‘97 BCM handshake/no start issues
Thread Starter
Cruising
Joined: Apr 2025
Posts: 10
Likes: 0
‘97 BCM handshake/no start issues
Hey all,
Ive been having no start issues for the past few months and am all out of ideas. For a while, I would just jump the TDR to start and that was fine for the time being. I’ve been battling a few other electrical issues as well and ended up buying a new bcm which fixed all my issues other than no start from key. I made sure the numbers matched up and all that. Installation was simple enough but I’m having problems regarding the handshake between the BCM and ignition. For some reason, the security light is not coming on for me to do the handshake, it still shows code B2723, and the car still will not crank when key is turned. However, it will still start and drive when the TDR relay is jumped, and I did verify I get 12v from the yellow wire in the TDR relay. I ran a ground wire from the frame to the black/yellow wire in the TDR and still nothing. Any advice would be appreciated.
Edit: I’ve replaced the relay as well and had no luck with that either
Ive been having no start issues for the past few months and am all out of ideas. For a while, I would just jump the TDR to start and that was fine for the time being. I’ve been battling a few other electrical issues as well and ended up buying a new bcm which fixed all my issues other than no start from key. I made sure the numbers matched up and all that. Installation was simple enough but I’m having problems regarding the handshake between the BCM and ignition. For some reason, the security light is not coming on for me to do the handshake, it still shows code B2723, and the car still will not crank when key is turned. However, it will still start and drive when the TDR relay is jumped, and I did verify I get 12v from the yellow wire in the TDR relay. I ran a ground wire from the frame to the black/yellow wire in the TDR and still nothing. Any advice would be appreciated.
Edit: I’ve replaced the relay as well and had no luck with that either
Melting Slicks
Joined: Sep 2008
Posts: 3,127
Likes: 799
From: Espanola New Mexico
Simple question, can you hear the TDR click on when you turn the key to the start position of the Ignition switch? If you have 12v on yellow and a good ground on the yellow black stripped wire there's no reason the TDR should not energize unless you have bad connection at the TDR socket.
Melting Slicks
Joined: Sep 2008
Posts: 3,127
Likes: 799
From: Espanola New Mexico
You also have to do a relearn procedure when you replace the BCM, it's not plug and play. Three 11 minute with key on and 30 secound off periods between the 11 minute on times, do a search to make sure.
Thread Starter
Cruising
Joined: Apr 2025
Posts: 10
Likes: 0
I do not hear the relay energize when the key is in the start position. I could have a bad connection so i’ll check that out. Regarding the relearn, I did read about that on these forums and in my service manual. The only issue is that the security light is supposed to come on when the bcm doesn’t recognize the key, but when I put my key in the security light doesn’t come on so I’m unable to do the relearn. I had another ignition switch laying around so I thought maybe it was an ignition switch issue but still no security light. This was happening before and after the bcm swap so maybe a wiring/connection issue of some kind?
Thread Starter
Cruising
Joined: Apr 2025
Posts: 10
Likes: 0
I must be misunderstanding the process. The instructions from the service manual are as follows:30 Minute Learn Procedure
You must turn the ignition OFF before attempting to start the vehicle.
It says to observe the security telltale, but after following the steps up to #3, there is no security indication to confirm the process is started.
- Turn ON the ignition, with the engine OFF.
- Attempt to start the engine, then release the key to ON (vehicle will not start).
- Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.
- Turn OFF the ignition, and wait 5 seconds.
- Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes (the vehicle is now ready to relearn the password on the next ignition switch transition from OFF to CRANK).
You must turn the ignition OFF before attempting to start the vehicle.
- Start the engine (the vehicle has now learned the password).
- With a scan tool, clear any DTCs if needed (history DTCs will self clear after 100 ignition cycles)
It says to observe the security telltale, but after following the steps up to #3, there is no security indication to confirm the process is started.
Melting Slicks
Joined: Sep 2008
Posts: 3,127
Likes: 799
From: Espanola New Mexico
Maybe the Security light bulb is bad, or bad connection somewhere? Still very puzzling to me how you can have 12v on the yellow wire and a good ground on the yellow black stripped wire and the TDR will not energize, something is amiss, suggest putting a meter across the TDR coil wires and confirming you have 12v. Have you replaced the TDR?
Thread Starter
Cruising
Joined: Apr 2025
Posts: 10
Likes: 0
Ended up finding a fix. Turns out I had a loose connection on the yellow wire pin going into the female side of the TDR. I still have the ground wire from the frame going to yellow/black wire for it to work but i’m okay with that. I appreciate the responses and help!
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