P2592

NOx Sensor Circuit High Input Bank 2 Sensor 2

P2592 is a generic OBD-II powertrain diagnostic trouble code: NOx Sensor Circuit High Input Bank 2 Sensor 2. It is logged by the engine control unit when the powertrain monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.

Code
P2592
Group
Powertrain
System
Powertrain
Severity
Warning (MIL on)
Need P2592 disabled?
RaceTune permanently disables any OBD-II trouble code on supported ECUs — for motorsport, off-road, and export use.
→

What P2592 means

P2592 indicates that the powertrain control module (PCM) has detected a voltage signal from the downstream NOx sensor on Bank 2 (Sensor 2) that is above the expected operating range. The NOx sensor is a critical component of the selective catalytic reduction (SCR) system, measuring residual nitrogen oxide concentration in the exhaust stream after the SCR catalyst.

A high circuit signal can result from an open circuit in the reference or signal wiring, a short to voltage in the sensor harness, an internal sensor failure, or a faulty PCM input circuit. The ECU relies on this sensor to verify SCR conversion efficiency and to adjust diesel exhaust fluid (DEF) dosing accordingly. When the signal is out of range, closed-loop NOx control is disrupted.

This fault typically illuminates the malfunction indicator lamp (MIL) and may affect emissions compliance reporting. In some vehicles, extended operation with this fault can trigger a torque de-rate or regeneration inhibit as a secondary protective measure. Diagnosis should begin with a thorough inspection of the sensor connector and harness before component replacement.

Common causes

Most-frequently reported root causes when P2592 is logged.

  • 1
    Open circuit in the NOx sensor signal or reference wire on Bank 2 Sensor 2.
  • 2
    Short to battery voltage in the NOx sensor harness.
  • 3
    Failed or contaminated downstream NOx sensor (Bank 2 Sensor 2).
  • 4
    Corroded or damaged sensor connector causing high resistance.
  • 5
    PCM internal fault affecting the sensor input circuit.
  • 6
    Incorrect sensor installed (wrong part number or cross-contamination).
  • 7
    Exhaust system leak near the sensor skewing readings high.

Symptoms drivers notice

MIL (check engine light) illuminated.
Possible increase in tailpipe NOx emissions.
DEF consumption may become irregular or excessive.
Potential torque de-rate warning on the instrument cluster.
SCR system efficiency monitoring fault logged alongside this code.

How to diagnose P2592

A typical diagnostic flow when this code is present.

  1. 1
    Connect a scan tool and record all stored DTCs and freeze-frame data.
  2. 2
    Inspect the Bank 2 Sensor 2 NOx sensor connector and wiring harness for damage, corrosion, or chafing.
  3. 3
    Check for battery voltage shorts in the sensor signal circuit using a multimeter.
  4. 4
    Verify sensor supply voltage and ground at the connector with the ignition on.
  5. 5
    Compare live NOx sensor data on Bank 2 Sensor 2 against Bank 1 values and expected range.
  6. 6
    Clear the DTC and perform a road test to confirm whether the fault resets.
  7. 7
    Replace the NOx sensor if wiring and connector checks are normal and the fault returns.

Vehicles where we've handled P2592

Platforms in our catalogue with confirmed P2592 coverage.

BMW 320D
2016

Related powertrain codes

Frequently asked questions

Can I drive with P2592 active?

Short-term driving is generally possible, but prolonged operation may trigger a torque de-rate or fail an emissions test. Repair promptly.

Is P2592 always a bad sensor?

Not necessarily. Wiring faults, connector corrosion, and PCM issues can all produce a high circuit signal. Inspect the harness thoroughly first.

Will P2592 cause excessive DEF usage?

Yes, if the SCR controller loses confidence in the sensor signal it may revert to open-loop dosing, which can alter DEF consumption rates.

Does P2592 affect SCR catalyst efficiency?

The fault prevents closed-loop NOx feedback, so the system cannot confirm SCR conversion efficiency, which may lead to elevated tailpipe NOx.

Disabling P2592 in software

RaceTune can permanently disable P2592 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.

Permanent
The monitor is disabled in the ECU itself — not just cleared. It cannot return.
Tailored to your file
Each patch is matched to your specific software version — never a one-size-fits-all file.
Reversible
The original file is always preserved. Reflash the stock to return the ECU to factory state.

ECUs with a P2592 disable in our catalogue

Confirmed coverage from our recipe database — we support many more families. Upload your file and our identifier will match it automatically.

  • Bosch EDC17C50 verified 1 software version

Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.

Got P2592 in your scan?

Upload your ECU file — we'll identify the exact software version and confirm whether a disable is available for your car.

Upload your file