P1127 MERCURY Possible Causes
- 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 P1127 MERCURY code?
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 soon-to-be-service engine warning light)
P1127 MERCURY 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.