View Full Version : HELP!2006 STS will not crank after engine replacement.Trying to relearn theft.P01631

03-26-11, 07:28 PM
I have a 2006 STS that we acquired cheaply and had to put a new engine in immediately, it cranked and had no compression and the new engine was cheaper than new valves. Everything went good and now it will only clack the starter and it says theft problem on the info center. Getting code P01631, I cannot get the fob to even get the starter to clack, everything else works on the key fob, lock, unlock, trunk and it is fob #1. I see the procedure much like the older gm stuff where you turn on the ignition, try to start and leave in the run position for 10 minutes or so until the theft light goes out. If I turn on the ignition with the push button, it says to push brake and hit button, which I do then it will clack the starter and do nothing until several seconds later it will run a gauge test, then a minute or so later it kind of turn everything on like the lights and is like the ignition is on. How do you relearn the theft without the keyhole in the dash?
I did try the valet switch in the glove box and was able to relearn another fob, but still stuck in theft. Talked to a GM Tech friend of mine and he thinks we have to reprogram the system on Monday.

03-27-11, 12:28 AM
Relearning fobs is a different process and what you describe is not surprising. I'm guessing you replaced the ECM with one you received with the new engine. There is a password that must be synchronized between the theft deterrent system (in the case of the STS, the RCDLR handles this function) and the ECM. When you replace the ECM, these passwords will no longer match and the car won't start. It will require reprogramming of the theft deterrent system. I recently reprogrammed an SRX because the ECM had to be replaced. Basically the same procedure.

DTC P1631 Theft Deterrent Start Enable Signal Not Correct

"The remote control door lock receiver (RCDLR) sends the fuel enable password to the engine control module (ECM) via the serial data circuit. The ECM verifies the fuel enable password received matches the password stored in memory. If the fuel continue password is correct, the ECM enables the starting and fuel delivery systems. When replacing a ECM with a GM SPO replacement part, the new ECM will learn the incoming fuel enable password immediately upon request."

You can do this on your own, IF you don't have a vehicle configured for export out of the US:

Important: This procedure is not available on vehicles equipped with EXPORT configured modules.

1. Press and hold the OFF/Acc button for approximately 4 seconds to turn the ignition ON, with the engine OFF.
2. Observe the Security indicator. After approximately 10 minutes the indicator will turn off.
3. Turn OFF the ignition, and wait 5 seconds.
4. Repeat steps 1-3 two more times for a total of 3 cycles or 30 minutes.

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

Start the vehicle. The module being programmed has now learned the RCDLR password.
With a scan tool, clear any DTCs.

03-28-11, 10:29 AM
That seems close, but with the right twist I hope. Going to give it a try otherwise my friend at GM is going to give it a shot later today.

03-28-11, 10:55 AM
That seems close, but with the right twist I hope. Going to give it a try otherwise my friend at GM is going to give it a shot later today.
As long as it isn't an export configured vehicle, it should work. This is the process directly from the 2006 STS service manual. Post back and let us know.