5. FUEL INJECTION SYSTEM MXU 500EXi/MXU500i INSPECTION Outlook checking Checking for ECU pin(1-48) if has damage. Checking for ECU part number if is correct. 3920A-ALC1-E00 is correct-on road 3920A-AAA5-900 is correct-off road Voltage inspection Connect the meter (+) probe to the B4(R/W)wire and the meter (-) probe to the M3(G/B) wire to measure the voltage MAP content (edition issue no.) Performance confirmed 5-21