Emissions

P2216 — NOx Sensor Positive Current Control Circuit Open (Bank 2 Sensor 1)

Severity: medium Drive with care, to a shop

What P2216 means

The engine control unit monitors the electrical circuits of the nitrogen oxide (NOx) sensor in the exhaust. P2216 means it detected an open in the positive current control circuit of the bank 2 sensor 1 NOx sensor. The SCR system relies on this sensor to dose urea (DEF/AdBlue) accurately, so without a valid signal NOx control suffers.

Symptoms

  • Check Engine light on
  • SCR or DEF system warning message
  • Possible reduced engine power
  • Higher than normal DEF consumption
  • Warning of a no-restart condition after a set distance
  • Increased NOx emissions

Possible causes

  1. Failed bank 2 NOx sensor
  2. Open wire in the sensor harness
  3. Corroded or damaged connector terminals
  4. Connector left unplugged after exhaust service
  5. Wiring shorted to battery positive
  6. Faulty NOx sensor control module or ECU (rare)

How to diagnose

  1. Read all codes and freeze frame data and look for other SCR or NOx codes
  2. Inspect the bank 2 NOx sensor connector for a secure latch, corrosion, moisture, and bent pins
  3. Inspect the harness along the exhaust for chafing, heat damage, and past repairs
  4. Check power and ground at the sensor connector using the factory wiring diagram
  5. Test the circuit wires for opens and shorts to voltage
  6. Compare NOx sensor readings on a scan tool with the engine running
  7. If wiring is good, replace the sensor and verify the repair

Common fixes

  • Reconnect and secure the sensor connector
  • Clean or replace damaged connector terminals
  • Repair or replace the damaged harness section
  • Replace the bank 2 NOx sensor
  • Clear codes and road test to confirm

Questions and answers

What does P2216 mean?

The ECU detected an open in the positive current control circuit of the bank 2 sensor 1 NOx sensor. The sensor, its connector, or its wiring is usually at fault.

Can I drive with P2216?

For a short time, yes, but the exhaust aftertreatment is not working properly. Power reduction or restart problems may follow, so get it diagnosed soon.

Should I replace the NOx sensor right away?

No. Check the connector and wiring first, especially after exhaust work. The sensor is expensive and the fault is often a bad connection.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.