Open or damaged wire in the NOx sensor heater circuit, often due to chafing or corrosion.; Failed NOx sensor heater element, which can burn out internally.; Blown fuse or faulty relay that supplies power to the heater circuit.; Poor electrical connection at the sensor or PCM connector, including loose pins or water intrusion.; PCM internal driver failure, though this is less common.; Aftermarket sensor with incorrect resistance causing the PCM to set the code.

DTC codes / P22xx · Fuel and air metering (injector circuits) / P2205

P2205NOx Sensor Heater Control Circuit/Open (Bank 1 Sensor 1)

Q: What does code P2205 mean?

NOx Sensor Heater Control Circuit/Open (Bank 1 Sensor 1). P2205 indicates that the powertrain control module (PCM) has detected an open circuit or excessive resistance in the heater circuit of the upstream nitrogen oxide (NOx) sensor on bank 1. The PCM commands a heater duty cycle to bring the sensor to operating temperature, but the feedback voltage or current does not match the expected value, so the heater is considered faulty or disconnected.

P2205 indicates that the powertrain control module (PCM) has detected an open circuit or excessive resistance in the heater circuit of the upstream nitrogen oxide (NOx) sensor on bank 1. The PCM commands a heater duty cycle to bring the sensor to operating temperature, but the feedback voltage or current does not match the expected value, so the heater is considered faulty or disconnected.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms.
Reduced fuel economy because the engine may enter a default fueling strategy.
Possible rough running or hesitation if the fault affects closed-loop operation.
In some vehicles, a message indicating emissions system service required.
Intermittent warning light if the open circuit is temperature or vibration sensitive.

Common causes, most likely first

Open or damaged wire in the NOx sensor heater circuit, often due to chafing or corrosion.
Failed NOx sensor heater element, which can burn out internally.
Blown fuse or faulty relay that supplies power to the heater circuit.
Poor electrical connection at the sensor or PCM connector, including loose pins or water intrusion.
PCM internal driver failure, though this is less common.
Aftermarket sensor with incorrect resistance causing the PCM to set the code.

How to diagnose and fix it

Inspect the NOx sensor heater fuse and replace if blown, then recheck for the code.
Visually inspect the sensor wiring and connector for damage, corrosion, or loose pins, and repair as needed.
Measure the resistance of the heater element across the sensor terminals and compare to the manufacturer's specification.
Check for power and ground at the heater connector with the key on and the PCM commanding the heater on.
Perform a voltage drop test on the heater circuit to identify excessive resistance in the wiring.
If the circuit tests good, replace the NOx sensor with a quality OEM or equivalent part.
Clear the code and verify the repair by running the appropriate monitor or test drive.

Before you replace the NOx sensor

A blown fuse for the NOx heater is often caused by a shorted sensor heater, so replacing only the fuse will lead to a repeat failure.
The heater circuit is live only when the PCM commands it on, so a simple key-on voltage check may not reveal an open circuit; use a scan tool to command the heater on.
Corrosion inside the connector pins can create enough resistance to set P2205 without any visible wire damage, so always inspect the terminals closely.
Some vehicles use a smart NOx sensor with an integrated control module, and a heater circuit fault may be stored in that module rather than the PCM, requiring a different diagnostic approach.
P2205 can be set by a low battery or charging system issue that causes the PCM to see implausible heater feedback, so check system voltage first.

Can I keep driving with P2205?

You can usually continue driving with P2205, but the vehicle may fail an emissions inspection and fuel economy may suffer. Avoid long periods of idling or heavy load until the fault is repaired, and address it promptly to prevent damage to the NOx sensor or catalytic converter.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.