Vehicle applicability: This diagnostic supplement covers multiple Ford vehicles and engines. Follow the application named in the source below. Some references apply to vehicles other than Mustang.
Powertrain DTC Charts and Descriptions 4-11
Diagnostic Trouble Code (DTC) Charts and Descriptions
P0036 - HO2S Heater Control Circuit (Bank 1, Sensor 2)
Description: The PCM controls the heated oxygen sensor bank 1, sensor 2 (HO2S12) heater ON and OFF duty cycle to
maintain a calibrated temperature. This DTC sets when the sensor does not warm up to the required temperature in a calibrated amount of time. This DTC also sets when the PCM is not able to maintain the required temperature after the sensor is warm.
Possible Causes: • VPWR circuit open
• HTR12 circuit open
• HTR12 circuit short
• Incorrect connections
• Damaged or corroded pins
• Exhaust temperature significantly higher than expected
• Damaged HO2S12
Diagnostic Aids: Inspect the connectors for signs of damage, water intrusion or corrosion.
Application Key On Engine Off Key On Engine Running Continuous Memory
All GO to Pinpoint Test DW.
P0037 - HO2S Heater Control Circuit Low (Bank 1, Sensor 2)
Description: The PCM controls the heated oxygen sensor bank 1, sensor 2 (HO2S12) heater ON and OFF duty cycle to
maintain a calibrated temperature. This DTC sets when the sensor does not warm up to the required temperature in a calibrated amount of time. This DTC also sets when the PCM is not able to maintain the required temperature after the sensor is warm.
Possible Causes: • HTR12 circuit short
• Incorrect connections
• Damaged or corroded pins
• Exhaust temperature significantly higher than expected
• Damaged HO2S12
Diagnostic Aids: Inspect the connectors for signs of damage, water intrusion or corrosion.
Application Key On Engine Off Key On Engine Running Continuous Memory
All GO to Pinpoint Test DW.
P0038 - HO2S Heater Control Circuit High (Bank 1, Sensor 2)
Description: The PCM controls the heated oxygen sensor bank 1, sensor 2 (HO2S12) heater ON and OFF duty cycle to
maintain a calibrated temperature. This DTC sets when the sensor does not warm up to the required temperature in a calibrated amount of time. This DTC also sets when the PCM is not able to maintain the required temperature after the sensor is warm.
Possible Causes: • HTR12 circuit short
• Incorrect connections
• Damaged or corroded pins
• Exhaust temperature significantly higher than expected
• Damaged HO2S12
Diagnostic Aids: Inspect the connectors for signs of damage, water intrusion or corrosion.
Application Key On Engine Off Key On Engine Running Continuous Memory
All GO to Pinpoint Test DW.
P0040 - Oxygen Sensor Signals Swapped Bank 1 Sensor 1/Bank 2 Sensor 1
Description: The heated oxygen sensor (HO2S) monitor determines if the universal HO2S signal response for a fuel shift
corresponds to the correct engine bank. This DTC sets when there is no response from the universal HO2S being tested.
Possible Causes: • Crossed universal HO2S harness connectors
• Crossed universal HO2S wiring at the harness connectors
• Crossed universal HO2S wiring at the PCM connectors
Diagnostic Aids: Connect the universal HO2S connector to the correct bank.
Application Key On Engine Off Key On Engine Running Continuous Memory
All GO to Pinpoint Test DZ.
2016 Powertrain Control/Emissions Diagnosis, Gasoline Engines, 3/2015
2016 Mustang workshop publication supplied to Mustang Atlas. Original technical text and illustrations; HTML formatting by Mustang Atlas. Source page numbering is retained for traceability. Follow the configuration, revision, warnings, and cross-references in the material. About this edition.