NEED HELP Shift indicator lights and such

[crazyelvis3577]

I just put new connectors on my 2003 Envoy XL that connect to the neutral safety switch or the NSBU. This was after my shifter wouldn't shift from park and I was trying to get it to move out of park by giggling the shifter pretty hard then it locked up again and I slammed the shifter back and forth needless to say it broke the shaft in the shifter but it will still allow me to shift gears (I disconnected the lock solenoid) So after doing all of this and then putting new connectors on the NSBU switch sonetimes the indicator lights (line under the gears) all work and then I can drive it and then shut it off and then every other one will work. What could be causing this? I have double check the wiring on the bew connectors. Could the NSBU be knocked out of adjustment or loose enough to move from time to time or maybe damaged insides from slamming the shifter back and forth? I cab still drive it and the engine and tranny all operate correctly. Anybody else have this happen? I've also heard that it can sonetimes be the ignition switch. Any help is appreciated!!

 

[Mooseman]

Doesn't sound like an ignition switch problem since there aren't any other electrical issues. I'd investigate further into the switch and connector. I don't remember if the PRNDL is actuated at the shifter or inside the tranny.

 

[crazyelvis3577]

All of the gears shift fine and my backup lights work. Just some of of the indicators (little line under the PRND321) don't work at times. Other times all of the indicators work. I'm thinking it could possibly be inside the NSBU switch where I slammed it and maybe broke something internally. Could be out of adjustment or loose I haven't really investigated it yet, but I did double check the wiring where I put new connectors on and it seems good. But for the indicators to work like they are it seems logical that something could be broken inside the NSBU switch.

 

[crazyelvis3577]

I was just thinking and would it be possible for this NSBU switch to get moisture inside causing the problem?.. after all I did have the transmission disconnected a few weeks ago to put a "new" engine in. So maybe it could have gotten cracked in the process... just a thought

 

[crazyelvis3577]

Anybody have anymore thoughts on what it could possible be? The shift indicators that don't work all the time are PN31. After a while they seem to work though after the vehicle has say "warmed up." RD2 work all the time. Could this be a wiring issue (which I don't think it is)? Or could it be bigger problems? My thought is maybe the neutral safety switch on the tranny is either cracked allowing moisture inside, out of adjustment, or broken contacts inside the neutral safety switch that are sticking and then releasing at times as the shifter is moved back and forth. Just trying to get possible causes before I dig into it. Everything else works just fine.

 

[Mooseman]

One possibility, albeit a slim one, is that those segments in the cluster are flaky. If you can find somebody with a Tech 2, this could be checked. This could also verify that the PCM is correctly receiving what gear is selected.

 

[crazyelvis3577]

If that were the problem wouldn't it affect the whole cluster as far a gear indicators go?

 

[crazyelvis3577]

After all those segments are connected to the same section in the cluster. so could it actually be a pcm problem since the pcm gets the gear selected from neutral safety switch on the side of the tranny. I'm planning on putting a new neutral safety switch on first or checking to make sure the current one is in correct aligment to display correct gear. Would a switch that's out of alignment show any of the gears correctly?..

 

[mrrsm]

If you Altered, Broke or Bypassed/Defeated any Mechanical or Electrical portion of this Park Lock Circuitry Diagram shown in the PDF listed below and the vehicle is now capable of being started while in ANY gear position, then you should repair this problem back to the OEM Safe Condition First ...BEFORE investigating or changing out the The Park Neutral Safety Switch (PNSS) on the Transmission as the source of the problem.

If you destroyed the Shift Lock Solenoid located in the underside of the Center Console...it will have to be replaced. @MAY03LT has this video to help you disassemble the area enough to gain access to the components and replace what is ordinarily obscured from easy access and view. And even though his reasons doing the R&R relate to different issues from your own ...watch closely for the imagery that shows the location of the Broken/Damaged Lock Solenoid and how to get the Broken A/T Shift Lock Actuator Solenoid Out...and a New One back In:

Click on the "YOUTUBE" Icon at the Lower RH Side to go to Youtube to view this video:

In general, if the Fastener holding on the PNSS has been tightened down hard enough to mushroom the end of the 4L60E Shift Position Armature underneath it… if you don’t remove that burred expansion with a file before installing a brand new Park Neutral Safety… the Internal Rotating Plastic Piece on the inside of the PNSS will be damaged as you try to force it over the Mushroomed End into position.

It may also be necessary to use Needle Nose Pliers to carefully and completely destroy the Two Connection Points where the Electrical Harness Plugs attach inside of the body of the PNSS to get them loose from the Factory applied "Gorilla Glue" that holds the plugs in place. And so great care must be observed so as not to ruin either the Two Harness Plugs... or their Wiring. It is unclear which year your Envoy is...so this is the Best Available PDF on the subject:

“The following schematic describes the 2003 GMC Envoy XL Shift Interlock System Wiring and Circuit Diagram. The shift interlock system is designed to prevent the automatic transmission from being shifted out of PARK to any range unless the brake pedal is depressed. GMC Envoy XL Shift Interlock System consists of fuse (under-hood fuse block), park/neutral position switch, stop lamp switch, A/T shift lock actuator.”

http//www.justanswer.com/uploads/JHoop/2008-03-03_131052_shift_solenoid.pdf

 

[crazyelvis3577]

That's a good schematic. Would it still show what gear it's in with a bad fuse? Probably not but checking fuses is my first move. I thought it could be a relay instead of a fuse causing the gear indicators to only work part of the time. It's obly certain gears that it does that with it always shows rd2 but the others only show sometimes. If the car runs for awhile they seem to work. Brakelights and backup lights work and I can hear the interlock solenoid working even though it's not mounted on the shifter at the moment. That's why I thought maybe a bas NSS

 

[mrrsm]

Here is the salient Safety Issue... Even though the Electrical Circuit between the Brake Pedal and the A/T Lock Actuator still responds when you Step on the Brake... the point is moot... The Purpose of the Brake to Shifter relationship is to simply to ensure that a Driver is actually seated in the Driver's Seat before "Releasing the Locking Pin" that restrains the movement of the Shifter Lever.

