Standard Ignition TCS21 Automatic Transmission Control Solenoid

Automatic Transmission Control Solenoid for GM Applications

Standard Ignition TCS21 is an automatic transmission control solenoid built for specific GM shift and lockup applications. It uses a metal body, a rectangular female connector, and a push-on attachment method for direct replacement service on listed vehicles.

Compatible With select Buick, Chevrolet, Cadillac, Oldsmobile, and Pontiac models from 1991-2005, including Chevrolet Impala, Buick Regal, and Pontiac Grand Prix applications. Standard Ignition TCS21 is a fitment-specific transmission solenoid for automatic transmission control and shift operation.

• Brand: Standard Ignition
• Part number: TCS21
• Automatic transmission control solenoid for listed GM vehicles
• Metal construction with one rectangular female connector
• Push-on attachment method
• Gaskets included for service replacement
• Male blade terminals, 2-terminal design
• Cross-reference: Rostra Powertrain Controls 52-0348

Detailed Product Overview

This Standard Ignition TCS21 solenoid is used in a range of GM automatic transmissions where shift control, 1-2 and 3-4 shift operation, or torque converter clutch lockup control is required. Fitment includes 1991-2005 Chevrolet Impala, 1991-1999 Buick Century, 1998-1999 Buick Regal, 1994-1999 Chevrolet Lumina, 1997-1999 Chevrolet Monte Carlo, 1991-1996 Buick Park Avenue, and additional Cadillac, Oldsmobile, and Pontiac models listed below. The part number TCS21 is also referenced in service listings for Buick Regal, Pontiac Grand Prix, and Oldsmobile Cutlass applications.

What It Helps Correct

• Harsh, delayed, or inconsistent automatic shifting
• Transmission codes related to shift solenoid performance
• Loss of 1-2 or 3-4 shift control on listed applications
• Torque converter clutch lockup concerns on supported vehicles
• Transmission operation issues tied to a failed control solenoid

Installation Notes and Tips

Verify the transmission type and connector style before ordering. This part is specific to automatic transmissions only, and some fitments note application-specific use such as shift solenoid, shift control solenoid, or on-off lockup solenoid service. Confirm the vehicle year, make, model, and transmission pan or solenoid configuration against the listing for proper installation.

Quality Assurance

Standard Ignition states that its manufacturing process is controlled from component sourcing through finished product inspection, with broad sensor and service coverage for professional repair needs. That quality focus supports consistent replacement performance for the listed automatic transmission applications.