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P2215 — Nox Sensor Circuit Low Bank 2

Manufacturer-specificPowertrain (engine & transmission)

P2215 indicates that the nitrogen oxides (NOx) sensor on engine Bank 2 is reporting a circuit voltage or signal below the expected range. This usually points to a problem with the NOx sensor, its wiring, or the connector rather than the engine computer.

Symptoms

What causes it — most likely first

1. Faulty Bank 2 NOx sensor

The NOx sensor element or internal circuitry can fail, causing a low or out-of-range signal. This is the single most common cause of P2215.

2. Wiring short to ground or open circuit

The harness between the NOx sensor and the control module can chafe, corrode, or short to ground, pulling the circuit voltage low.

3. Connector damage or corrosion

Loose, corroded, or bent pins in the sensor or module connector can create excessive resistance or a poor signal path.

4. Exhaust leak or sensor contamination

Leaks near the sensor or contamination from coolant, oil, or fuel additives can skew readings and trigger circuit-related codes.

5. PCM/ECM internal fault

A rare control-module input or software issue can misread a good sensor signal; this should only be considered after the sensor and wiring are ruled out.

How it's diagnosed

  1. Visually inspect the Bank 2 NOx sensor connector and harness for corrosion, pin damage, chafing, or fluid intrusion.
  2. Check sensor power, ground, and signal circuit voltages with a scan tool and digital multimeter, comparing against service-data specifications.
  3. Look for exhaust leaks upstream of or near the Bank 2 NOx sensor that could affect readings.
  4. Perform a NOx sensor self-test or reset/learn procedure if the scan tool supports it.
  5. Verify the PCM/ECM has the latest applicable calibration before condemning the module.
  6. Only consider PCM replacement after confirming the sensor and all wiring/connectors are known-good.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationManufacturer-specific (P1/B1/C1/U1)

Frequently asked

Can I keep driving with P2215?

Short trips are usually possible, but prolonged driving is not recommended. Many vehicles will eventually enter limp mode, and the SCR emissions system will not function correctly.

Is P2215 usually caused by a bad PCM/ECM?

No. In most cases the problem is the NOx sensor, its wiring, or the connector. PCM failure is uncommon for this code and should only be suspected after the rest of the circuit has been thoroughly tested.

Which side of the engine is Bank 2?

Bank 2 is the cylinder bank that does not contain cylinder number one on V-configured engines. On inline engines there may be only one bank, so the code refers to the second NOx sensor location in the exhaust stream.

Will topping off DEF fix this code?

Usually not. Low DEF can cause other SCR-related codes, but P2215 specifically relates to the NOx sensor electrical circuit. Fix the sensor circuit first, then verify DEF quality and level separately.