LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mercedes Benz >> 2001 >> ML430 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0160: Left O2 Sensor Downstream TWC (G3/5) >> Testing Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Testing Procedure

  1. O2 Signal -  Connect DVOM between ME-SFI control module connector "D" terminals No. 10 and 9 (socket box terminals No. 42 and 41). Start engine and idle. Keep engine speed between 2000-3000 RPM for approximately 2 minutes after engine coolant temperature reaches more than 176°F (80°C). Allow engine to idle. Voltage must exceed or drop below range of 450-500 millivolts once within one minute. If voltage is okay, go to next step. If voltage is not okay, possible causes are left O2 sensor (after TWC) heater failure, wiring harness failure, defective left O2 sensor (after TWC - G3/5) or defective ME-SFI control module (N3/10). To check left O2 sensor (after TWC) heater failure, go to DTC P0161: O2 SENSOR HEATING OF LEFT O2 SENSOR DOWNSTREAM TWC (G3/5)  .
    NOTE: Manufacturer recommends using socket box for jumpering terminals in next step.
  2. Connect jumper wire between ME-SFI control module connector "A" terminal No. 3 (socket box terminal No. 3) and ME-SFI control module connector "E" terminal No. 10 (socket box terminal No. 66). Air pump should run and voltage should change to less than 40 millivolts within one minute. Connect jumper wire between ME-SFI control module connector "A" terminal No. 3 (socket box terminal No. 3) and ME-SFI control module connector "C" terminal No. 28 (socket box terminal No. 20). Air pump should run and voltage should change to less than 40 millivolts within one minute. If air pump responds and voltage changes, test is complete. If air pump does not respond or voltage does not change, possible causes are left O2 sensor (after TWC) heater failure, wiring harness failure, defective left O2 sensor (after TWC - G3/5) or defective ME-SFI control module (N3/10). To check left O2 sensor (after TWC) heater failure, go to DTC P0161: O2 SENSOR HEATING OF LEFT O2 SENSOR DOWNSTREAM TWC (G3/5)  .
scientia non olet · About LEMON Manuals