codes 2721 and 2723 security light on
Thread Starter
Safety Car
Joined: Oct 2004
Posts: 4,816
Likes: 132
From: Plano TX
tried another key and it started 1 time and then it would not start again with either key.. I'm thinking the battery? With the key in the on position I'm showing 11.0 amps
Last edited by David426; Sep 5, 2010 at 12:08 AM.
Thread Starter
Safety Car
Joined: Oct 2004
Posts: 4,816
Likes: 132
From: Plano TX
Sprayed cleaner into ignition switch and inserted the key about 12 times to make sure the key reader was clean... also cleaned the key pellet.. Cleared codes... So far all is well..
Le Mans Master
Joined: Oct 2000
Posts: 6,362
Likes: 30
From: Oak Harbor WA
If it is like my car, the issue will return. I hope I am wrong. There are many reasons it can be set. Cleaning is the first and easiest fix for this. Bill Curlee did a writeup on how to clean the ignition switch but if you are getting codes about the PASS-Key system then the switch isn't the issue per se, the reader portion of the switch is or something else within the circuit itself (grounds, TDR, BCM, PCM etc).
Thread Starter
Safety Car
Joined: Oct 2004
Posts: 4,816
Likes: 132
From: Plano TX
If it is like my car, the issue will return. I hope I am wrong. There are many reasons it can be set. Cleaning is the first and easiest fix for this. Bill Curlee did a writeup on how to clean the ignition switch but if you are getting codes about the PASS-Key system then the switch isn't the issue per se, the reader portion of the switch is or something else within the circuit itself (grounds, TDR, BCM, PCM etc).
Le Mans Master
Joined: Oct 2000
Posts: 6,362
Likes: 30
From: Oak Harbor WA
I have a thread in this section right now asking for more help to confirm what is wrong with my car. I'll admit it now, I am terrible with electrical schematics. Sure I can trace a wire okay, one color on another just fine, but knowing the amps, volts or ohms for a specific circuit is a bit beyond my knowledge these days.
My issue is best described as the "try to start the car and have to wait 3 minutes syndrome".
DTC B2721 - The BCM supplied a 5 volt signal and a ground circuit for the PASS-Key system. An invalid resistance amount results in a code.
From my 2001 manual: if the key resistor pellet is incorrect, there will be no BCM outputs to the TDR or to the PCM. This state will last about 3 minutes.
Trying to start the car will reset the clock. Disconnecting the battery will reset the clock. If a good key is inserted the car will not start until after the 3 mins has elapsed.
No resolution yet but I have two new parts on order right now: new switch and new lock cylinder. The lock cylinder has the new key reader in it.
My issue is best described as the "try to start the car and have to wait 3 minutes syndrome".
DTC B2721 - The BCM supplied a 5 volt signal and a ground circuit for the PASS-Key system. An invalid resistance amount results in a code.
From my 2001 manual: if the key resistor pellet is incorrect, there will be no BCM outputs to the TDR or to the PCM. This state will last about 3 minutes.
Trying to start the car will reset the clock. Disconnecting the battery will reset the clock. If a good key is inserted the car will not start until after the 3 mins has elapsed.
No resolution yet but I have two new parts on order right now: new switch and new lock cylinder. The lock cylinder has the new key reader in it.
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