Probable Causes
The probable root causes are listed in order below:
• Diagnostic codes
• Intake valve actuation system
• Cold mode
• Customer specified parameters (normal operation)
• Individual malfunctioning cylinder
• Power train Data Link
• Torque limit switch
Recommended Actions
Diagnostic Codes
1. Connect the Caterpillar Electronic Technician (Cat ET) to the data link connector.
2. Check for active codes and/or logged codes.
Troubleshoot any codes that are present before continuing with this procedure.
Note: Certain diagnostic codes may cause poor performance.
Intake Valve Actuation System
1. Start the engine.
2. Monitor the status screens on Cat ET.
3. Check for an “Intake Vlave System Starting” flag at the top left of any status screen.
Note: The engine will not receive full power until the “Intake Vlave System Starting” flag becomes inactive.
Cold Mode
1. Start the engine.
2. Monitor the status screens on Cat ET.
3. Check for a “Cold Mode” flag at the top of any status screen.
Note: The engine will not receive full power until the “Cold Mode” flag becomes inactive.
Customer Specified Parameters
1. Verify that the complaint is not normal operation (programmed parameter).
2. Access the “Configuration” screen on Cat ET.
3. Check the following parameters:
• “Lower Gears Engine RPM Limit”
• “Intermediate Gears Engine RPM Limit”
• “Gear Down Protction Engine RPM Limit”
4. Set each parameter to the parameter’s maximum value one at a time and determine whether the problem is corrected.
Individual Malfunctioning Cylinder
1. Ensure that the front valve cover connector and the rear valve cover connector are fully
connected and ensure that the valve cover connectors are free of corrosion.
2. Ensure that the J2/P2 ECM connector is fully connected and ensure that the ECM connector is free of corrosion.
3. Use the “Cylinder Cutout Test”. Access the “Cylinder Cutout Test” by selecting the “Diagnostics Test” under the “Diagnostic” 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”.
Power train Data Link
1. Ensure that the power train data link is not limiting the power.
2. Monitor the “Powertrain Data Link” status screen while the vehicle is experiencing problems.
If the “Powertrain Data Link” status screen indicates that the “Powertrain 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.
Torque Limit Switch
1. Check the setting for the customer parameter for the “Torque Limit”.
If the “Torque Limit” is programmed below 3400 N·m (2500 lb ft), check the status screen for the Torque Limit Switch. Ensure that the status screen indicates that the torque limit switch is OFF. If the status of the torque limit switch is ON and a “Torque Limit” is programmed, the system is operating correctly. If the switch that is connected to this signal input is not switching ON and switching OFF, refer to Troubleshooting, “PTO Switch Circuit – Test”.
