Using Engine Signal Monitor

Using Special Service Tools (Engine Signal Monitor)
1. Check the mass air flow sensor for damage and cracks.
2. Remove the ECM.




3. Connect the Special Service Tools to the ECM.




4. Measure the voltage at the ECM terminal 3E.




5. If not as specified, inspect harness continuity:
- Between ECM terminal 3E and mass air flow sensor terminal B
- Between ECM terminal 40 and mass air flow sensor terminal A
- Between ECM terminal 4A and mass air flow sensor terminal C

6. If there is incorrect terminal voltage or harness continuity, replace the mass air flow sensor.