Testing Procedure
- CAN Data Bus - Connect DVOM between ME-SFI control module connector "D" terminal No. 11 and 12 (socket box terminals No. 43 and 44). Turn ignition off. Resistance should be 55-65 ohms. If resistance is within specification, go to next step. If resistance is not within specification, possible causes are Controller Area Network (CAN) failure. Go to next step.
- Turn ignition off. Disconnect ME-SFI control module connector "D". Connect DVOM between ME-SFI control module connector "D" terminals No. 11 and No. 12 (socket box terminals No. 43 and 44). Resistance should be 115-125 ohms. If resistance is within specification, go to next step. If resistance is not within specification, possible causes are wiring harness failure, electronic ignition switch control module (N73) defective on C class, CLK class and E class or instrument cluster (A1) defective on ML320. Repair as necessary.
- Turn ignition off. Disconnect ME-SFI control module connector "D" from test cable (socket box) and reconnect to ME-SFI control module. Connect DVOM between ME-SFI control module connector "D" terminals No. 11 and No. 12 (socket box terminals No. 43 and 44). Resistance should be 115-125 ohms. If resistance is within specification, test is complete. If resistance is not within specification, possible cause is Engine Control Module (N3/10) defective. Repair as necessary.