H43 - Check HO2S Heater Relay Circuit For Short to Power

- Key "OFF".

- Heated Oxygen Sensor (HO2S) relay disconnected.

- Breakout box installed, leave Powertrain Control Module (PCM) disconnected.

- Measure the resistance between test pin 14 and test pins 37/57 at the breakout box.

- Is the resistance greater than 10,000 ohms?

Yes -- Go to H44

No -- Service short in harness. Remove breakout box. Reconnect all components. Rerun Quick Test.