24V CAN Bus Auto NOx Sensor 2872947 2872947NX Compliance With EPA 2010

The 5WK96753 is a planar dual-cell limiting current type nitrogen oxide (NOx) sensor designed for 24V medium-duty and heavy-duty diesel engine exhaust aftertreatment systems equipped with Selective Catalytic Reduction (SCR). As an electrochemical sensor that continuously measures the concentration of nitrogen oxides and oxygen in the exhaust stream, it communicates with the engine control unit via digital CAN bus protocol, enabling precise SCR system control and regulatory compliance with Euro V, Euro VI, EPA 2010, China 5/6, and equivalent emission standards.

The sensor consists of a ceramic sensor element and an electronic control unit, forming a single integrated unit installed in the exhaust system. The sensor measures the NOx concentration, air/fuel ratio, and equilibrium oxygen partial pressure in the exhaust gas of combustion engines, and can be used for diesel engine SCR catalysts, NOx traps, closed-loop NOx control, and on-board diagnostics.

The sensor transmits the NOx value in the exhaust gas to the ECU in real time after normal operation. The ECU monitors whether the NOx value in the exhaust gas exceeds the standard through a set of NOx monitoring programs. Most engines equipped with SCR aftertreatment systems utilize two NOx sensors. The upstream sensor (pre-SCR) provides real-time feedback for the SCR control loop to precisely meter Diesel Exhaust Fluid injection. The downstream sensor (post-SCR) monitors treated exhaust to confirm emissions compliance. The specified mounting position of the NOx sensor is downstream of the NOx trap or upstream/downstream of the SCR catalyst.

Important: The 5WK96753 operates on a 24V system voltage. It is designed for commercial vehicle SCR applications including trucks, buses, and construction equipment. Always verify your vehicle‘s electrical system voltage before installation. Do not install on 12V systems.

The sensor features standardized electronics interface via CAN bus and is compatible with catalytic converters, ECUs, and engine management systems from all manufacturers. All electronic components are integrated into the sensor, with rapid self-diagnostics and high measurement accuracy.

The following part numbers are directly interchangeable with 5WK96753. When searching for a replacement, these numbers may appear on the original sensor label, in supplier catalogs, or in vehicle manufacturer documentation. Always verify physical connector type, cable length, and voltage rating before purchasing.

From multiple supplier sources, the following cross-references have been verified:

• 5WK96753B is a Cummins NOx sensor compatible with Cummins engine systems including B6.7, F3.8, ISB6.7, ISL9, ISX12, ISX15, L9, QSB3.3, and QSB6.7

• The 5WK96753 works for Cummins ISB 6.7L engines and replaces: 2872947, 4326869, 5WK9 6753

• A supplier cross-reference list for 5WK96753/2872947 lists it as a Cummins platform sensor with square 4-pin DC24V connection

• 4326869 is listed as the OEM substitute for 5WK96753

⚠️ Suffix and supersession caution: Different variants (5WK96753 vs. 5WK96753B) may indicate minor production revisions or calibration differences. The 5WK96753B variant is documented as a genuine Cummins-referenced part compatible with specific CM2350 engine management systems. Different suffixes may have distinct CAN message IDs or heater calibration parameters. Match the full alphanumeric string on your original sensor whenever possible. Do not rely solely on partial number matches.

The 5WK96753 NOx sensor is designed for 24V commercial vehicle electrical systems and is primarily used with diesel engines in medium-duty and heavy-duty applications. Based on cross-reference information and manufacturer documentation, this sensor is widely used across multiple diesel engine platforms.

This sensor is closely associated with heavy-duty diesel engines in commercial vehicle applications. The sensor is a critical component for engine emission control systems, particularly for engines equipped with SCR aftertreatment meeting Euro V / Euro VI / EPA 2010 emissions standards.

The 5WK96753B variant is specifically documented as compatible with the following engine systems:

Based on cross-reference information and supplier listings, the 5WK96753 is compatible with the following engine families:

The 5WK96753 is found in a wide range of 24V commercial vehicle applications:

• Heavy-duty trucks – long-haul and regional transport (Euro V / Euro VI / EPA 2010 compliance)

• Medium-duty trucks – delivery and utility vehicles

• Buses and coaches – public transportation with SCR aftertreatment

• Freightliner trucks – with Cummins ISB 6.7L engines

• Blue Bird buses – school and transit buses

• Ford trucks – heavy-duty diesel applications

• International vehicles – heavy-duty truck platforms

• Thomas Built Buses – school buses

• IC Corporation – bus applications

• Construction equipment – SCR-equipped diesel machinery

• Industrial equipment – diesel-powered industrial applications

• Marine diesel engines – auxiliary and propulsion applications

The 5WK96753 is designed for vehicles meeting:

• Euro V and Euro VI – European emissions standards

• EPA 2010 – North American heavy-duty emissions standards

• China 5 and China 6 – Asian market requirements

• Equivalent Tier standards for off-road equipment

Depending on the vehicle configuration, the 5WK96753 can be mounted in either of the following positions:

• Upstream position (pre-SCR) – Before the SCR catalyst, used for real-time feedback to control DEF dosing

• Downstream position (post-SCR / System Outlet) – After the SCR catalyst, used for emissions compliance verification

The sensor‘s specified mounting position is downstream of the NOx trap or upstream/downstream of the SCR catalyst.

