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DTC P0044: Rear Ho2S Heater Circuit High: Testing

NOTE: Ensure freeze frame data has been recorded. Check for service bulletins and on-line information.
  1. Turn ignition off. Disconnect rear O2 sensor. Check connectors for damaged terminals and corrosion. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, go to step  5 .
  2. Check resistance between sensor connector terminals "A" and "B". If resistance is 16 ohms, go to next step. If resistance is not 16 ohms, replace rear O2 sensor and go to step  5 .
  3. Turn ignition off. Disconnect PCM connector. PCM is mounted to passenger floor, behind glove box. Check harness connector and PCM terminal No. 96 for damaged terminals and corrosion. If no problem is found, go to next step. If problem is found, repair as necessary. After repair, go to step  5 .
  4. Turn ignition on. Check voltage between rear O2 harness connector terminal "B" (Light Green wire) and ground. If battery voltage is not present, go to next step. If battery voltage is present, repair short to power on circuit between sensor and PCM and go to next step.
  5. Reconnect all components. Using scan tool, clear DTC. Start engine and allow to reach operating temperature. Using scan tool, check or DTC P0044. If DTC P0044 is not pending, go to next step. If DTC P0044 is pending, replace PCM and go to next step.
  6. Perform after repair procedure. See AFTER REPAIR PROCEDURE  . If no DTC is present, testing is complete. If any DTC is present, go to appropriate test for diagnosis and repair.
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