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Home >> Mercedes Benz >> 2002 >> SL600 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics With Codes >> Diagnostic Tests >> DTC P0161: O2 Sensor Heating Of Left O2 Sensor Downstream TWC (G3/5) >> Testing Procedure
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Testing Procedure

NOTE: For ME-SFI control module location and identification, see ME-SFI CONTROL MODULE CONNECTOR IDENTIFICATION  .
  1. Actuation -  Connect DVOM between left cylinder bank ME-SFI control module connector 1 terminals No. 12 and No. 25 (socket box terminals No. 12 and 25). Start engine and idle. Allow engine to idle for at least 2 minutes after engine coolant temperature reaches more than 176°F (80°C). Voltage should be 11-14 volts (voltage may fluctuate). If voltage is within specification, go to next step. If voltage is not within specification, possible causes are wiring harness failure, O2 sensor (G3/5) failure or defective left cylinder bank ME-SFI control module (N3/11).
  2. Current Consumption -  Turn ignition off. Connect ammeter between left cylinder bank ME-SFI control module connector 1 terminals No. 26 and 12. (socket box terminals No. 26 and 12). Turn ignition on. Ammeter should indicate 0.6-3.4 amps. If amperage is within specification, test is complete. If amperage is not within specification, possible causes are wiring harness failure, O2 sensor (G3/5) failure or defective left cylinder bank ME-SFI control module (N3/11). Repair as necessary.
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