9L6721 PAN GP-OIL Caterpillar parts
3408
Rating:
Alternative (cross code) number:
CA9L6721
9L-6721
9L6721
CA9L6721
9L-6721
9L6721
Weight: 0.08 pounds 0 kg.
TRUCK ENGINE,
Compatible equipment models: 9L6721:
Information:
Probable Causes
Cold Mode
Active Engine Derates
Throttle Signal from the Throttle Position Sensor
Turbocharger outlet pressure sensor (intake manifold air), Rated fuel position and/or FRC fuel position
Fuel supply
Air inlet and exhaust system
Accessory equipmentRecommended Actions
Cold Mode
Use the ET in order to determine the status of Cold Mode. Cold Mode operation may cause the engine to run rough and the engine power may be limited. Cold Mode is displayed in the engine status box on a status screen of the Caterpillar Electronic Technician (Cat ET). The engine will remain in Cold Mode for the following conditions.
Coolant temperature is below 18 °C (64 °F).
The engine is not cranking.
The engine has been running less than 14 minutes.Active Engine Derate
If an active derate occurs, the warning lamp will flash. "Engine Derate" will appear in the first engine status box on any Cat ET status screen. Verify that the set points for "Derate" that are in the Programmable Monitoring System have been programmed to the values that are correct. Throttle Signal from the Throttle Position Sensor
Verify that the "Top Engine Limit" and "High Idle" are programmed to the values that are correct. Monitor the parameters for the throttle on Cat ET. Use Table 1 to monitor the parameters.
Table 1
Throttle Parameters    "Desired Engine Speed"    "Throttle Position"    
"Low Idle"     Programmed to "low idle"     0%    
"High Idle"     Programmed to "high idle"     100%     The "Desired Engine Speed" and the "Throttle Position" should increase linearly. Both parameters should increase steadily to the Programmed "high idle". The Desired Engine Speed and the Throttle Position should decrease linearly. Both parameters should decrease steadily to the Programmed "low idle". Refer to Troubleshooting, "Throttle Position Sensor Circuit - Test" for additional information.Turbocharger outlet pressure sensor (intake manifold air), Rated fuel position and/or FRC fuel position
Monitor "Fuel Position" and "Rated Fuel Limit" on the fourth Cat ET status screen. If "Fuel Position" does not equal "Rated Fuel Limit" then check air inlet manifold pressure.
Verify that there are no active diagnostic codes that are associated with the Turbocharger Outlet Pressure Sensor (intake manifold air) or the Atmospheric Pressure Sensor.
Monitor turbocharger outlet pressure on the second Cat ET status screen and Atmospheric Pressure for normal operation. Note: Atmospheric Pressure is not a default parameter on a Cat ET status screen. A new parameter screen must be set up in order to monitor the Atmospheric Pressure sensor.Fuel Supply
Check for active Event Codes. E053 Low Fuel Pressure Warning may be active.
Check the fuel lines for the following problems: restrictions, collapsed lines and pinched lines. If problems are found with the fuel lines, repair the lines and/or replace the lines.
Check the fuel tank for foreign objects which may block the fuel supply.
Check for air in the low pressure fuel supply system if any of the following procedures have been performed:
Replacement of the fuel filters
Service on the low pressure fuel supply circuit
Replacement of unit injectors
Purge air from the low pressure fuel supply circuit. Refer to Operation and Maintenance Manual, "Fuel System - Prime"
Cold Mode
Active Engine Derates
Throttle Signal from the Throttle Position Sensor
Turbocharger outlet pressure sensor (intake manifold air), Rated fuel position and/or FRC fuel position
Fuel supply
Air inlet and exhaust system
Accessory equipmentRecommended Actions
Cold Mode
Use the ET in order to determine the status of Cold Mode. Cold Mode operation may cause the engine to run rough and the engine power may be limited. Cold Mode is displayed in the engine status box on a status screen of the Caterpillar Electronic Technician (Cat ET). The engine will remain in Cold Mode for the following conditions.
Coolant temperature is below 18 °C (64 °F).
The engine is not cranking.
