Keyless entry not working

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94ChevyZ71

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I recently bought a 99 K1500 suburban and I’ve been trying to work out some of the door lock issues. I’ve replaced most of the door lock actuators along with the door lock switches on driver and passenger side. Everything locks and unlocks fine when using the driver side but when I try the passenger side only the driver side lock will lock then immediately unlock. This suburban is equipped with factory keyless entry. When I use the remote it only locks then immediately unlocks the driver door. If I lock it does the same thing but hitting it 2 times the horn beeps but the doors don’t lock. I replaced the Door lock relay and everything worked perfectly fine for a day and then it went back to what it was doing before. I’m assuming something has killed the new door lock relay. I’ve checked all fuses and they were good. Are they any specific grounds for the keyless entry that I could check? Possibly a bad receiver for the key fob? I pulled the door lock relay and would hit the lock button and could hear another relay clicking under the dash but I haven’t been able to find where it was coming from. Everything else works on the truck. Maybe someone on here could help me out because I’m at a loss. Thanks!!
 

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Orpedcrow

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Are you locking it with the doors open? I don’t know how our trucks keyless entry works but a lot vehicles won’t let you lock the keys in the truck so if it sees the door open it might think the key is inside?
 

94ChevyZ71

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Are you locking it with the doors open? I don’t know how our trucks keyless entry works but a lot vehicles won’t let you lock the keys in the truck so if it sees the door open it might think the key is inside?
I’ve tried it with the doors opened and closed with no dice. I replaced the door lock relay and everything started working properly for a day and now it’s doing the weird only lock then unlock the driver door thing. I checked the plug to the door lock relay and it had 13 volts to the plug. I then tried to reprogram my key fob. All of the door locks cycled when I did that which would imply that my keyless entry receiver is working (I think). So that leaves me to believe that either I just got a bad door lock relay that lasted a day or I have a grounding/wiring issue of some sort. I’ve replaced both door lock switches so I don’t think that’s my issue. When I take the door lock relay out and try to lock the doors I can hear the relay in the keyless receiver click so I assume it’s working. I know without the door lock relay in nothing works but I just did that to check. I’m going to get another door lock relay and give it a try.
 

east302

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Does the cargo area lock switch also not work? If you manually lock the doors does the passenger switch unlock them?

Here are the diagrams for a 98, maybe it will help. It looks like the passenger side uses the relay for power and ground at the actuators, but I’m not too clear on the flow path for the driver switch.

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94ChevyZ71

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Does the cargo area lock switch also not work? If you manually lock the doors does the passenger switch unlock them?

Here are the diagrams for a 98, maybe it will help. It looks like the passenger side uses the relay for power and ground at the actuators, but I’m not too clear on the flow path for the driver switch.

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The cargo lock switch only operates the driver door lock and it locks then immediately unlocks it. When I replaced the door lock relay everything worked for a short time and something has caused it to stop again. I’ve replaced both door lock switches on the driver and passenger side. Even the key fob only locks then unlocks the driver door only.
 

GoToGuy

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First, don't guess. Do not change parts randomly. Your problem is not the door lock relay. It is most likely the door lock control module. Which is the brains of the outfit. On 4x4 trucks it is usually above right knee to right of, near steering column. If you touch it while cycling remote you will feel action in it. The other position, some two wheel drive it is mounted is behind left kick panel. The actions are different whether you have Std cab, Crew Cab, Tahoe, or Suburban. The remote reciever is under dash center, up near windshield.
Currently I had to remove "Courtesy fuse ", which controls power mirrors and dome light. As it lost it's sparky mind and started a " ping pong effect". Dome interior lights would flash on the click off, then click flash on, then click flash off. Back and forth, " ping pong effect". And you could feel and hear the relays in the control module. So removing the fuse just removed power to the interior and dome light. For me the only driver, it on the repair list just not a high priority.
 

94ChevyZ71

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First, don't guess. Do not change parts randomly. Your problem is not the door lock relay. It is most likely the door lock control module. Which is the brains of the outfit. On 4x4 trucks it is usually above right knee to right of, near steering column. If you touch it while cycling remote you will feel action in it. The other position, some two wheel drive it is mounted is behind left kick panel. The actions are different whether you have Std cab, Crew Cab, Tahoe, or Suburban. The remote reciever is under dash center, up near windshield.
Currently I had to remove "Courtesy fuse ", which controls power mirrors and dome light. As it lost it's sparky mind and started a " ping pong effect". Dome interior lights would flash on the click off, then click flash on, then click flash off. Back and forth, " ping pong effect". And you could feel and hear the relays in the control module. So removing the fuse just removed power to the interior and dome light. For me the only driver, it on the repair list just not a high priority.
I just recently bought this suburban and I’ve been trying to get everything in working order. The door lock switches were worn on both sides so I just figured I would go ahead and get new ones. Now is the door lock control module also the keyless entry receiver or are those 2 different things? I know the box you’re describing does click when I lock/unlock the doors. It looks like a pain to get out me swap also. I have checked all my fuses and even put a new one in for the CTSY. I’m hoping whatever box that’s under the dash is the fix for my situation because it bugs the crap out of me.
 
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