Due to the diversity of commercial vehicle configurations, physical fitment alone does not guarantee proper function. To confirm compatibility:

1. Check your original sensor label – Match the full part number 5WK96753 or cross-references (4326869, 2872947, etc.)

2. Verify voltage – The 5WK96753 is a 24V sensor; confirm your vehicle electrical system is 24V

3. Count connector pins – Square 4-pin sealed connector type

4. Measure cable length – Approximately 600 mm (varies by application)

5. Check ECU compatibility – Some platforms require software adaptation after sensor replacement

6. Confirm thread size – M20 x 1.5 external thread

⚠️ Important note: Compatibility extends beyond physical fitment. The sensor must match the ECU‘s CAN communication protocol. Different vehicle manufacturers may use different calibration parameters even when the physical sensor appears identical. Always reference your original sensor part number or consult vehicle-specific documentation before purchasing.

A degraded or failed 5WK96753 NOx sensor will typically trigger one or more of the following symptoms. Early recognition can prevent secondary damage to the SCR catalyst, DEF injector, Diesel Exhaust Fluid system, or Diesel Particulate Filter. NOx sensor failures rank among the most frequent emissions system problems in modern diesel engines, and when they fail, the consequences can be immediate—check engine lights, power derates, and potential limp mode conditions that can affect uptime.

The most common first indicator is the illumination of the check engine light on your dashboard. The ECU detects inconsistent, missing, or out-of-range NOx data and triggers a fault code. A faulty NOx sensor often illuminates the vehicle’s check engine light.

Common codes associated with NOx sensor failure include:

When the ECU receives a NOx sensor module serial data message indicating an open signal circuit for greater than 3 seconds, codes such as P2200 or P229E are set. When the ECU receives a NOx sensor module serial data message indicating NOx concentration is less than -90 ppm for greater than 3 seconds, code P2202 is set.

When NOx readings become inconsistent or implausible, the ECU reacts to protect emissions systems by limiting torque and engine speed. Commercial vehicles may experience speed limitation or restricted RPM until the issue is resolved. Unaddressed NOx sensor faults trigger escalating restrictions, from warning lights to speed limits and, in severe cases, no-restart conditions. Failed sensors can trigger limp mode, DEF warnings, power restriction countdowns, or prevent restart.

When the NOx sensor is unable to maintain a reliable output, its signal quality will be set to “not reliable.” This can occur during fast transients and fast variations in NOx sensor measurement value. Too long a duration of unreliable sensor signal quality is considered an error. Faulty internal start-up behavior of the NOx sensor can cause the sensor to be evaluated as not reliable.

A faulty NOx sensor disrupts the ECU and SCR, triggering fault codes and leading to incorrect DEF dosing. False high NOx readings cause the SCR to over-dose DEF, resulting in rapid AdBlue depletion and potential crystallized injector. This is one of the most costly indirect symptoms.

A malfunctioning NOx sensor can cause the engine control unit to adjust operating parameters, leading to decreased fuel efficiency. Symptoms may include high fuel consumption and reduced fuel economy margins.

A failing NOx sensor can result in weak acceleration, low engine power output, and uneven acceleration patterns as the ECU compensates for inappropriate NOx readings.

Overdosing of DEF leads to ammonia slip (NH₃), which may be visible as white vapor with a sharp, pungent odor exiting the tailpipe.

If the internal heater fails (open circuit), the sensor never reaches operating temperature, and DTCs set immediately after cold start. If the heater is open-circuit or readings are stuck, replacement is recommended.

Before replacing the 5WK96753, perform these basic checks:

1. Visual inspection – Look for damaged cable insulation, chafing against chassis components, bent pins, or a melted/cracked connector

2. Check DTC status – Using a diagnostic scan tool, verify which codes are present and whether they are active or intermittent

3. Heater resistance test – Measure between heater positive and heater ground pins. An open circuit or short indicates internal failure

4. Voltage supply – With key on and engine off, verify 24V power at the sensor connector

5. CAN bus integrity – Check CAN High and CAN Low lines for proper termination

6. Live data review – Observe NOx readings; a fixed reading of 0 ppm or pegged at maximum without change points strongly suggests a faulty sensor

Contamination from oil consumption, fuel quality issues, or DEF system malfunctions often destroys replacement sensors. Always diagnose the root cause before replacement to avoid repeat failures. Always verify AdBlue quality and level, check for exhaust leaks upstream of the sensor, and confirm the sensor‘s heater current during warm-up.

