Standard Ignition SC28 Automatic Transmission Output Shaft Speed Sensor

Automatic Transmission Output Shaft Speed Sensor

Standard Ignition SC28 is an automatic transmission output shaft speed sensor built for direct-fit service on select Buick, Chevrolet, Oldsmobile, and Pontiac applications. It uses a female oval plug-in connector with two male blade terminals and trans-mount installation for a clean replacement on the transmission.

• Fits 1989-1991 Chevrolet Cavalier, w/ Digital Instrument Panel
• Fits 1989-1991 Pontiac Sunbird
• Fits 1990-1991 Buick Skylark
• Fits 1990-1991 Oldsmobile Cutlass Calais, 1 Hole Mounting
• Fits 1990-1991 Pontiac Grand Am

Key Features

• Standard Ignition SC28 automatic transmission output shaft speed sensor
• Female connector with oval shape and plug-in design
• 2 blade terminals with male terminal ends
• Mounts at the transmission for direct replacement service
• Built under controlled manufacturing processes for consistent sensor output and durability

Product Details

The SC28 is a transmission speed sensor used to monitor output shaft speed for the vehicle’s control and display systems. On applications such as the Chevrolet Cavalier with digital instrument panel, Pontiac Sunbird, Buick Skylark, Oldsmobile Cutlass Calais, and Pontiac Grand Am, accurate speed signal input is important for proper transmission-related operation and drivability. Standard Ignition manufactures this sensor with in-process quality control from component to finished part, helping maintain consistent performance and service life.

This part cross-references Dorman - HELP 31003 for the same application.

Common Issues This Part May Address

• Erratic or missing vehicle speed signal from the transmission
• Inoperative or inaccurate digital speed display on equipped models
• Transmission control concerns related to output shaft speed input
• Speedometer fluctuation caused by a failing transmission sensor
• Diagnostic trouble codes tied to output shaft speed sensor performance

Installation Notes

Verify connector style, terminal count, and trans-mount location before installation. On 1990-1991 Oldsmobile Cutlass Calais applications, confirm the 1-hole mounting configuration matches the vehicle. Inspect the harness connector and transmission mounting surface for damage, corrosion, or debris before installing the new sensor.

Quality Assurance

Standard Ignition maintains manufacturing control from component sourcing through final assembly, with sensor coverage built for domestic and import service needs. The SC28 is produced to support consistent electrical performance and long-term durability in transmission sensor applications.