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

  1. Turn ignition on. Using scan tool, check for DTCs. If GOOD TRIP counter for DTC P0136 is displayed and displayed count is "0", go to next step. If GOOD TRIP counter for DTC P0136 is not displayed or displayed count is not "0", go to step  7 .
  2. Turn ignition off. Remove and inspect fuse No. 10 (15-amp) fuse from junction block. Junction block is located behind passenger-side kick panel. If fuse is okay, go to step  4 . If fuse is blown, go to next step.
  3. Remove HO2S downstream heater relay from Power Distribution Center (PDC). See Figure . PDC is located in right side of engine compartment, next to battery. Measure resistance between ground and terminal C18 (White wire) at HO2S downstream heater relay socket in PDC. See Figure . If resistance is 5 ohms or more, circuit is okay. Replace fuse. If resistance is less than 5 ohms, repair short to ground in White wire. Replace fuse.
  4. Remove HO2S downstream heater relay from PDC. See Figure . Measure resistance between terminals No. 85 and 86 at downstream heater relay. See Figure . If resistance is 100 ohms or less, go to next step. If resistance is more than 100 ohms, replace relay.
  5. Measure resistance of White wire between terminal C18 at HO2S downstream heater relay socket in PDC and output side of fuse holder for fuse No. 10 in junction block. See Figure . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in White wire.
  6. Ensure ignition is off. Disconnect Powertrain Control Module (PCM) connectors. PCM is located in engine compartment on left front fender, near radiator support. Measure resistance of Brown/Violet wire between terminal C16 at HO2S downstream heater relay socket in PDC and terminal No. 9 at PCM C3 harness connector. 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 Brown/Violet wire.
  7. Turn ignition off. Visually inspect related connectors and wiring harness for damage. Repair connectors and wiring harness as necessary. If connectors and wiring harness are okay, reconnect all connectors. Start engine. Wiggle related connectors and wiring harness while monitoring scan tool display. If GOOD TRIP counter display count changes to "0", repair connector or wiring harness where wiggling caused display to change. If GOOD TRIP counter display count does not change to "0", no problem is indicated at this time. Check for any related technical service bulletins that may apply.
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