1995 Geo Metro Base, 2D HatchbackFACTORY 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 from 15-amp FI fuse through main relay. Main relay power is supplied from 15-amp IG fuse. ECM memory power is supplied from 15-amp TAIL fuse. FI, IG and TAIL fuses are 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
Metro Underneath Dash, Behind Glove Box
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.
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When to See a Mechanic

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

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