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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 P0136: 1/2 O2 Sensor Heater Circuit Malfunction >> Testing
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DTC P0136: 1/2 O2 Sensor Heater Circuit Malfunction: Testing

  1. Turn ignition on, engine off. Using scan tool, read DTCs. If GOOD TRIP counter is displayed for DTC P0136 and displayed count is "0", go to next step. If GOOD TRIP counter is not displayed for DTC P0136 or displayed count is not "0", go to step  8.
  2. Turn ignition off. Check for blown fuse "U" (20-amp), located in Power Distribution Center (PDC). PDC is located in engine compartment, next to battery. See Figure. This is the fuse for oxygen sensor relay. If fuse "U" is blown, go to next step. If fuse "U" is not blown, go to step  4.
  3. Ensure fuse "U" is removed from PDC. Remove oxygen sensor relay from PDC. Using DVOM, measure resistance between ground and oxygen sensor relay cavity No. 86 (Orange/Dark Green wire) in PDC. See Figure. If resistance is 5 ohms or more, replace fuse "U". If resistance is less than 5 ohms, repair short to ground in Orange/Dark Green wire between fuse "U" and oxygen sensor relay cavity No. 86 in PDC. Replace fuse "U".
  4. Ensure ignition is off. Remove oxygen sensor relay from PDC. Using DVOM, measure resistance between oxygen sensor relay terminals No. 85 and 86 (component side). See Figure. If resistance is 100 ohms or less, go to next step. If resistance is more than 100 ohms, replace oxygen sensor relay.
  5. Ensure ignition is off. Using DVOM, measure resistance between joint connector No. 1 terminal No. 6 (Orange/Dark Green wire) in PDC and oxygen sensor relay terminal cavity No. 86 (Orange/Dark Green wire) in PDC. See Figure. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Orange/Dark Green wire between joint connector No. 1 and oxygen sensor relay.
  6. Ensure ignition is off and oxygen sensor relay is removed. Disconnect PCM connectors. PCM is located in engine compartment on passenger-side inner fender panel. Using DVOM, measure resistance of Dark Green/Black wire between oxygen sensor relay cavity No. 85 in PDC and PCM harness connector C3 terminal No. 9. See Figure and Figure . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Dark Green/Black wire between PCM and oxygen sensor relay cavity No. 85 in PDC.
  7. Ensure ignition is off and PCM connectors are still disconnected. Using DVOM, measure resistance between ground and oxygen sensor relay cavity No. 85 (Dark Green/Black wire) in PDC. If resistance is 5 ohms or more, replace PCM. If resistance is less than 5 ohms, repair short to ground in Dark Green/Black wire between PCM and oxygen sensor relay cavity No. 85 in PDC.
  8. Start engine and allow engine to idle. Wiggle wiring harness and connectors between PCM, fuse "U" (20-amp) and oxygen sensor relay while noting GOOD TRIP counter. PCM is located in engine compartment on passenger-side inner fender panel. Fuse "U" and oxygen sensor relay are located in PDC. Downstream oxygen sensor relay may be referred to as oxygen downstream relay. If GOOD TRIP counter does not change to "0" while wiggling wiring harness and connectors, go to next step. If GOOD TRIP counter changes to "0" while wiggling wiring harness and connectors, repair wiring or connectors between PCM, fuse "U" or oxygen sensor relay as necessary.
  9. Shut engine off. Ensure ignition is off. Disconnect PCM connectors. Inspect PCM connectors for corroded, pushed out, miswired or damaged terminals. Inspect wiring harness between PCM, fuse "U" and oxygen sensor relay for any possible intermittent problems. Also, check for related Technical Service Bulletins (TSBs). If terminals are not corroded, pushed out or damaged and wiring harness is okay, test is complete. If terminals are corroded, pushed out or damaged, or wiring harness is damaged, repair as necessary.
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