P1631 Security code?
 

local garage installed new battery. Lack of battery power (from the old one) either reset or set-off the security mechanism. They were unable to reset it with the usual methods in the user's manual. They said they kept getting a P1631 code. Did they get that from their computer? I neglected to ask at the time, but I assumed.
local garage suggested that it might be the security feature not recognizing the chip in my key.

...my key has a chip in it?

any similar experiences? successful fixes? I'm likely getting it towed to the dealership tomorrow.

year/ model?

2001 SL (silver in color, 4 doors, 4 wheels, Spongebob air-freshner etc.)

check air freshener for intermittent short at ignition cylinder


I do believe your key has a chip.

P1631 appears to be "Theft deterrent start enable signal not correct"

The test checks for mismatched passwords between the the PCM and the BCM

There is an interesting procedure requiring intervals of 11 min and 30 seconds regarding a relearning of the password I think

Would you like me to post it?

for thoroughness

When the Passlock portion of the VTD system has sensed the proper operation of the ignition switch and lock, or determined that the switch and lock have not been tampered with, the BCM transmits a password to the PCM. Fuel delivery is enabled if this password matches the password stored in the modules memory. If a component in the theft deterrent system has been replaced, the modules need to relearn the password of the new components. If the relearn procedure was not performed, this DTC will set.

If a VTD failure occurs during an ignition cycle that the PCM has enabled fuel, then the BCM will enter a fail-safe mode: Fail Enable VTD System Failure with Fuel Enabled. The BCM remains in Fail Enable Mode, for the current and future ignition cycles, until the fault is corrected and a valid password is received, or until battery power is removed. If the battery is disconnected or the codes are cleared, the vehicle will lose its Fail Enable status and will not start until the fault is corrected, the 10-minute timer expires, and the PCM receives the correct fuel delivery password.

ok

Multiple answers but all for GM vehicles with Passlock Security

I vouch for none of them

#1_____________
PROCEDURE:

Insert key, attempt to start the vehicle and leave the key in the ON position.
In some vehicles, the Battery and Security light will blink for several seconds, and then shut off. Then the Security light will then remain ON. Leave the ignition ON until the Security light goes OFF. This will take more than 5 mins.
When the Security light goes OFF, turn the ignition to the OFF position.
Leave ignition OFF for 20 Seconds.
Attempt to start the vehicle again and leave the key in the ON position.
In some vehicles, the Battery and Security light will blink for several seconds, and then shut off. Then the Security light will then remain ON. Leave the ignition ON until the Security light goes OFF. This will take more than 5 mins.
Turn the ignition to the OFF position for 20 Seconds.
Attempt to start the vehicle again and leave the key in the ON position.
In some vehicles, the Battery and Security light will blink for several seconds, and then shut off. Then the Security light will then remain ON. Leave the ignition ON until the Security light goes OFF. This will take more than 5 mins.
Once this entire procedure has been completed (three times) your vehicle will start on the fourth attempt.
Note: Some vehicles perform the relearn in a different sequence. You may notice your security light, battery light and abs light will alternate. Once the security light is left out of the sequence that is considered one step. Repeat the procedure two more times and on the fourth time your vehicle will start.


#2____________
Try the following 30 minute re-learn procedure ....

1) Turn ON the ignition with the engine OFF

2) Attempt to start the engine, then release the key to ON (vehicle will not start)

3) Observe the SECURITY warning lamp, after approximately 10 minutes it will turn OFF

4) Turn OFF the ignition, and wait 5 seconds

5) Repeat steps 1 through 4two 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).

IMPORTANT: The vehicle learns the password on the next ignition transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.

6) Start the engine (the vehicle has now learned the password)

3____________
Step 3 in the link

http://ww2.justanswer.com/uploads/mc...1631-Debug.pdf

Enjoy and don't kill your battery

awww now you logged off...after all my effort

let us know how it goes

I must admit Derf, you were quite thorough in your explaination. Hopefully, those in need of it will commit the data to a file for use later .............

WOW!
I am impressed!
and terrified.

JayBab will now have more time to drink black coffee up in Canadah