3406E, C-10, C-12, C-15, C-16 and C-18 On-highway Engines Caterpillar

Probable Causes

The probable root causes are listed in order below:

• Air Inlet System or Exhaust System

• Valve Lash

• Electronic Unit Injector

• Boost Pressure Sensor

• Atmospheric Pressure Sensor

• Electronic System problem

• Personality Module

Recommended Actions

Perform the following diagnostic procedures in order:

1. Check the Air Inlet System for restrictions or leakage. Check the Exhaust System for restrictions or leakage. Refer to Testing and Adjusting, "Air Inlet and Exhaust System - Inspect".

2. Check the valve lash. Refer to Testing and Adjusting, "Engine Valve Lash - Inspect/Adjust".

3. Check the Electronic Unit Injector.

   1. Ensure that the Electronic Unit Injector Connector (J300/P300) is fully connected and ensure that the Electronic Unit Injector Connector (J300/P300) is free of corrosion.

   2. Ensure that the ECM Engine Harness Connector (J2/P2) is fully connected and ensure that the Engine Harness Connector (J2/P2) is free of corrosion.

   3. Connect an Electronic Service Tool. Use the Cylinder Cutout Test. Access the Cylinder Cutout Test by selecting the "Diagnostic Menu" and the "Diagnostics Test Menu". Run the Cylinder Cutout Test in order to disable each cylinder. Disabling each cylinder allows the technician to isolate the misfiring cylinders.

      If the misfiring cylinder can be isolated to a specific cylinder, refer to Troubleshooting, "Injector Solenoid Circuit - Test".

4. Check the Boost Pressure Sensor and the Atmospheric Pressure Sensor.

   1. Connect an Electronic Service Tool.

   2. While the problem is occurring, check for Diagnostic Codes that are related to the Boost Pressure Sensor and the Atmospheric Pressure Sensor. If a Diagnostic Code is found, refer to Troubleshooting, "Engine Pressure Sensor Open or Short Circuit - Test".

5. Check for an Electronic System problem.

   1. Connect an Electronic Service Tool.

   2. Monitor the Fuel Position, the Rated Fuel Limit and the FRC Fuel Limit.

      While the vehicle is operating under full load, the parameters should meet the following conditions:

      • The Fuel Position is equal to the Rated Fuel Limit.

      • The Fuel Position is less than the FRC Fuel Limit.

      If the Fuel Position is equal to the Rated Fuel Limit and the Fuel Position is less than the FRC Fuel Limit, the Electronics are operating correctly. Go to Step 7.

6. If the Fuel Position is not equal to the Rated Fuel Limit and/or the Fuel Position is not less than the FRC Fuel Limit, perform the following tests in order:

   1. Connect an Electronic Service Tool.

   2. When the engine is OFF, turn the Ignition Key Switch to the ON position. Check the boost pressure on an Electronic Service Tool Status Screen.

      When the engine is OFF, the boost pressure should be 0 kPa (0 psi).

   3. Monitor the status of the Accelerator Pedal Position Sensor. Operate the engine at high idle with the vehicle in Neutral.

      If the engine can not reach the programmed "Top Engine Limit", check the Accelerator Pedal Position Duty Cycle in order to ensure that the Accelerator Pedal Position Duty Cycle is within calibration (75 to 90 Percent at high idle).

      If the accelerator pedal position is unstable, check the Accelerator Pedal Position Duty Cycle. Check the Accelerator Pedal Position Duty Cycle by slowly operating the accelerator pedal in order to verify that the Accelerator Pedal Position Sensor is within calibration. The Accelerator Pedal Position Sensor is within calibration when both of the following conditions are met:

      • 10 to 22 percent at low idle

      • 75 to 90 percent at high idle

      Also, ensure that the duty cycle changes as the pedal position changes.

      If a problem with the Accelerator Pedal Position Sensor is suspected, refer to Troubleshooting, "Accelerator Pedal (Throttle) Position Sensor Circuit - Test".

      Note: If the engine exceeds the Top Engine Limit, the "Top Engine Limit with Droop" is programmed to YES.

7. Monitor the vehicle speed signal. Ensure the accuracy of the vehicle speed signal by comparing the vehicle speed signal to the actual vehicle speed.

   If the vehicle speed is greater than the VSL, the Power is limited. If a problem is discovered, refer to Troubleshooting, "Vehicle Speed Circuit - Test".

8. Check the "Power train Data Link". Ensure that the SAE J1922 or the SAE J1939 Power train Data Link is not limiting the power.

   1. Connect an Electronic Service Tool.

   2. Monitor the "Power train Data Link" Status screen while the vehicle is experiencing problems.

      If the "Power train Data Link" Status screen indicates that the "Power train Data Link" is limiting the power or the rpm, verify that this is not normal operation. If this is not normal operation, refer to the vehicle OEM for repairs.

9. Check the ECM or the Personality Module.

   1. Connect an Electronic Service Tool.

   2. Verify that the correct Personality Module has been installed.

      Refer to Troubleshooting, "ECM Memory - Test".