Note: A recurring NOx sensor code may also be caused by an exhaust leak upstream of the sensor, poor DEF quality, a failed DEF injector, or a contaminated SCR catalyst. Perform a thorough system diagnosis before sensor replacement to avoid repeat failures.

When the SCR system is being repaired, replacing the NOx sensor may be necessary. The sensor should be replaced and reset/adapted using an appropriate diagnostic tool. Many ECUs require a NOx reset/adaptation and a short drive cycle to relearn new sensor values after replacement.

Purchasing the correct 5WK96753 NOx sensor and installing it properly is essential for reliable SCR performance and avoiding costly mistakes. Commercial vehicle operators should pay special attention to electrical compatibility, programming requirements, and installation procedures.

• Match the full printed number on your original sensor – 5WK96753 or confirmed cross-references (4326869, 2872947, etc.)

• Check suffix revision – 5WK96753 vs. 5WK96753B. The suffix B variant is documented for specific CM2350 engine management systems and may have different CAN message IDs or heater calibration parameters

• Avoid “universal fit” listings – The 5WK96753 is a specific digital device; generic sensors claiming to fit “all 24V diesels” are unlikely to communicate correctly with your ECU

• Check the original OE number before making payments to ensure correct product fitment

• Reputable supplier – Choose a supplier with documented quality control (IATF 16949 or ISO 9001 certification) and a minimum 12-month warranty

• Avoid used or “remanufactured” – NOx sensors degrade internally from heat and contamination. Used sensors almost always fail prematurely

• Price guideline – Authentic quality replacements typically range from $150 to $300 for aftermarket options. Genuine OEM-referenced parts may command higher prices ($389+ for 5WK96753B)

• Packaging – New sensors should be shipped in anti-static, moisture-proof packaging with a protective cap over the ceramic tip

• Manufacturer capability – Look for suppliers with independent R&D, IATF 16949 certification, strict QC systems, CE and E-mark certification

• Do not touch the ceramic sensing tip – Skin oils cause thermal shock cracking during the first heat-up cycle

• Inspect cable routing – Ensure the new cable follows the original path, using existing clips and standoffs. Avoid sharp bends or contact with moving parts

• Validate dew point strategy – Consider validating reasonable dew point strategy to efficiently avoid element cracking

• Clean the bung threads – Use a thread chaser (M20 x 1.5) to remove carbon buildup and rust before installation

• Remove protective cap only when ready – Keep the sensor clean by removing the protective cap immediately before installation

Follow this sequence for proper installation:

1. Prepare the mounting location – Allow the exhaust system to cool before removal. Wear heat-resistant gloves and eye protection

2. Remove the old sensor – Carefully remove the faulty sensor from the exhaust bung

3. Inspect the vehicle connector – Ensure the mating connector is dry, clean, and free from corrosion

4. Remove protective cap – Immediately before installation, remove the protective cover from the sensor probe

5. Install the probe – Insert the sensor probe into the exhaust bung. Hand-tighten while holding the sensor body to prevent cable twisting

6. Torque properly – CRITICAL: Follow OEM torque specifications. Typical torque for M20 x 1.5 threads: 40–60 Nm (50 Nm ± 10 Nm). Torque specifications are critical as over-tightening cracks exhaust bungs while under-tightening causes leaks

7. Connect the harness – Connect the mating 4-pin connector to the sensor. Ensure the connector interior is clean and dry

8. Secure the cable – Use original routing clips and standoffs to secure the harness away from heat sources and moving parts

A new NOx sensor will NOT function correctly until the ECU learns its baseline values and performs a plausibility check. This is not optional. Many returns are caused by skipped adaptation, not a defective part.

Why adaptation is necessary: Engine Control Units continuously learn and adapt to sensor degradation over time. Installing a fresh component without resetting these learned values leaves your ECU operating on outdated, skewed data. Unless you explicitly instruct the ECU to erase its old memory and relearn the new baseline, the system will remain in a fault state.

What DOES NOT work: Attempting to clear deep-level adaptation memory by disconnecting the battery is ineffective on modern emissions systems and often triggers secondary Battery Management System faults.

