MSD 75591 Programmable Shifter Controller for 2–6 Speed Transmissions

The MSD 75591 Programmable Shifter Controller gives racers and performance enthusiasts precise RPM-based control over automatic transmission shift points. By allowing users to program custom RPM trigger points for each shift solenoid, this controller delivers consistent, repeatable shifts optimized for performance driving and competition use.

Key Features:

• Programmable RPM shift points to trigger transmission shift solenoids
• Compatible with any transmission configuration from 2 to 6 speeds
• Cylinder count configurable for 4, 6, or 8-cylinder engines (default: 8)
• Supports both Sequence-On (12V) and Pulsed solenoid types
• Pulsed solenoid activation time adjustable from 0.100 to 2.5 seconds in 0.010-second increments
• Six status LEDs on the end panel for at-a-glance diagnostics
• Aluminum construction for durability in high-performance environments
• Programming performed via MSD Pro-Data+ Software (Windows-based PC) or MSD Hand-Held Monitor PN 7550 (sold separately)

What's Included:

• Shift controller
• MSD Pro-Data+ software
• 9-pin harness — 10 ft.
• 1-pin harness
• Deutsch terminated harnesses
• Butt splices
• Ring terminals
• Screws, nuts, and washers

The MSD 75591 is a universal, non-application-specific shift controller ideal for drag racing, road racing, and high-performance street builds where precise transmission control is critical. Backed by MSD's 1-year limited warranty when purchased from an authorized dealer.