Help me make the definitive S-Chassis VIN/Model decoder

[InvisibleHand]

Hey! Long time lurker here. I mostly come here to search for answers for my S14 build, but today I want to ask the community to help me with something directly.

I am building an S-Chassis registry app that decodes VIN and Model codes and provides all the factory specs of the car (from S12 to S15). Then based on the number of cars registered and the specific configuration of each car, it tells you the rarity of any specific option, and the rarity of the overall configuration.

I have been doing extensive research to document every digit's purpose and all possible S-Chassis-related variables per digit. Unfortunately, there is a lot of conflicting or outright missing information out there. The primary resources I am using are:

nissanhelp.com VIN decoder
gtr-registry.com S-Chassis portals
240sx.org S-14 Model Identification document
Various VIN related posts here on zilvia.net

If you don't have any specific knowledge, the next best thing you can do is list your car's VIN (minus the last 6 digits which are the serial number, for your privacy) as well as your Model Code, along with the year, model and factory options of your car so I can begin to identify the pattern within the code.

Here is what I have so far. Please help me fill in the gaps and correct any errors.

Let's begin with the VIN.

All S-Chassis' will begin with:

• JN1: Japanese Nissan Passenger Vehicle
• JN3: Japanese Nissan Convertible

Digits 4-9 are the VDS or Vehicle Description Section:

• 4th Digit: The VIN decoder claims this is the engine option but I don't think this is right. For instance, my 240sx has A here and came stock with a KA24DE. But the site says A is for VG, VK and VQ motors. The list has the KA24DE as D. What's the truth about this digit?
• 5th Digit: Chassis code - All S-Chassis will have S here, with the exception of S12's which I believe have a C. Please correct me if I'm wrong.
• 6th Digit: VIN decoder calls this the "model change" but the info is lacking. Looking at some info this may denote models in the following format:

  180sx = 3
  200sx = 2
  240sx = 4 (This is consistent with my car)
  Silvia = 6

• 7th Digit: Body Type - 4 is 2-Dr Coupe and 6 is 2-Dr Vert and Fastback
• 8th Digit: Misc, primarily focused on safety features from what I can tell. My car has D which according to the VIN decoder means "Driver & Front Passenger Air Bag + 3 Point Seat Belt". I will need some help determining how many of these variables will apply to our cars.
• 9th Digit: Check Digit - Of no real significance.

Digits 10-17 are the VIS or Vehicle Identifier Section:

• 10th Digit: Model Year - I have info for S13 through S15, but am missing S12. It is as follows:

  L = 1990
  M = 1991
  N = 1992
  P = 1993
  R = 1994
  S = 1995
  T = 1996
  V = 1997 (consistent with my car)
  W = 1998
  X = 1999
  Y = 2000
  1 = 2001
  2 = 2002

• 11th Digit: Plant Code - I believe all S-Chassis were build in Kyushyu, Japan, which is represented by W.
• 12th-17th Digits: Serial Number specific to each individual car.

Additionally, I have found that Japanese market car VINs or Chassis Numbers are structured differently with just 9-10 digits vs 17 in the U.S. Are there any other differences like this in other markets such as Europe and Australia?

On to the Model Code:
I have only been able to find the S14 code breakdown from 240sx.org (linked above) This looks very accurate to me. But I need similar resources for S12, S13 and S15. If anyone has a similar doc to the S14 one please link it here. Otherwise, this is where listing your specific code, configuration and options will help me decipher it for all S-Chassis.

Thanks in advance for your help! Let's make the most comprehensive database of code specs and the most efficient car registry on the internet! The registry app is just the start but is the biggest hurdle. I think the whole S-Chassis community will like what I have planned once that's launched!

Cheers!

[C. Anderson]

I pulled this from Nissan FAST and is for the US s13.

[C. Anderson]

This is the S14 breakdown from US FAST.

[mav1178]

pretty much the FAST info above is what is available.

FSM has no other info to help any more.

[AKADriver]

All US S14s will have 4th digit (engine code) A in the VIN AFAIK. The VIN of the '95 my S14 block came from was JN1AS4 etc. US S13s will have an H there for the SOHC and M for DOHC.

5th digit is the letter of the chassis code and 6th digit is the ones digit of the chassis code. S12 = S2. S13 = S3. S14 = S4. Z32 = Z2.

For the 8th digit I think all US S14s should be D and all US S13s should be P. Not sure what Canadian S13s have for the 8th digit since they have no passive restraint.

[mav1178]

Originally Posted by AKADriver

For the 8th digit I think all US S14s should be D and all US S13s should be P. Not sure what Canadian S13s have for the 8th digit since they have no passive restraint.

8th digit on Canadian S13 is S for Standard, P for (USDM) Automatic.

verified via GI-15 page in FSM and also the CDM S13 in my garage.

[InvisibleHand]

This is a great start! Keep it coming. Looks like the details for North American S-Chassis are almost complete. Details for Japanese, Euro and Australian markets are still mostly a mystery to me though.

Originally Posted by C. Anderson

I pulled this from Nissan FAST and is for the US s13.

These model code docs are solid. Does anyone have these for either the S12 or S15?

AKABriver & Mav1178 - This is super helpful. Thank you!

[AKADriver]

JDM chassis numbers are just in the format: model code-serial number

I'm not 100% sure what the first digit of the serial number is though. Every S13 Silvia I've seen has a '0' there (eg (KP)S13-0xxxxx). 180SXs have a ton of different things there: I've seen '6' and '8' on zenkis, '0', '2', '3', and '5' on chukis, '3' and '5' on koukis.

With the S14 Silvia it's more clear cut, S14-0xxxxx is a zenki and S14-1xxxxx is a kouki. CS14 is HICAS.

[mav1178]

Originally Posted by AKADriver

JDM chassis numbers are just in the format: model code-serial number

I'm not 100% sure what the first digit of the serial number is though. Every S13 Silvia I've seen has a '0' there (eg (KP)S13-0xxxxx). 180SXs have a ton of different things there: I've seen '6' and '8' on zenkis, '0', '2', '3', and '5' on chukis, '3' and '5' on koukis.

With the S14 Silvia it's more clear cut, S14-0xxxxx is a zenki and S14-1xxxxx is a kouki. CS14 is HICAS.

the prefix letters for JDM cars is just the chassis, engine, or HICAS (or not)

https://www.180sx.club/nissan-s13-ch...des-explained/

P = SR
K = HICAS
R = fastback (180SX) body style

Also this provides context, Nissan uses 6 digits so if the vehicle never made it to 100000 units produced of that model (all variations of fastback SR, for example) then the first digit will never be anything other than 0.

https://carvx.jp/chassis-number