[Keith Seymore]

Originally Posted by GTO JOHN

I don't know what the numbers mean but there is definetly a pattern. The Body numbers are all over the place but the 6 digit numbers always stay in order.

I have the following info:

VIN build date Body # 6 digit #
B107678 09C 503204 016031
B110236 09C 516654 021668
B122223 10D 527185 044554
B125043 10E 530927 050164
B126014 10E 533488 052040
B127747 10E 527794 055508
B137436 11D 544610 073643
B150249 01B 558552 089157
B151222 01B 548953 101016
B151829 01B 557813 102579
B156002 01D 558063 116620
B156677 02A 566342 118620
B163075 03A 566274 138132
B164889 03B 573646 144717
B166394 03C 574614 149430

There is another 6 digit number we haven't discussed yet: It's called the "Carrier Sequence Number", or CSN. It is very similar to the body "gate" or fixture number that has already been mentioned, except that rather than being a one or two digit number (ie, 1 - 14) is a six digit code and represents an internal fixture.

Basically, the flow of information goes like this:

The dealer initiates the order which is tracked by the Dealer Order Number. This is an alpha numeric code (there doesn't seem to be any pattern in terms of sequence or alpha characters, like "PAE175", or "JDCXZB" or "JDCW65"). This number is used to track the vehicle/order until it reaches the vehicle assembly plant.

Once the order is screened for correctness and material availability and passes this check it is "committed" to the assembly plant. At this point the CSN is established. Vehicles are built in CSN order and are tracked through the body shop and paint shop until the VIN is established and affixed to the body. Once the VIN is established it takes precedence over the CSN.

(Incidently, in my most recent assembly plant - the Mishawaka H2 plant, to be specific - the vehicles pop off the end of the line in CSN order, not VIN order).

Here are some carriers in an assembly plant, to give you a flavor of what I am talking about:


I tried to find in my files some matrices that showed actual vehicles being tracked by the Order Number, CSN, VIN and GM Company Owned Vehicle Number (for GM pre-production vehicles) but I didn't have any; the reason being is once I had the VIN I deleted the CSN because I no longer cared. I had the VIN and the GM vehicle number and with those two numbers I could track any vehicle through any durability testing/validation testing, Captured Test Fleet usage or retrofit activities and subsequent sale or auction.

I mention all this because I wonder if the six digit codes you are seeing are the equivalent of what I am calling the CSN.

Disclaimer:

I base this on my experience in GM assembly plants, which started in 1979. I have built preproduction properties in every GM Full Size Truck assembly plant in North America over the last 30 years, so while I have lots of truck experience I have zero experience building Pontiacs or Chevys in Baltimore. I share these thoughts, which may or may not apply here, in the hopes that this may further stimulate your own thoughts/theories.

FWIW -

K