ISUZU Amigo/Pick-ups/Rodeo/Trooper 1981-1996

Electronic Control Module (ECM)



When the term Electronic Control Module (ECM) is used in this manual it will refer to the engine control computer regardless that it may be a Vehicle Control Module (VCM), Powertrain Control Module (PCM) or Electronic Control Module (ECM).

The Electronic Control Module (ECM) is required to maintain the exhaust emissions at acceptable levels. The module is a small, solid state computer which receives signals from many sources and sensors; it uses these data to make judgments about operating conditions and then control output signals to the fuel and emission systems to match the current requirements.

Engines coupled to electronically controlled transmissions employ a Powertrain Control Module (PCM) or Vehicle Control Module (VCM) to oversee both engine and transmission operation. The integrated functions of engine and transmission control allow accurate gear selection and improved fuel economy.

In the event of an ECM failure, the system will default to a pre-programmed set of values. These are compromise values which allow the engine to operate, although at a reduced efficiency. This is variously known as the default, limp-in or back-up mode. Driveability is almost always affected when the ECM enters this mode.


See Figure 1

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Fig. Fig. 1: The ECM can usually be found in front of the center console, under the dash-except Hombre

  1. Disconnect the negative battery cable. Disable the SRS system if equipped.
  3. Remove any trim panel necessary to access the ECM.
  5. Disengage the connectors from the ECM.
  7. Remove the spring retainer off and over the rail of the ECM.
  9. Slide the ECM out of the bracket at an angle.
  11. Remove the ECM.

To install:
  1. Install the ECM into the bracket.
  3. Install the spring retainer and engage the electrical connectors.
  5. Install any components removed to access the ECM.
  7. Connect the negative battery cable.