DTC code B2723
Thread Starter
Instructor
Joined: Sep 2001
Posts: 222
Likes: 1
From: ann arbor michigan
DTC code B2723
Theft Deterrent System code B2723 has shut down my 2004 C-5. By luck this happened in my garage. Looking at the GM service manual I require either a scan tool (don't have) or will be forced to have the car towed to a GM dealer (really don't want to do this). Has anyone had this problem and is there a way that I can fix it? I tried three separate keys to see if the electronic plug in the key was the problem. All three keys had been used recently and all three keys couldn't get the car to start. Any help would be greatly appreciated as this is the only car I have to drive to work. Thanks in advance.
Tech Contributor
Joined: Jan 2007
Posts: 19,116
Likes: 1,038
From: Dyer, IN
I disagree. He has a code for the pass key detection circuit. If the BCM was getting the correct resistance from the key, the TDR would work. Possibilities are a lock cylinder, wiring, or BCM for this code(considering he has tried multiple keys)..........not the TDR
Instructor
Joined: Jul 2004
Posts: 108
Likes: 0
From: North Wales PA
I just had a similar problem and your suggestion and caution regarding jumping the red and purple and having the manual trans in neutral was accurate. I jumpered the red and purple, the car cranked and I replaced the thrift deterrent relay and voila,...back cruising again!
Melting Slicks
Joined: Dec 2018
Posts: 2,606
Likes: 1,359
From: Orange County, CA
Three cheers! It worked for me! Many thanks!! I just had a similar problem and your suggestion and caution regarding jumping the red and purple and having the manual trans in neutral was accurate. I jumpered the red and purple, the car cranked and I replaced the thrift deterrent relay and voila,...back cruising again!
I just had a similar problem and your suggestion and caution regarding jumping the red and purple and having the manual trans in neutral was accurate. I jumpered the red and purple, the car cranked and I replaced the thrift deterrent relay and voila,...back cruising again!I was in the midst of errands, when randomly my Z06 wouldn't start (sitting in a Boston Market parking lot, of all places). Starter didn't even try to spin. Battery voltage looked fine. It listed code B2723 CH, which brought me to this thread.
Pulled open the passenger foot compartment, jumpered red and purple while the key was ON (trans in neutral), and it started right up and got me home.
I'll be ordering a replacement relay and ignition switch (for good measure).
Melting Slicks
Joined: Dec 2018
Posts: 2,606
Likes: 1,359
From: Orange County, CA
When/while red and purple are jumped, the starter spins. You only have red and purple "connected" long enough for the engine to start.
Melting Slicks
Joined: Dec 2018
Posts: 2,606
Likes: 1,359
From: Orange County, CA
Just to close the loop... I replaced:
- Ignition switch, , which came in a 'Genuine GM' box.
- Theft Deterrent Relay,
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2nd Gear
Joined: Apr 2022
Posts: 2
Likes: 1
Help with DTC code B2723
Hello I have a 99 automatic that I has a code b2723 as well. The car was taken on trade started and ran until I replaced the battery, and this code is all that's showing. I went ahead and tried to by pass / jump the starter. It's cranked starts for a split second and cuts off like it's getting no fuel . I noticed all these were manuals mines and automatic. Is there anything I need to do while starting it ? Foot on brake? Key on I assume? Also is the fix replacing the td relay? Or is something else going on. I was told the car had vats removed? I'm guessing this code and no start suggest otherwise. Any help would be appreciated thanks!
Last edited by oldmanonlyfan; Apr 24, 2022 at 10:31 AM.
2nd Gear
Joined: Apr 2022
Posts: 2
Likes: 1
Help with DTC code B2723
Hello I have a 99 automatic that has a code b2723 as well. The car was taken on trade started and ran until I replaced the battery, and this code is all that's showing. I went ahead and tried to by pass / jump the starter. It's cranked starts for a split second and cuts off like it's getting no fuel . I noticed all the one on this post were manual started in neutral. mine is an automatic. Is there anything I need to do while starting it ? Foot on brake? Key on I assume? DO I need to clear code before jumping? Also is the ACTUAL fix replacing the relay? Or is something else going on. I was told the car had vats removed turned off by a locksmith, i actually paid for this service. I'm guessing this code and no start suggest otherwise? I don't see a vats module/catagor on my scan tool not sure if i would , or if he did remove it or turn it off.Any help would be appreciated thanks
Last edited by oldmanonlyfan; Apr 24, 2022 at 10:27 AM.
1st Gear
Joined: Nov 2022
Posts: 1
Likes: 0
Ignition
Did you have to change the key after changing the ignition?
Just to close the loop... I replaced:
- Ignition switch, ACDelco D1499C on Amazon, which came in a 'Genuine GM' box.
- Theft Deterrent Relay, Standard Motor Products Relay RY282
Melting Slicks
Joined: Dec 2018
Posts: 2,606
Likes: 1,359
From: Orange County, CA
No, there are 2 parts to the ignition: 1) lock cylinder, that the key goes into; 2) ignition switch, which is allowed to turn when the lock cylinder unlocks it. Replacing the ignition switch doesn't impact the lock cylinder, so you can continue using your existing key.