But in your situation... with the PIN portion of the Solenoid Device being Snapped Off... anybody could reach in and move the Shifter out of Park and into Neutral and either watch the damned SUV roll down a hill ...or by turning the key when reaching over the Steering Column... start it up the Engine in Neutral and then God Knows What Might Happen After THAT if it gets thrown into Gear.

First things First... Fix the Safety Issue by replacing The One Component in the Circuitry that you KNOW is FUBARed ...and eliminate any further sketchy behavior the Shift Lock Solenoid might be doing in between...and THEN if needs be... you can sort out the PNSS issues.

 

[Dbinder]

I just put new connectors on my 2003 Envoy XL that connect to the neutral safety switch or the NSBU. This was after my shifter wouldn't shift from park and I was trying to get it to move out of park by giggling the shifter pretty hard then it locked up again and I slammed the shifter back and forth needless to say it broke the shaft in the shifter but it will still allow me to shift gears (I disconnected the lock solenoid) So after doing all of this and then putting new connectors on the NSBU switch sonetimes the indicator lights (line under the gears) all work and then I can drive it and then shut it off and then every other one will work. What could be causing this? I have double check the wiring on the bew connectors. Could the NSBU be knocked out of adjustment or loose enough to move from time to time or maybe damaged insides from slamming the shifter back and forth? I cab still drive it and the engine and tranny all operate correctly. Anybody else have this happen? I've also heard that it can sonetimes be the ignition switch. Any help is appreciated!!

Check the ground connection G201 it can be the root of many problems like shifter or key getting stuck in ignition and many other electrical gremlins. See MAY03LTs you tube video

 

[crazyelvis3577]

I haven't checked that. Weird thing today I go out start the truck and the shift indicators aren't working on PN31 but the others indicators are working just like before. I press the brake pedal a few times and hear the shift interlock solenoid click and when I look up all the gear indicators are working. I also hear the click in the column where the key goes. Leads me to believe that my neutral safety switch is fine. Could it be brake switch even though my brake lights work? Or is it probably the interlock solenoid or connector?... I haven't checked the fuses but it seems they are fine since everything else works. I'm thinking it could possible be the interlock solenoid causing the whole problem. Any thoughts on this??

 

[mrrsm]

If during the R&R of the Transmission, you removed the Two Electrical Connection Plugs from their seats inside the Park-Neutral-Safety-Switch where they were originally "Gorilla Glued" at The Factory during assembly ...and pulled on them too hard… then you might have damaged either the wiring connections inside of one or both of the plugs or ...wound up “stranding” the Copper Wire(s) of one or many wires by stretching the harness enough to break them inside of the “stretchy” insulation and not reveal the problem.

The best way to Test the continuity of the Two Plugs and their stability would be to presently leave the OEM PNSS in place… and unplug the two connectors from the OLD PNNS and insert them into a Brand New PNSS. Then with the Ignition Keyed to the On position (NOT with the Engine Running and with the Shifter handle placed in the PARK Position) ...use a Wood Dowel to rotate the center Grommet inside the PNSS and observe each of the Dash Panel lights to see if the electrical connections are sound. If the lights on the Dash still misbehave… then you know to investigate the various wires in the Wire Harness and Plugs for continuity.

If the lights are all good, Swap in the Brand New PNSS, insert the Two Plugs and seal them around the outside with Permatex RTV and some Zip-Ties to secure them Weather-Proof and snug and after replacing the A/T Shift Lock Actuator Solenoid… you should be “Good To Go.” The attached images demonstrate how difficult it is to extract these Two Harness Plugs due to the presence of the “OEM Gorilla Glue” and hence the need to destroy the PNSS itself rather than risk damaging the Two Plugs and the Harness Wires.

 

[crazyelvis3577]

Ok I have put a new shifter and interlock solenoid in anc checked the wiring for breaks and such and all looks good. The gear indicator lights worked just fine yesterday after replcing the shifter and solenoid. Worked time after time. Went out today and it did the same thing as before. Went to eat and then when I got back in the car and turned the switch the indicator lights worked again. Does this sound like it could possibly be a ignition switch problem?.. It's got me stumped for sure.

 

[crazyelvis3577]

Still trying to figure this problem out. Anybody maybe new members got any idea what’s causing this?...

 

[Mooseman]

One possibility, albeit a slim one, is that those segments in the cluster are flaky. If you can find somebody with a Tech 2, this could be checked. This could also verify that the PCM is correctly receiving what gear is selected.

Have you looked at this possibility? IIRC, those are individual LEDs. Instead of finding a Tech 2 to test it out (at a dealer for $$$), if you can get one from a junker at a pick-n-pull and swap it out. It could be a bad common trace or solder joint on the board.

I've looked at GM-SI and the PDF manuals and I can't find schematic info on those LEDs in the cluster but as far as I can tell, the position switch on the tranny sends a signal to the PCM and sends the info to the cluster controller (possibly through the BCM) via the databus to light the proper LED.

 

[Sparky]

Does the 2003 use LEDs under printed letters, or use an LCD for the gear indicator? My 2002 had the blue LCD-style indicator. I don't know when they switched to the LED setup (which was cheaper I'm sure but also uglier IMO, I liked my LCD readout).

My guess is if it all worked normally until the slamming incident it has to do with that. If when it acts up you slowly move the shifter or wiggle it in its place, does the line that isn't working ever light up again or flicker?