Open or damaged heater element inside the NOx sensor itself; Broken, corroded, or disconnected wiring in the heater control circuit; High resistance at the sensor connector or ground point; Faulty heater control driver inside the engine control module (ECM); Blown fuse or relay supplying power to the NOx sensor heater; Aftermarket or incorrect sensor installed previously; Contamination or mechanical damage to the sensor from exhaust leaks or coolant intrusion

DTC codes / P22xx · Fuel and air metering (injector circuits) / P2207

P2207NOx Sensor Heater Control Circuit High (Bank 1 Sensor 1)

Q: What does code P2207 mean?

NOx Sensor Heater Control Circuit High (Bank 1 Sensor 1). P2207 means the engine computer has detected an abnormally high voltage on the heater control circuit for the upstream nitrogen oxide (NOx) sensor on bank 1. The computer expects the heater circuit to draw current within a specific range, and a high-voltage condition tells it the circuit is open, has excessive resistance, or the sensor's internal heater has failed.

P2207 means the engine computer has detected an abnormally high voltage on the heater control circuit for the upstream nitrogen oxide (NOx) sensor on bank 1. The computer expects the heater circuit to draw current within a specific range, and a high-voltage condition tells it the circuit is open, has excessive resistance, or the sensor's internal heater has failed.

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 engine power or limp mode in some vehicles as a protective strategy
Slightly rough running or hesitation during regeneration events
Poor fuel economy if the fault affects closed-loop NOx control
In rare cases, a burning smell from the sensor area if the heater circuit overheats
Failed emissions inspection due to the stored fault

Common causes, most likely first

Open or damaged heater element inside the NOx sensor itself
Broken, corroded, or disconnected wiring in the heater control circuit
High resistance at the sensor connector or ground point
Faulty heater control driver inside the engine control module (ECM)
Blown fuse or relay supplying power to the NOx sensor heater
Aftermarket or incorrect sensor installed previously
Contamination or mechanical damage to the sensor from exhaust leaks or coolant intrusion

How to diagnose and fix it

Scan all modules and record freeze-frame data to confirm the fault is current and not history
Inspect the NOx sensor connector and harness for corrosion, chafing, or loose pins
Measure heater circuit resistance at the sensor and compare to the manufacturer's specification
Check for battery voltage and ground at the heater control circuit with the key on
Test the heater control driver output from the ECM with a bidirectional scan tool or oscilloscope
Replace the NOx sensor if the heater element is open or out of specification
Clear codes and perform a road test to verify the repair and confirm the monitor runs

Why a NOx heater code is not always the sensor

A high-voltage code often points to an open circuit rather than a shorted sensor, so a simple resistance check at the connector can save you from replacing a good sensor.
The heater control driver inside the ECM can fail and set this code even when the sensor and wiring test perfectly, so always verify driver output before condemning the module.
Corrosion inside the connector pins is a frequent hidden cause, especially on vehicles that see road salt or frequent pressure washing.
Some vehicles set P2207 as a companion code to a NOx efficiency fault, and repairing only the heater circuit will not resolve the underlying sensor performance issue.
A blown fuse that feeds the NOx heater may also power other emissions components, so check related circuits before assuming the sensor is at fault.

Can I keep driving with P2207?

You can usually drive the vehicle short distances to a repair shop, but avoid heavy loads and long trips because the engine may enter limp mode or fail emissions testing. If the check engine light begins flashing or you notice a strong burning smell, stop driving and have the vehicle towed.

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.