What DOES work:

1. Install the sensor and securely connect the wiring harness

2. Connect a professional diagnostic scan tool capable of commercial vehicle diagnostics (SAE J1939 compatible)

3. Clear all existing DTCs – Use the diagnostic tool to clear all existing fault codes

4. Perform “NOx sensor reset / adaptation / teach-in” – This function is typically found under “Special functions,” “SCR system,” or “Aftertreatment service” in diagnostic software

5. Reset SCR learned values (if available) – This clears previously stored efficiency values from the old sensor

6. Drive cycle – Complete a 15–20 minute mixed driving cycle at operating temperature with varying engine loads

7. Verify readiness – After the drive cycle, check for any returning DTCs. Monitor live NOx data: it should fluctuate logically (higher readings under heavy load, lower readings at idle)

Software calibration is mandatory. A physical NOx sensor replacement must be paired with an ECU adaptation or reset to clear permanent fault codes and restore SCR efficiency.

Without proper adaptation, you may still see DTCs (e.g., P2200, P229E) even with a brand new sensor. Many returns are caused by skipped adaptation, not a defective part.

• Wiring harness condition: Commercial vehicles operate in harsh environments (vibration, heat, moisture, road salt). Inspect the full harness length for chafing, corrosion at connectors, and damaged insulation before condemning the sensor

• SCR system health: A recurring NOx sensor code may indicate a failed SCR catalyst, DEF quality issues, or a clogged DEF injector. These should be diagnosed before replacing the sensor a second time

• Multiple sensor positions: Many modern diesel engines use two NOx sensors. Verify which position requires replacement. Sensors cannot be interchanged randomly; each sensor has a unique CAN identification number corresponding to its specific location

• ECU software updates: In some cases, a recurring NOx sensor issue may be addressed by an ECU software update rather than repeated sensor replacement

• SCR efficiency testing: A standard stationary DPF regeneration is rarely sufficient for validation. An SCR efficiency test and verifying upstream/downstream PPM deltas are required

• In regions with mandatory emissions testing (EU, California, China, Australia, Brazil), a non-functioning NOx sensor will cause the MIL to illuminate, resulting in automatic inspection failure

• It is illegal to defeat, delete, or simulate the NOx sensor signal in any on-road vehicle. Always replace with a fully functional sensor

• Commercial fleets subject to emissions auditing must maintain properly functioning SCR systems, including accurate NOx sensing

• Progressive derate system: Unaddressed NOx sensor faults trigger escalating restrictions, from warning lights to 5 mph speed limits and no-restart conditions. Address NOx faults promptly to avoid catalyst degradation

• Before purchasing, confirm the supplier offers a return or exchange for compatibility errors

• Keep your original sensor until the new one is confirmed working – it serves as the ultimate reference for part number and fitment

• Request a data sheet or installation guide that includes pinout and adaptation steps if available

• Most reputable suppliers offer a 12-month warranty against manufacturing defects

The NOx Sensor 5WK96753 is a critical emissions aftertreatment component for 24V medium-duty and heavy-duty diesel commercial vehicles. It provides real-time NOx and O₂ measurement to the ECU for precise SCR control, enabling compliance with Euro V / Euro VI / EPA 2010 emission standards.

Key cross-references: 4326869, 4326869RX, 2872947, 2872947NX, 2872947RX, 5WK96753B, A2C89570700, A2C91703500, A2C95992900

Compatible engines include: B6.7, ISB6.7, ISL9, L9, ISX12, ISX15, QSB3.3, QSB6.7, F3.8, and other compatible diesel platforms with CM2350, CM2450, CM2250, CM850, and CM2850 engine management systems.

Key technical specifications:

• Supply voltage: 24V DC

• Communication: Digital CAN bus (SAE J1939)

• NOx measuring range: 0 – 3000 ppm

• Operating gas temperature: 100°C – 800°C

• Connector: Square 4-pin sealed

• Thread: M20 x 1.5

• Torque specification: 40–60 Nm

Installation requirements:

• Do not apply anti-seize to threads

• Do not touch ceramic sensing element

• Validate dew point strategy to avoid element cracking

• Professional installation and mandatory ECU adaptation required after replacement

• Perform root cause diagnosis before replacement (exhaust leaks, DEF quality, oil contamination)

CRITICAL NOTE – ECU ADAPTATION IS MANDATORY: A physical NOx sensor replacement must be paired with an ECU adaptation or reset to clear permanent fault codes and restore SCR efficiency. Disconnecting the battery will NOT work. Without proper adaptation, you will still see DTCs (P2200, P229E) even with a brand new sensor. Software calibration is mandatory.

Proper selection (matching part number and cross-references), confirmation of 24V system voltage, careful installation using correct torque (40–60 Nm), and mandatory ECU adaptation ensure full emissions compliance, optimal fuel economy, and reliable SCR system performance. Use this guide to confidently purchase and replace a failed 5WK96753 NOx sensor without compatibility issues or repeat failures.

For further technical support, refer to your engine or vehicle manufacturer‘s service documentation or consult a qualified diesel emissions specialist.