LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 2009 >> Flex Limited, FWD >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Controls - Powertrain DTC Charts & Descriptions (Except Diesel & Hybrid) >> DTC Diagnosis >> DTC P0030: - Ho2S Heater Control Circuit (Bank 1, Sensor 1)

DTC P0030: - Ho2S Heater Control Circuit (Bank 1, Sensor 1)

DTC P0030: - HO2S HEATER CONTROL CIRCUIT (BANK 1, SENSOR 1)

Description:  The powertrain control module (PCM) monitors the heater in the heated oxygen sensor (HO2S) for correct operation. The PCM controls the heater on/off duty cycle to maintain a temperature of 780°C (1,436°F). The test fails when the sensor does not warm up to the required temperature in a calibrated amount of time. The test also fails when the PCM is not able to maintain the required temperature after the sensor is warm.
Possible Causes: 
  • Open UO2S circuit
  • Open UO2SGREF circuit
  • Open UO2SHTR circuit
  • UO2SHTR circuit short to voltage
  • Loose connection, and damaged or corroded terminals
  • Exhaust temperature significantly higher than expected
  • Damaged universal HO2S
Diagnostic Aids:  Inspect the connectors for signs of damage, water ingress, or corrosion.
Application  Key On Engine Off  Key On Engine Running  Continuous Memory 
All - GO to Pinpoint Test DZ . GO to Pinpoint Test DZ .