Failing NOx sensor and processor unit (the processor is often built into the sensor assembly); Damaged wiring, corrosion or poor connection in the sensor connector, including water ingress; Low or poor-quality exhaust fluid affecting the sensor readings and the plausibility checks; Exhaust leak near the sensor upstream of the sensor or contamination of the sensor tip; Supply voltage or earth problem affecting the processor, such as a weak battery or poor earth; Communication fault on the data network between the processor and ECU; Faulty ECU or outdated software where the manufacturer has documented a fault.

P06EB

NOx Sensor Processor Performance Bank 1 Sensor 2.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
6: AreaComputer and output circuits
EB: FaultThe specific fault in that area

What it means

P06EB means the engine control unit has judged the performance of the NOx sensor processor (the control electronics that read the NOx sensor and report to the ECU) for Bank 1 Sensor 2 to be faulty. Sensor 2 is normally the NOx sensor downstream of the SCR catalyst or NOx aftertreatment. The ECU saw signals from the processor that were implausible, out of range, unstable or not matching expected values. Exact sensor location and how the processor is packaged depend on the model and engine.

Symptoms

Engine warning light on
Exhaust fluid (SCR) or emissions system warning message on the dash
Reduced engine power or limp mode on some vehicles
Increased fuel consumption or poor running in some cases
Other NOx sensor or SCR efficiency codes stored alongside
Possible restart or inducement warning countdown on some diesels

Possible causes

Failing NOx sensor and processor unit (the processor is often built into the sensor assembly)likely
Damaged wiring, corrosion or poor connection in the sensor connector, including water ingresslikely
Low or poor-quality exhaust fluid affecting the sensor readings and the plausibility checkspossible
Exhaust leak near the sensor upstream of the sensor or contamination of the sensor tippossible
Supply voltage or earth problem affecting the processor, such as a weak battery or poor earthpossible
Communication fault on the data network between the processor and ECUrare
Faulty ECU or outdated software where the manufacturer has documented a faultrare

How to diagnose

Read all stored codes and freeze frame data, noting any other NOx, SCR, exhaust fluid or network codes and the conditions when it set.
Check for manufacturer service bulletins or known software issues for the specific model and engine.
Inspect the NOx sensor wiring and connector for damage, heat or chafing, corrosion, water and bent or loose pins.
Check the exhaust fluid level and quality, and look for related warnings.
Inspect the exhaust for leaks around the sensor and the SCR catalyst area, and check the sensor for contamination or damage.
Check battery condition, charging voltage and the sensor's supply and earth circuits with a multimeter.
With a suitable scan tool, view live NOx sensor data and compare it to expected values, such as engine-off readings and plausible readings at idle.
Check the data network communication for faults between the sensor processor and ECU, following the manufacturer's wiring diagram.

How to fix

Repair or replace damaged wiring, terminals or connectors, and seal out moisture.
Replace the NOx sensor and processor assembly if it is faulty, using the correct part for the vehicle.
Correct exhaust fluid level or quality problems as the manufacturer specifies.
Repair any exhaust leak affecting the sensor.
Fix supply voltage or earth faults, and replace a weak battery.
Apply a manufacturer software update only if it is a documented fix for this fault, then clear the codes and road test.

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but book it in soon as emissions control may be affected and some vehicles will reduce power or restrict restarts if the fault is not fixed. Heed any dash warnings or countdowns.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.