What is the only serviceable part of the transmission electronic control unit (ECU)?

What is the only serviceable part of the transmission electronic control unit (ECU)?

• A. Shift lever
• B. Throttle position sensor
• C. PROM chip
• D. Hall effect switches

Answer: (C)

The part that determines how and when the transmission shifts is stored in memory inside the ECU, and the only component meant to be serviced or replaced in the field is the PROM chip that holds the shift maps and calibration data. Replacing or updating this chip changes how the ECU interprets inputs (like speed and engine load) to decide gear changes. The shift lever is simply a driver input, and the throttle position sensor and Hall effect switches are external sensors or inputs, not internal serviceable ECU parts. So the PROM chip is the only component designed for field servicing because it contains the program the ECU uses to control shifting.

The part that determines how and when the transmission shifts is stored in memory inside the ECU, and the only component meant to be serviced or replaced in the field is the PROM chip that holds the shift maps and calibration data. Replacing or updating this chip changes how the ECU interprets inputs (like speed and engine load) to decide gear changes. The shift lever is simply a driver input, and the throttle position sensor and Hall effect switches are external sensors or inputs, not internal serviceable ECU parts. So the PROM chip is the only component designed for field servicing because it contains the program the ECU uses to control shifting.