68575279AA | Genuine Cummins® Engine Controller Module 2023-2024 Ram

The ECM constantly monitors sensors throughout the engine and makes adjustments to keep everything running efficiently. Its main jobs include:

1. Controlling fuel injection
   It decides how much fuel to send to the engine based on conditions like throttle position, air temperature, and engine load.

2. Controlling ignition timing
   It determines when the spark plugs should fire for the best power and fuel efficiency.

3. Managing air–fuel mixture
   It ensures the engine gets the right amount of air and fuel for smooth operation.

4. Monitoring emissions
   It adjusts the engine to reduce pollution and meet emission standards.

5. Running diagnostic checks
   If something goes wrong, the ECM stores trouble codes and turns on the Check Engine Light.

6. Working with other systems
   It communicates with the transmission control module, ABS, traction control, etc.

1. Check Engine Light Stays On or Comes Back Repeatedly

If the ECM is malfunctioning, it may trigger random or incorrect trouble codes—even after repairs.

2. Engine Misfires or Runs Rough

A failing ECM may send wrong signals to the injectors or ignition system, causing misfires, shaking, or rough idling.

3. Poor Fuel Economy

Because the ECM controls the air–fuel mixture, a bad module can make the engine burn more fuel than normal.

4. Difficulty Starting or No Start

If the ECM fails completely, the engine may crank but not start—because fuel injection and spark timing are not being managed.

5. Engine Stalling or Cutting Out

Intermittent ECM issues can cause the engine to randomly stall while driving or idling.

6. Loss of Power or Limp Mode

The ECM may restrict engine performance to protect the vehicle, causing sluggish acceleration.

7. Transmission Shifting Problems

In many cars, the ECM communicates with the transmission control module. A bad ECM can cause hard shifts or wrong gear timing.

8. Incorrect or Strange Sensor Readings

If the ECM can’t process sensor data correctly, you might see:

• incorrect temperature readings

• fluctuating RPM

• wrong fuel trim values