P1127 Possible Causes
What does this mean?
- Faulty O2 sensor heaters
- O2 sensor heater element circuit is open or shorted
- Poor electrical connection in the O2 sensor heater circuit
How to fix code P1127?
Start by checking the “possible causes” listed above. Visually inspect the corresponding wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
Possible Symptoms
- Check engine light on (or service engine soon warning light)
P1127 Meaning
The Heated Oxygen Sensor (HO2S) monitor uses an exhaust temperature model to determine when the HO2S heaters are activated. The test fails when the inferred exhaust temperature is below a minimum calibrated value.
Information for specific brands
- P1127 AUDI Long term fuel trim system B1 too rich
- P1127 FORD Exhaust not hot enough Downstream O2 sensor not tested
- P1127 HYUNDAI Long term fuel trim system rich error
- P1127 LEXUS ECTS actuator power source circuit malfunction
- P1127 LINCOLN Exhaust not hot enough Downstream O2 sensor not tested
- P1127 MERCURY Exhaust not hot enough Downstream O2 sensor not tested
- P1127 TOYOTA ETCS actuator power source circuit malfunction
- P1127 VOLKSWAGEN Long term fuel trim system B1 too rich