1995 Geo Prizm Base, AutomaticFACTORY OEM SERVICE PROCEDURE

Engine Control Module (ECM)

NOTE: ECM is also known as Powertrain Control Module (PCM). All references to ECM include PCM unless specified otherwise.

Power for ECM is supplied through the EFI F-HTR fuse, located in fuse/relay block. The ECM distributes power or controls ground of various sensors, switches and solenoids for engine control.

ECM LOCATION

Application Location
Prizm In Front Of Center Console, Under Heater Blower Case
NOTE: Components are grouped into 2 categories. The first category is INPUT DEVICES, which are components that control or produce voltage signals monitored by the ECM. The second category is OUTPUT SIGNALS, which are components controlled by the ECM.
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.