Mercedes Sprinter Front NOX Sensor – Genuine OEM | NCV3 OM642 & OM651 BlueTec | #0009053503 (2012–2018)

A failed front NOx sensor on a NCV3 Sprinter disrupts the ECU's upstream nitrogen oxide reference — causing erratic AdBlue dosing, SCR efficiency fault codes, and the power restriction countdown that escalates with each subsequent cold start until the sensor is replaced. This is the Genuine Mercedes-Benz OEM front NOx sensor for NCV3 Sprinters equipped with the 3.0L OM642 or 2.1L OM651 BlueTec diesel engine, a direct replacement that restores accurate upstream NOx measurement and proper aftertreatment system control.

What This Part Does

The front NOx sensor is positioned in the exhaust stream between the DPF and the SCR catalyst — measuring nitrogen oxide levels after the diesel particulate filter but before AdBlue injection and SCR processing. The ECU uses this reading as the input to its AdBlue dosing calculation, commanding the DEF pump to deliver the precise quantity of fluid needed to reduce the incoming NOx load to within legal limits. The downstream sensor then verifies the conversion. When the upstream sensor drifts out of calibration, returns an implausible signal, or fails electrically, the ECU's dosing model loses its reference input — causing the system to over-dose, under-dose, log efficiency faults, and enter the countdown mode that restricts and eventually prohibits operation.

Common Symptoms of a Failing Front NOx Sensor

• Check engine light with fault codes related to upstream NOx sensor circuit or SCR efficiency
• Engine entering limp mode or emissions system power restriction
• AdBlue consumption that is abnormally high or low with no dosing system fault identified
• NOx or SCR efficiency fault codes that return after clearing
• AdBlue countdown warning in the instrument cluster

When to Replace

Replace when the sensor is confirmed faulty by XENTRY or a compatible scan tool with active upstream NOx fault codes. Always use OEM — aftermarket NOx sensors are known to produce signal drift that causes persistent faults even after installation. When replacing the front sensor, inspect the downstream sensor at the same time, as both operate as a system.

NCV3 BlueTec Specific — VIN Verification Required

This sensor fits NCV3 Sprinters with the 3.0L OM642 and 2.1L OM651 BlueTec diesel engines. It is not compatible with early 2010–2011 NCV3 Sprinters which use different NOx sensor part numbers, or VS30 Sprinters. Always verify sensor position, engine code, model year, and VIN before ordering. Contact us and we'll confirm fitment before you buy.

Fitment

• 2012–2018 Mercedes-Benz Sprinter 2500 – 3.0L OM642 / 2.1L OM651 BlueTec (NCV3/W906)
• 2012–2018 Mercedes-Benz Sprinter 3500 – 3.0L OM642 / 2.1L OM651 BlueTec (NCV3/W906)
• 2012–2018 Freightliner Sprinter 2500 / 3500 – BlueTec models

✔ Front (upstream/post-DPF/pre-SCR) position only
✔ BlueTec models only — always verify model year and VIN before ordering
✔ Always use OEM — aftermarket NOx sensors are known to cause persistent faults

Part Numbers

• Mercedes OEM: 0009053503 / A0009053503 / 000-905-35-03
• Cross-reference: 5WK96682D / A0065427218
• Manufacturer: Genuine Mercedes-Benz
• SKU: 0009053503OE