Montero Sport ECU/ECM and PCM Information ...
Listed below are the Mitsubishi part numbers and vehicle production dates for various Engine Control Modules (ECM) (also known as an Engine Control Unit (ECU)). This list only addresses ECMs and PCMs (Powertrain Control Module) for the 3.0L and 3.5L 4-wheel drive Montero Sport from 1997 through 1999.
Federal Emissions 3.0L(2 O2 sensors)
- MD338139 - 9-1-96/2-3-97
- MD349089 - 3-1-97/5-3-97
- MD349506 - 6-1-97/5-3-98
- MD357512 - 1-6-98/3-5-99
- MD357515 - after 3-5-99/?
California Emissions 3.0L(4 O2 sensors)
- MD338138 - 9-1-96/2-3-97
- MD357511 - 1-6-98/3-5-99
- MD357513 - after 3-5-99/? (A/T)
Federal Emissions 3.5L(2 O2 sensors)
- MD357516 - 6-1-98/5-3-99 (A/T)
- MD364531 - 9-1-98/5-3-99 (A/T) (gear ratio change)
California Emissions 3.5L(4 O2 sensors)
- MD357514 - 6-1-98/5-3-99 (A/T)
- MD364530 - 9-1-98/5-3-99 (A/T) (gear ratio change)
Factory Montero Sport PCM & ECM Pin-Out Descriptions(not comprehensive)
Montero Sport ECM PCM Conversion Pin-Out Tables
Montero Sport ECM/PCM w/ Parallel MegaSquirt III Pin-Outs & Wiring Diagrams
Montero Sport ECM/PCM w/ Parallel (piggyback) AEM F/IC and Innovate Wideband O2 Pin-Outs & Wiring Diagrams
The tabular ECM/PCM pin-out guide contained in the Mitsubishi Montero Sport factory service manuals does not contain a complete listing of all ECM/PCM pin-outs. Additional pin-outs are documented throughout each year's service manual volumes.
The ECM harness to PCM conversion and parallel MegaSquirt installation are as yet untested. The documentation is as through and precise as we could make it but without an actual installation the functionality is unconfirmed.
MD338139 and MD349089 are interchangeable on the '97 Montero Sport LS 3.0L 4-wheel drive. Performance over 3000 RPM is better with the MD338139 but there is a significant low end torque increase below 3000 RPM with the MD349089 ECU.