Understanding JLR Part Numbers: LR137929 vs. L8B2-10C784-BB

JLR Parts Explained: LR137929 vs. L8B2-10C784-BB for the BECM

When searching for a replacement Battery Energy Control Module (BECM) for your Land Rover or Range Rover PHEV, you'll likely come across two different numbers: LR137929 and L8B2-10C784-BB. They refer to the same part, but it's important to understand the difference.

L8B2-10C784-BB: The Engineering Part Number

• This is the number assigned to the part during the design and manufacturing phase by Jaguar Land Rover's engineering department.
• You will typically find this number printed or stamped directly on the physical part itself.
• The format (letters-numbers-letters) is a hallmark of an engineering number. It helps engineers track revisions and production batches. For example, a later revision might end in ‘BC' instead of ‘BB'.

LR137929: The Service Part Number

• This is the official part number used by JLR's parts and service network (i.e., dealerships and parts suppliers).
• This is the number you should use when ordering the part.
• A single service part number can ‘supersede' multiple older engineering numbers. For instance, if an improved version of the BECM is released, JLR might assign it a new engineering number, but the service part number you order (e.g., LR137929) will ensure you receive the latest, correct version.

Which Number Should You Use?

When ordering a replacement, always use the service part number (LR137929). This guarantees you are requesting the correct part through the official supply chain.

The engineering number (L8B2-10C784-BB) is most useful for confirming that the physical part you are holding is the one you intended to order. If you remove your old BECM, you can use the engineering number on its label to help identify the correct service part number you need to buy.

At SX-Tool, we list both numbers on our product pages to help you confirm you are ordering the right component with confidence.