? By not disconnecting the battery prior starting the removal of the original assembly?

Or the junkyard's ECU needs to be reprogrammed after being swapped into my assembly?

Please help! Thank you all in advance.

 

You've posted the same question in 3 different threads. The shift lock control ecu does not require reset. it's plug and play. The junkyard part may be defect, or you did not install the part correctly.

 

Sorry for overposting, I've been pretty frustrated with all the labor I put in taking apart/putting back together both ECU's and no mechanic around here knows whats up with it. Taking it to the dealer for a scan tomorrow.