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Vehicle Info NeededMSD IGNITIONPART NUMBER: 121-2771
Transmission Control Unit Wiring Harness for 2009-Up GM 4L70 Transmissions
$20795
Ships on Sep 03, 2026
Lowest Price GuaranteeController Harnesses - GM
Replacement Wiring Harness for a Transmission Control UnitFits 2009-Up GM 4L70 Transmissions Only Connects the Controller to the Transmission Application Specific Harness
A standalone transmission controller has to match the connector and pinout of the transmission it is wired to, and those differ from one unit to the next. This is the application specific harness for a GM 4L70, so the controller plugs into the factory transmission connector without splicing or pin swapping.
MSD 2771 Transmission Control Unit Wiring Harness Features:
- Connects a transmission control unit to the transmission.
- For 2009 and later GM 4L70 transmissions only.
- Application specific connector and pinout.
- These MSD Transmission Controller Harnesses are designed to connect an Atomic TCM to your transmission. Proper wiring connector included for a perfect fit.
Part TypeAutomatic Transmission Wiring Harness
Product LineMSD Transmission Controller Harnesses
BrandMSD IGNITION
Package Height3.2
Package Width6.4
Package Length6.6
Weight0.83 PG
Part CategoryPerformance Parts
QuantitySold Individually
Part FitmentSemi Universal
Grade TypePerformance
Vendor Part Number2771
Package Qty1
Package TypeEA
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