What it means
The dedicated O2 sensor control module - found on systems with a wide-band sensor needing its own pumping current driver - reports its supply voltage outside the calibrated window.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Some wide-band oxygen sensors use a dedicated control module to drive the sensor's pumping current and report oxygen readings to the engine control module. P055E sets when that dedicated module reports supply voltage outside its calibrated window, which can disrupt oxygen feedback and emissions control.
Common causes
Most likely first.
- Oxygen sensor control module supply voltage low or unstable
- Charging system voltage problem
- Loose, corroded, or damaged module power or ground connection
- Module or wiring fault
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
How to diagnose it
- Record freeze-frame data and check live oxygen-sensor and fuel-trim data for signs that feedback stopped or became unstable.
- Inspect the oxygen-sensor control module power, ground, and connector for looseness, corrosion, heat damage, or water entry.
- Check battery and charging-system voltage under the conditions shown in freeze-frame data.
- Test the module's supply and ground circuits for voltage drop, opens, and shorts against the manufacturer's specification.
- If supply and wiring are correct, test the oxygen-sensor control module and associated harness using the manufacturer's procedures.
Common fixes
- Clean and secure the module's power or ground connection.
- Repair damaged supply or ground wiring.
- Correct a charging-system fault causing unstable system voltage.
- Replace the oxygen-sensor control module if it fails testing.
Can I keep driving?
The vehicle may run roughly, use more fuel, or fail an emissions test, so limit unnecessary driving and avoid hard acceleration if it hesitates. If it stalls or runs very poorly, stop driving and have it checked.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.