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Home >> Dodge and Ram >> 2001 >> Durango 5.9 Z, 4WD, Part Time >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0161: 2/2 O2 Sensor Heater Failure >> Testing
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DTC P0161: 2/2 O2 Sensor Heater Failure: Testing

  1. Turn ignition on, engine off. Using scan tool, read DTCs. If GOOD TRIP counter is displayed for DTC P0161 and displayed count is "0", go to next step. If GOOD TRIP counter is not displayed for DTC P0161 or displayed count is not "0", go to step  3.
  2. Turn ignition off. Wait a minimum of 8 minutes to allow 2/2 HO2S to cool down (voltage should stabilize to 0.4-0.6 volt). Turn ignition on, engine off. Using scan tool, actuate HO2S HEATER TEST and monitor 2/2 HO2S voltage for 2 minutes. If voltage stays at 0.4-0.6 volt, go to next step. If voltage does not stay at 0.4-0.6 volt, go to step  7.
  3. Turn ignition off. Allow 2/2 HO2S to cool down to room temperature. Disconnect 2/2 HO2S connector. Measure resistance between 2/2 HO2S connector heater element terminals No. 1 and No. 2. See Figure. Resistance should be within specification. See O2 SENSOR HEATER RESISTANCE SPECIFICATIONS  table in DTC P0032. If resistance is not within specification, replace 2/2 HO2S. If resistance is within specification, 2/2 HO2S heater element is okay. Go to next step.
  4. Ensure ignition is off. Disconnect PCM connectors. PCM is located in engine compartment on passenger-side inner fender panel. Measure resistance of heater ground circuit between 2/2 HO2S harness connector terminal No. 1 (5.9L), or No. 2 (4.7L) and ground point. See 2/2 HO2S TERMINAL IDENTIFICATION  table. See Figure. Ground point is located on right front side of engine block. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black/White wire (4.7L) or Black wire (5.9L) between 2/2 HO2S and ground point.
  5. Ensure ignition is off and 2/2 HO2S is still disconnected. Reconnect PCM connectors. Turn ignition on, engine off. Using scan tool, actuate HO2S HEATER TEST. Measure voltage between ground and fused ignition circuit (Dark Green/Pink wire) at 2/2 HO2S harness connector terminal No. 1 (4.7L) or No. 2 (5.9L). See Figure. If voltage is more than 11 volts, go to next step. If voltage is 11 volts or less, repair open in Dark Green/Pink wire between 2/2 HO2S and oxygen sensor relay. Oxygen sensor relay is located in Power Distribution Center. PDC is located in engine compartment, next to battery. See WIRING DIAGRAMS article.
  6. At this time, PCM is assumed to be defective. Replace PCM.
  7. At this time, conditions for DTC P0161 to set do not exist or fault is an intermittent problem. Start engine and allow it to idle. Ensure engine is at normal operating temperature. Using scan tool, monitor 2/2 HO2S voltage while wiggling connectors and wiring harness from 2/2 HO2S to Powertrain Control Module (PCM). PCM is located in engine compartment on passenger-side inner fender panel. If voltage changes while wiggling connectors and wiring harness, repair connectors and wiring harness where wiggling caused voltage to change. If voltage does not change, review FREEZE FRAME DATA using scan tool. Attempt to duplicate condition that caused DTC P0161 to set by paying special attention to the conditions during which 2/2 HO2S is monitored. Check for any related Technical Service Bulletins (TSBs) that may apply. Visually inspect related connectors and wiring harness. Repair connectors and wiring harness as necessary. See WIRING DIAGRAMS article. If no problems are indicated, test is complete.
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