Faulty NOx sensor itself, with an internal short or degraded sensing element biasing the signal high; Damaged or chafed wiring between the NOx sensor and the control module, shorting the signal wire to voltage; Corroded or loose connector pins at the sensor or module, adding resistance or intermittent contact; A shorted sensor heater circuit that bleeds voltage into the signal return; Contaminated sensor element from excessive oil consumption, coolant intrusion, or fuel additives; A software or calibration issue in the engine control module that misinterprets a valid sensor signal; Rarely, a failed engine control module driver for the NOx sensor circuit

DTC codes / P22xx · Fuel and air metering (injector circuits) / P2216

P2216NOx Sensor Circuit High Input (Bank 2 Sensor 1)

Q: What does code P2216 mean?

NOx Sensor Circuit High Input (Bank 2 Sensor 1). P2216 means the engine computer has detected an abnormally high voltage signal on the nitrogen oxide (NOx) sensor circuit for bank 2 sensor 1, which is the upstream NOx sensor on the bank of cylinders that does not contain cylinder 1. The computer expects the sensor's output to stay within a specific voltage range, and a sustained high reading tells it the circuit is either seeing too much voltage or the sensor is reporting a condition it should not.

P2216 means the engine computer has detected an abnormally high voltage signal on the nitrogen oxide (NOx) sensor circuit for bank 2 sensor 1, which is the upstream NOx sensor on the bank of cylinders that does not contain cylinder 1. The computer expects the sensor's output to stay within a specific voltage range, and a sustained high reading tells it the circuit is either seeing too much voltage or the sensor is reporting a condition it should not.

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 the computer limits torque to protect emissions components
Poor fuel economy if the system enters a default fueling strategy
Rough running or hesitation under light throttle in some applications
A message on the dash advising you to see a dealer or service emissions system
Failed state emissions inspection due to the stored fault

Common causes, most likely first

Faulty NOx sensor itself, with an internal short or degraded sensing element biasing the signal high
Damaged or chafed wiring between the NOx sensor and the control module, shorting the signal wire to voltage
Corroded or loose connector pins at the sensor or module, adding resistance or intermittent contact
A shorted sensor heater circuit that bleeds voltage into the signal return
Contaminated sensor element from excessive oil consumption, coolant intrusion, or fuel additives
A software or calibration issue in the engine control module that misinterprets a valid sensor signal
Rarely, a failed engine control module driver for the NOx sensor circuit

How to diagnose and fix it

Scan all modules for stored and pending codes, and record freeze-frame data to see the conditions when P2216 set
Inspect the NOx sensor wiring harness and connector for chafing, corrosion, or pushed-out pins, repairing as needed
Measure reference voltage and ground at the sensor connector with a multimeter to confirm the circuit is not shorted high
Check the sensor heater resistance and compare it to the manufacturer's specification to rule out a shorted heater
Perform a functional test of the NOx sensor with a scan tool that can read live NOx sensor voltage and compare it to expected values
If the circuit and heater test good, replace the bank 2 sensor 1 NOx sensor with a quality part and clear the codes
After repair, complete a drive cycle that includes the monitor conditions for the NOx sensor and verify the code does not return

What a high NOx signal really tells you

A high voltage reading does not automatically condemn the sensor; a short to voltage in the harness or a bad ground can produce the same signal, so circuit testing must come before parts replacement.
NOx sensors are heated and only begin reporting after a warm-up period, so a code that sets only when cold often points to a heater or supply voltage problem rather than the sensing element.
Bank 2 sensor 1 is the upstream sensor on the bank without cylinder 1, and on V6 and V8 engines that bank is often tucked against the firewall where heat and vibration damage wiring.
Some vehicles set P2216 when the engine control module detects an out-of-range signal during a self-test, even if the sensor later reads normally, so intermittent connector faults are a common root cause.
Replacing a NOx sensor without checking for exhaust leaks or excessive oil consumption can lead to a repeat failure, because contamination and upstream leaks skew the sensor's reading.

Can I keep driving with P2216?

You can usually drive the vehicle with P2216 set, but avoid heavy throttle and long trips until it is diagnosed, because the computer may be running a default fueling strategy that increases emissions and can damage the NOx sensor or catalytic converter over time. If the engine enters limp mode or you notice rough running, have it checked promptly.

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.