Short answer: GM part numbers are 8 digits, such as 12654321. A GM module label often shows more than one 8-digit number. Look for the one marked as the service or part number, and search that first.
Numbers you’ll see on a GM module label
- Service or part number: the number GM sells the part under. On many engine and transmission modules it’s labeled “SVC” or “Service No.”
- Hardware or base number: identifies the physical unit. Several service numbers can share one hardware number.
- Calibration or software numbers: the programming loaded on the unit. These change with updates and aren’t the best search number.
What to search
Search the service number first. If that finds nothing, try each other 8-digit number on the label. Older GM numbers are sometimes replaced by newer ones, so a dealer may quote a different number for the same part.
Frequently asked questions
Will a GM module work if only the calibration number is different?
Usually the module can be reprogrammed to the right calibration, but it depends on the part. Match the service number and let us know if you need help.
Do GM modules need programming?
Most GM engine, transmission and body modules need to be programmed to the vehicle. See Do I need to program a replacement module?
Find your module
Search the part number from your module’s label on Module Mountain, or shop by vehicle. Every module is refurbished to order, ships free by USPS Priority in the USA, and is covered by our one-year warranty (exchange and warranty policy). Can’t find your number? Email contact@modulemountain.com with a photo of the label and your VIN.