This 2000 Cadillac Deville came in with the complaint that the anti theft system lights and messages were on but the vehicle always cranked up just fine. Of course when the vehicle was dropped off at my shop all of the lights were out and everything was normal.
I did a code check and found the history codes B1009 for an EEPROM checksum error, B2734 for coded key controller memory failure and B3055 for a key not being detected. The diagnosis is pretty straight forward for the code B1009. According to GM SI it is an internal fault of the anti theft or PK3 module.
I installed the new part and expected to have the key learned automatically by the new PK3 module. Worst case, I knew I may have to perform a theft system relearn. Not the case. The key would not learn and the engine would not start. I tried doing the manual relearn procedure but it would not take. So I went ahead and connected to GM TIS2Web and performed a VTD relearn.
The procedure went well and the engine started but all of the anti theft messages and lights were on and would not go out. I rechecked the codes and now I had two codes: B3031 and B3055. Code B3031 means that the PK3 module is in assembly learn mode. The code B3055 means that a key has not been detected, it would make sense then that it could not be learned. It was also an old code. I called a locksmith friend of mine and asked if he could test the key for me. He did and it tested good. We went ahead and made another brand new key just in case (B3055 previously stored) but that did not work either. Time to do some research.
I found a document #PIC3895 that applied to my situation. The subject of the document is DTCs B3031 and B3055 being set after PK3 module replacement. It applies to the model year 2000 Cadillac Deville made prior to VIN breakpoint YU315493. The VIN on this car was YU24**** so it was definitely made prior.
That document was issued after the TSB # 00-02-35-006 that pointed out the change from a plastic lock cylinder housing to a metal lock cylinder housing. The change was made because of plastic debris entering the lock cylinder and causing it to stick and or bind in the housing.
I do not understand why it is not stated plainly in the Service Information but here is what I understand happened.
The manufacturer initially used a plastic lock cylinder housing during production. Early on they determined that plastic shavings were entering the lock cylinder and causing it to stick. There was a running change made to the design of the housing changing it from plastic to metal. The original PK3 module would not work with the new metal design so it had to be changed as well. Good, problem resolved.
I was sold part number 10355946 (shown below) which is the correct replacement part for the PK3 module. However according to the VIN I should have been sold a number 26089463 kit which includes a new metal lock cylinder housing.
It would seem the repair and parts supply side of the system may have been overlooked. Or it may have been, as it was in my case, the parts department did not use the VIN in looking up the replacement part. The original TSB#00-002-35-006 was issued in August of 2000. GM issued the PIC3895 document on Febuary1, 2006. At that point GM documented that the original plastic lock cylinder housing would not work properly with the replacement PK3 module and it had to be replaced with the metal housing.
I am very thankful that GM issued PIC3895 so that those of us on the service side could determine the cause of the DTCs B3031 and B3055. My problem was caused by being sold the 10355946 when I should have been sold the 26089463 kit.
The first picture below shows the new PK3 module while the second picture shows the old PK3 module. They look alike except for the label.
The old PK3 module and plastic lock cylinder housing.
The housing attaches with two screws at the left of the housing. Those two screws are hidden under the steering column locking plate.
There is a third screw that is located to the right center in the next picture.
The new metal lock cylinder housing and PK3 module installed.
The keys were learned when installed to the new assembly as they should have been originally. I did not show all of the details of replacing these parts since you have to have specialized tools and experience to complete it. My main goal was to help other professional mechanics that may not have access to factory service bulletins.