OBD-II trouble code
P2213: NOx Sensor Circuit (Bank 2)
A general circuit fault on the bank 2 nitrogen oxide sensor. Before anything is tested, establish which physical sensor this address actually refers to on your vehicle — on a great many diesels there is no second cylinder bank, and the manufacturer has used the bank 2 numbering for a second sensor in the same exhaust stream.
Quick facts
- System
- Powertrain
- Category
- Auxiliary Emissions Controls
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $60 – $1,400
- DIY difficulty
- Intermediate DIY
Browse every code in P2200–P229F, or start from the full code library.
What does P2213 mean?
This code opens the bank 2 half of the nitrogen oxide sensor block, and the first thing it demands is an identification rather than a measurement.
Bank 2 has a standard definition: the side of a cylinder bank arrangement that does not contain cylinder number one. That definition is easy to apply to a V engine and meaningless on an inline four, which is what a large proportion of the diesels that carry nitrogen oxide sensors actually have. Those vehicles still set bank 2 codes, because the manufacturer has used the second set of addresses for the second sensor in a single exhaust stream — commonly the one downstream of the selective catalytic reduction catalyst, where the system checks its own work. Which of those two situations applies to the vehicle in front of you changes the part number, the location, the labour and in some cases the entire diagnostic direction, and no amount of testing will tell you if you have started from the wrong assumption. Look the addressing up in service information before ordering anything.
The second thing worth establishing is what the word circuit means on a device like this one. A nitrogen oxide sensor is not a probe that hands an analog voltage back to the engine controller. The element sits in the exhaust and is wired to a small sealed control unit a short distance along the harness, and that control unit conditions the signal, regulates the heater, runs self-tests and then reports a finished value to the engine controller over a dedicated communication link. Very little of the path the code names carries anything a meter can interpret as a signal.
That changes the leading suspicion. When the engine controller flags a general circuit fault on this address, the usual physical reality is not a shorted signal wire — it is silence. The controller expected messages from a device that is no longer sending any, either because the device has lost its power supply, because the link between the two has been interrupted, or because the sensor's own electronics have shut down and stopped reporting. A sensor that has gone quiet and a sensor that is physically disconnected look identical from the controller's point of view, which is why the supply and the connector are worth more early attention than the element ever is.
There is a diagnostic shortcut available on this code that does not exist on the bank 1 equivalent, and it costs nothing. Read the whole code set before touching the vehicle. If the corresponding bank 1 code is stored alongside this one, two independent sensors have not failed on the same day; something they share has. The shared items are a short list — a supply feed, a ground point, a fuse, a relay, the communication link itself, or the controller at the far end of it — and checking those five first is a far better use of the first hour than testing either sensor. If this code is stored alone, the fault is confined to this sensor's own branch, and the branch is where to look.
Practical location matters here too. Where a genuine second bank exists, its sensor commonly sits on the side of the engine that is harder to reach, and the harness run from it is the longer of the two, crossing more clips, more heat shields and usually a flexing junction between the engine and the body. Longer runs with more interfaces fail more often than short ones, which is an unglamorous but real reason bank 2 sensors are diagnosed more frequently than bank 1 sensors on the same vehicle.
The vehicle normally drives. Expect a warning light, the loss of the emissions monitor this sensor supports, and on diesels the prospect of a reduced-power inducement strategy if the fault is left unrepaired long enough for the system to conclude it cannot verify its own emissions performance.
Common causes
- Loss of the supply voltage or ground that powers the sensor's own control unit
- Open or damaged communication link between the sensor control unit and the engine controller
- Connector at the sensor control unit corroded, backed out, or water-contaminated
- Blown fuse or failed relay feeding the sensor assembly
- Harness chafed through where the bank 2 run crosses a heat shield, clip or engine-to-body junction
- Failed nitrogen oxide sensor whose internal electronics have stopped reporting
- Element cracked by thermal shock, taking the sensor's self-test out with it
- Soot or condensate contamination inside the connector body
- Aftermarket or incorrect sensor fitted that the controller does not recognise
- Rarely, a fault in the engine controller or the aftertreatment control module at the far end of the link
Symptoms
- Check engine light with an emissions or exhaust system message
- Emissions readiness monitor that will not complete
- Reductant dosing behaviour that changes or stops
- Reduced power inducement on diesels if the fault persists
- No drivable symptom at all in the early stages
- Fuel economy drifting slightly worse over time
- Failed emissions or roadworthiness test
- Corresponding bank 1 nitrogen oxide code stored at the same time
- Sensor value missing entirely from live data rather than reading incorrectly
Diagnostic steps
- 1.Establish which physical sensor the bank 2 address maps to on this vehicle. On an inline engine there is no second cylinder bank, so the address belongs to a second sensor in the same stream — service information will say which, and everything after this step depends on the answer.
- 2.Read the complete code set before testing anything. A matching bank 1 code alongside this one points at something the two sensors share rather than at either sensor.
- 3.Check whether the sensor appears in live data at all. A value that is absent or flagged invalid indicates the controller is receiving nothing, which is a different fault from a value that is present but wrong.
- 4.Verify the fuse and relay feeding the sensor assembly, and confirm supply voltage and ground quality at the sensor's control unit connector with the circuit loaded.
- 5.Inspect the connector for corrosion, moisture, backed-out terminals and spread contacts, and check the seal rather than only the pins.
- 6.Follow the harness along its full run with the engine warm, paying particular attention to heat shield edges, clip points and any section that crosses between the engine and the body.
- 7.Check the communication link between the sensor control unit and the engine controller for continuity and for a short to ground or to voltage.
- 8.Wiggle-test the connector and harness while monitoring whether the sensor reappears in live data.
- 9.Confirm the fitted sensor is the correct part for the vehicle and the position, since a substituted part frequently will not be recognised.
- 10.If supply, ground, link and connector all check good and the sensor still does not report, replace the bank 2 sensor assembly and re-verify.
Repair cost
$60 – $1,400
Diagnosis runs $110 to $250, and on this code the time is genuinely spent on identification and wiring rather than on the sensor. A fuse, a corroded pin or a chafed wire repair can close the job for $60 to $300. A nitrogen oxide sensor is an expensive smart sensor: $250 to $900 for the part depending on the vehicle, with $100 to $350 in labour on top and the bank 2 position usually the dearer of the two to reach. Budget toward the upper end on trucks and on engines where the sensor sits against the bulkhead.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with nox sensor replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.