Fryall4

Welp, after scouring the interwebs, I can find nothing on my current keyless entry problem.

1997 GMC Sierra extended cab, 4 wheel drive, AT, step-side. Power windows and locks.

My master power window/lock switch was acting strange.. sometimes the window switch would work and sometimes not. I swapped it out with an Amazon special and it worked fine, although, I did notice the illumination on the door lock switch stayed on, when the key was removed. No worries, I have a good battery, I thought.

I drove the truck a couple days later and found the keyless entry was not working properly, where it worked perfectly fine before I had swapped out the window switch.

Pressing lock on the fob, quickly locks and unlocks the drivers side. Pressing and holding the unlock button on the fob will lock the drivers side. Nothing happens with the passenger side in either case. The lock switch on the door operates windows and both door locks as it should.

I figured, bad window switch, so I ordered another switch from a different vender with the same illumination staying on and same keyless entry symptoms. Any ideas on where to go from here?

Gumby22

Start by trying to reprogram the key fob(s). The driver side window switch is also the driver door module and controls remote entry functions.

At the DLC (OBD2 port), Jumper pin 8 (black/white wire) to pin 4 (black wire) or to a good ground. Turn the key on - the doors should lock and unlock within a couple seconds. Once that happens, press and hold both lock and unlock buttons on the key fob simultaneously until the locks activate again. If you have a second fob to program, do the same.

Shut the key off and verify fob programming/operation by pressing each button.

Fryall4

Thanks for the reply!

I just reprogrammed the fobs, and the same thing is happening when they are used.

Light on the lock part of the switch still illuminated without the key turned. A quick lock and unlock of the drivers door when the lock button on the fob is pushed. Drivers door locks when the unlock button on the fob is held down for a few seconds. The passenger side is still unaffected by the fobs and the lock button on the master window switch works the locks properly.

Possessed truck?

Gumby22

Will the passenger lock work if the button on the driver door is used? Try it with both doors open and closed. It could potentially be a short/open in the wiring harness that was fine until you moved the harness around to replace the switch.

Are you certain you got the correct replacement switch for your truck?

Also, apologies for the wrong info earlier - the door lock/window switch is not also the control module for the keyless entry (GM introduced that set up a few years later) - there’s a remote control receiver under the dash that uses a relay to control the locks.

The next step will be to either have the BCM and remote receiver scanned for codes (pro level scan tool needed) or to start checking for signals at the passenger lock actuator when pressing the fob button and trace the circuit back from there.

Fryall4

I ordered the switch twice so far, and both vendors stated that it was proper for my truck. Looked like aftermarket versions of the original switch which it initially replaced.

The door lock button on the drivers door does operate both locks properly.

I will get out there in the morning and test with door open and closed.

Thanks fir the guidance!

Fryall4

Alrighty, messing around a little this morning showed the same symptoms as before whether the doors were opened or closed. But.. I did notice the passenger side lock button on the door gives the same, quick lock and unlocking of the drivers side lock. The passenger side lock on the door is very difficult to manipulate, although the drivers side lock button functions both sides properly.

Bad lock switch on the passenger side? I'll preemptively order one and get it on it's way just in case.

Gumby22

Try lubricating the door latch and linkages with WD40 or equivalent. Manually work the lock and open/close the door several times to work the lubricant into the mechanism. If that doesn’t work, the actuator/latch assembly will need replacement.

Fryall4

No luck with the new passenger side switch, same exact symptoms as before.

Passenger side switch gives a quick lock and then unlock with one push of the Lock button on the keyless fob or push of the Lock button on switch itself.

Symptoms:
The master switch on the drivers side operates all functions properly.

The keyless entry fobs just stopped working properly. Pressing the Lock button gives a quick lock and unlock of both door mechanisms. If the doors are locked and I press the unlock button on the fob, the drivers door unlocks and the passenger side remains locked.

Done so far:
Switched master drivers side door switch twice (both inexpensive Amazon specials), the illumination on both switches stays on with or without the key being in the on position.

Reprogrammed both keyless entry fobs.

Replaced passenger side door switch (Standard Products, mid priced switch).

Tested with doors open and closed, fumbled with wiring between the door and cab (possible wire short in between).

Disconnected battery over night.

Nothing so far has changed a thing. Any other ideas before it goes into the shop?

Little Bear

I have the exact same problem on my 2000 C2500. After seeing what you have gone through I think I'm going to look through my junk pile and see if I can find an OEM switch and try it as I have a replacement in mine that like yours stays lit with the key off.

Fryall4

A good next step I think. I just ordered a Doorman brand master switch. I'll get back to CA on Wednesday and see if the original switch is still in the trash, lol, of course I tossed it. After that I will swap the actuators and then off to my go-to shop to have the wiring traced. Actuators won't solve it I know, master switch operates both sides properly, but I'll do it to rule them out completely.

The truck is in good shape, wiring unmolested and properly loomed up. Possibility. Keyless receiver? BCM? We will see.