Explaination of three-character engine codes?

MarkEHansen

New member
Jan 1, 2019
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Sacramento, CA
I see references to three-character engine codes and have searched for an explanation, but can't find anything. Is there a sticky or some other reference where I can find these defined?


Also, how to do I determine what I have? I just purchased a 2019 GMC 3500 Denali HD with the 6.6L Duramax TD.


Thanks,
 

Bdsankey

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Feb 1, 2018
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I see references to three-character engine codes and have searched for an explanation, but can't find anything. Is there a sticky or some other reference where I can find these defined?


Also, how to do I determine what I have? I just purchased a 2019 GMC 3500 Denali HD with the 6.6L Duramax TD.


Thanks,

You have a L5P.

01-04: LB7
04.5-05: LLY
06-07: LLY & LBZ (same engines, different calibration)
08-10: LMM
10-16: LML
17+: L5P

This list is for pickup trucks, I do not know the van codes.
 

DAVe3283

Heavy & Slow
Sep 3, 2009
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Boise, ID, USA
The 3 letter codes are known as Regular Production Option (RPO) codes, and it is a system used by GM since at least the 90s to track what options a vehicle was built with. There is a Service Parts IDentification (SPID) label on vehicles up to 2018 that shows what RPOs it is equipped with. During 2018, they transitioned from a label readable by humans to using a QR code located on the weight rating sticker in the doorjam.

If you scan that QR code, it will list the RPOs your truck is built with, one of which will be L5P (the latest generation Duramax).

SPID Label Content Now Included with Certification Label

Posted on May 20, 2017 by blogadmin
The Service Parts Identification (SPID) label, often located in the trunk or glovebox of a vehicle, lists a vehicle’s VIN, RPO codes and other information that identify the content of the vehicle. Beginning with the 2018 model year, much of this information will be available through a QR code on the Certification label (Fig. 1) on all Buick, Cadillac, Chevrolet and GMC models. The change will be phased in over the next several months.

F01-cert-label.png

Fig. 1

The two-dimensional QR code is a simple barcode that offers the former SPID information in a digital format. The Certification label on all GM models is located on the driver-side B pillar, with the exception of the Corvette where it’s on the driver’s door.

QR Code

Software to read the QR code is commonly available for any Android, iPhone or Windows smartphone. Many basic applications can be downloaded for free. Tested QR code readers that are easy to use include NeoReader by NM LLC, i-nigma by 3GVision, QR Scanner by Honestly App, QR Droid by DroidLa and Bar-Code by PW2. GM does not recommended any particular software.

Once the QR code is scanned, the vehicle information will appear in the following order: VIN, Model Year, Model, Build Month, Year, Engineering Book, Vehicle Order Number, 3 Digit RPO Codes sorted alphanumerically, and the Paint Code (same code appears in the lower left of the QR code).

For example, here’s the information as shown from a scanned QR code:

1GNKVGKD1HJ263691,2017,CV14526,03,16,17,TSNWHZ, AG5 AH5 AR9 AXP AYQ C67 DLT DS3 EF7 FE2 GZW IPC I17 JL9 LLT MAH M7X NP5 NT7 QD6 QLW TB4 UI2 UQF U2K V8D WMH X88 1LT 17U 5PK 6AB 7AB 8UM 83C 83I 9UM,636R, , , ,

The RPO codes are bolded above, but not in the actual information. The codes are separated by a space. Up to 48 RPO codes may be displayed. RPO descriptions can be found in the appropriate Service Information under General Information.

If the vehicle information needs to be retained for service records or shared with others, most scanner software also has a selection to email the data. (Fig. 2)

F02-cert-label-email.png

Fig. 2
 

JoshH

Daggum farm truck
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Feb 14, 2007
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Texas!!!
The 3 letter codes are known as Regular Production Option (RPO) codes, and it is a system used by GM since at least the 90s to track what options a vehicle was built with. There is a Service Parts IDentification (SPID) label on vehicles up to 2018 that shows what RPOs it is equipped with. During 2018, they transitioned from a label readable by humans to using a QR code located on the weight rating sticker in the doorjam.

If you scan that QR code, it will list the RPOs your truck is built with, one of which will be L5P (the latest generation Duramax).

That is interesting. I never knew that.
 

Bdsankey

Vendor
Vendor/Sponsor
Feb 1, 2018
4,165
1,274
113
Larsen, Wisconsin
The 3 letter codes are known as Regular Production Option (RPO) codes, and it is a system used by GM since at least the 90s to track what options a vehicle was built with. There is a Service Parts IDentification (SPID) label on vehicles up to 2018 that shows what RPOs it is equipped with. During 2018, they transitioned from a label readable by humans to using a QR code located on the weight rating sticker in the doorjam.

If you scan that QR code, it will list the RPOs your truck is built with, one of which will be L5P (the latest generation Duramax).

That is interesting. I never knew that.

News to me also, kinda neat.
 

MarkEHansen

New member
Jan 1, 2019
2
0
0
Sacramento, CA
I suppose the "appropriate service information under General Information" is referring to the service manual, which I can order from, for example, Helm, Inc?

Thanks for this information. Great to know!
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,727
296
83
Boise, ID, USA
I suppose the "appropriate service information under General Information" is referring to the service manual, which I can order from, for example, Helm, Inc?

Thanks for this information. Great to know!
I usually just Google the RPO code. You can find 90% of them without too much effort. Or Google "GM RPO codes" and look for websites with big lists of them. I don't know of any one master list, besides asking the dealer.
 

2004LB7

Well-known member
Dec 15, 2010
6,989
2,146
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Norcal
this is the most complete list of RPO codes i've found
 

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