2871961 | Genuine Cummins® Differential Pressure Sensor ISX15

Threading: M8 x 1.25 x 25mm
Overall Length: 2-3/4"
Connector: Rectangular 3-Pin

1. Measure DPF soot buildup

The sensor tells the engine computer:

• How hard exhaust is pushing before the DPF

• How free-flowing it is after the DPF

The pressure difference directly shows how full of soot the DPF is.

2. Control DPF regeneration

Using the sensor data, the ECM decides:

• When to start regeneration

• How long regeneration should last

• When regeneration is complete

This prevents:

• Regenerating too early (wastes fuel)

• Regenerating too late (plugs the DPF)

3. Protect the engine & exhaust system

If restriction gets too high, the sensor helps the ECM:

• Reduce engine power (derate)

• Prevent turbo damage

• Avoid overheating the exhaust

4. Maintain emissions compliance

The sensor ensures:

• Soot is properly burned off

• Exhaust emissions stay within legal limits

• The vehicle meets environmental regulations

5. Alert the driver & store fault codes

The sensor allows the ECM to:

• Turn on the DPF or check engine light

• Store diagnostic trouble codes

• Tell technicians what’s wrong

Warning lights & messages

• DPF warning light

• Check Engine Light

• Messages like “Service Exhaust System” or “DPF Full”

Regeneration problems

• Regenerations happen too often (wastes fuel)

• Regeneration never completes

• Vehicle asks for forced/manual regeneration

• Strong exhaust smell during regens

Performance issues

• Reduced power / derate mode

• Limited vehicle speed

• Poor throttle response

• Lower fuel economy

Computer & diagnostic symptoms

• Fault codes related to:

  • Differential pressure signal too high or too low

  • Sensor range/performance

  • DPF efficiency errors caused by bad readings

• Scan tool shows pressure readings that don’t make sense

  • High pressure at idle

  • No change when revving the engine

Electrical symptoms

• Intermittent issues (comes and goes)

• Codes return immediately after clearing

• Scan tool sometimes can’t read the sensor