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Shift Lock Issue- Need part # & diagnosis help

34K views 14 replies 8 participants last post by  STFU 
#1 ·
Have a 2005 TB, issue is the shifter won't shift out of park. I have read for 2 days all the posts that I can find. This is what I know

Fuse 25 & 27 are good-used a multimeter
tail lights work when I step on brake pedal
key comes out of ignition lock as it should
I can get shifter to move if I use the override switch on side
I can not hear any clicking from the shifter solenoid when I step on the brake pedal with engine running

I have checked for voltage & ground at the a/t shift lock solenoid switch

With car running I have the following votage & continuity readings;
1. light green/black wire & dark green/black wire have battery voltage

2. black wire is grounded (used multimeter to confirm)

3. red wire - can't remember if I had voltage here or not

4. yellow wire - no voltage or ground

Is there any other tests that I can do to confirm that the shift lock control solenoid is the issue? If not, can someone tell me the part # for the shift lock control solenoid? Dealer quoted me $93. Also is there a thread showing the installation of the solenoid? Thanks in advance
 
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#2 ·
You might want to check the brake switch itself. I don't have the
wiring diagram handy, but on my '98 Lumina, the brake switch had
separate contacts for light circuit vs. safety interlock. The switch might
not be closing to activate the solenoid, but just going by the
brake lights might not be a complete diagnostic.

Granted, this doesn't rule out the solenoid failing, but you might
also try putting power to the solenoid and see if it reacts.
Check for that voltage on the red wire. If I had the wiring diag. with
me I might be able to tell you which wire is supposed to carry
voltage when the circuit is activated. It might be that the red
should carry power, and the yellow is the coil trigger?...can't be
sure, but see if you can remember whether you had V or not on that
red. Might tell you what's what.

Did you check Compnine.com for that solenoid? Parts4Chevys.com
or GMpartsdirect might have some options for you as well.

Good Luck!

Chris
 
#5 ·
Fixed

I checked the brake switch & it was fine. Issue was the shift lock solenoid. I had power going to it, but it wouldn't energize. Due to tight funds, I simply removed the solenoid (comes out with 2 small torx bolts), but left the electrical plug connected. That way the ignition key will release.


Now I can move the shifter w/o pushing brake pedal. Thats' not an issue for me, that used to be the way all a/t functioned.

Anyway, if someone else has the same issue in the future, this is a way around not spending $100 for a new switch.
 
#6 ·
Glad you were able to get around the failed part. Is the solenoid coil
shot, or just a jammed plunger? Just wondering if you could resurrect it,
though since you've bypassed it, obviously not an issue... :)

Either way, glad you were able to get yourself out of park!

Cheers-

Chris
 
#7 ·
Please take a pic of this solenoid next time you are down there. This would be handy to know.

On my prior vehicle I intentionally disabled the shift interlock to provide a one second advantage against zombie attack. It was a column shift and was all good. My Trailblazer on the otherhand, I would be afraid to do it because I might accidentally shift it out of gear if I crawled from one seat to another.

Still would be cool to know where the part is in case one day it failed. a workaround could be done on the spot.
 
#13 ·
I love this site

Thanks Roadie, your info was spot on. Unfortunately it fixed my initial problem. lol Now I've discovered more. I'm going to break it down to see what you think.

Left work on Monday, got in truck and drove to the front door. Got out to get something inside, came back out and truck would not shift. After searching on this site I learned about the Shift lock Selonoid plunger. Got the truck going and went to pick up my son. Turned off the truck and cylinder would not rotate all the way back, key stuck in ignition now. Ordered Shift Lock Selonoid but have not received it yet. Removed center console and discovered broken wires leading the the electrical connector to the seloloid. Purchased new connector, could not figure out color sequence ( Roadie provided answer). Start truck this morning and trans feels like its slipping in drive, have to rev engine to get it going, once going seems fine. Took it to a trans mechanic, hooked it up and all sort of selonoids are flashing error codes, mechanic says it's not a bad tranny. Got home and connected correctly the new wires for bad selonoid. Truck now shifts fine but key is still stuck and still slipping in drive. HELP.:x
 
#15 ·
I found that if you unplug the connector, then the key will not turn all the way back and come out.
I removed the solenoid, (plunger was not stuck) plugged the connector back into the bad solenoid, and just left it in the space under the console.
Why was that even a thing anyway?
I guess they were trying to idiot proof it. :ROFLMAO:
I actually prefer not having to hold down the brake to shift out of park.
I may take that solenoid out of all of my vehicles :cool:
 
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