The engine has been running less than 14 minutes.Active Engine Derate
If an active derate occurs, the warning lamp will flash. "Engine Derate" will appear in the first engine status box on any Cat ET status screen. Verify that the set points for "Derate" that are in the Programmable Monitoring System have been programmed to the values that are correct. Throttle Signal from the Throttle Position Sensor
Verify that the "Top Engine Limit" and "High Idle" are programmed to the values that are correct. Monitor the parameters for the throttle on Cat ET. Use Table 1 to monitor the parameters.
Table 1
Throttle Parameters    "Desired Engine Speed"    "Throttle Position"    
"Low Idle"     Programmed to "low idle"     0%    
"High Idle"     Programmed to "high idle"     100%     The "Desired Engine Speed" and the "Throttle Position" should increase linearly. Both parameters should increase steadily to the Programmed "high idle". The Desired Engine Speed and the Throttle Position should decrease linearly. Both parameters should decrease steadily to the Programmed "low idle". Refer to Troubleshooting, "Throttle Position Sensor Circuit - Test" for additional information.Turbocharger outlet pressure sensor (intake manifold air), Rated fuel position and/or FRC fuel position
Monitor "Fuel Position" and "Rated Fuel Limit" on the fourth Cat ET status screen. If "Fuel Position" does not equal "Rated Fuel Limit" then check air inlet manifold pressure.
Verify that there are no active diagnostic codes that are associated with the Turbocharger Outlet Pressure Sensor (intake manifold air) or the Atmospheric Pressure Sensor.
Monitor turbocharger outlet pressure on the second Cat ET status screen and Atmospheric Pressure for normal operation. Note: Atmospheric Pressure is not a default parameter on a Cat ET status screen. A new parameter screen must be set up in order to monitor the Atmospheric Pressure sensor.Fuel Supply
Check for active Event Codes. E053 Low Fuel Pressure Warning may be active.
Check the fuel lines for the following problems: restrictions, collapsed lines and pinched lines. If problems are found with the fuel lines, repair the lines and/or replace the lines.
Check the fuel tank for foreign objects which may block the fuel supply.
Check for air in the low pressure fuel supply system if any of the following procedures have been performed:
Replacement of the fuel filters
Service on the low pressure fuel supply circuit
Replacement of unit injectors
Purge air from the low pressure fuel supply circuit. Refer to Operation and Maintenance Manual, "Fuel System - Prime"
Caterpillar SIS machinery equipment:
Caterpillar parts catalog:
Parts pan Caterpillar catalog:
4N1733
PAN GP-OIL
3408, 3408B, 3408C, 631D, 631E, 633D, 637D, 637E, 639D, 657E, 768C, 769C, 771C, 988B, G3408, G3408B, G3408C, PR-450, PR-450C
3408, 3408B, 3408C, 631D, 631E, 633D, 637D, 637E, 639D, 657E, 768C, 769C, 771C, 988B, G3408, G3408B, G3408C, PR-450, PR-450C
2W0477
PAN GP-OIL
3408, 3408C, 834B, 836, 988B, PM-565
3408, 3408C, 834B, 836, 988B, PM-565
6N9055
PAN-OIL
3408, 3408C, 637D, 657E, 834B, 988B, PM-565
3408, 3408C, 637D, 657E, 834B, 988B, PM-565
4N1729
PAN
3408, 631D, 633D, 637D
3408, 631D, 633D, 637D
9L6678
PAN-OIL
3408
3408
2883579
PAN GP-OIL
2470C, 553C, 953D, 963D, C6.6
2470C, 553C, 953D, 963D, C6.6
9Y3309
PAN GP-OIL
3612
3612
1345210
PAN GP-OIL
69D, 769C, 769D, 771D
69D, 769C, 769D, 771D
1985336
PAN GP-OIL
3014, 3024
3014, 3024
2873291
PAN GP-OIL
3126E, C7
3126E, C7
2308253
PAN GP-OIL
3054C, 3054E, TH210, TH215
3054C, 3054E, TH210, TH215
7W6210
PAN GP-OIL
416, 426, 428
416, 426, 428
2861954
PAN GP-OIL
C-9, C9, TH31-E61
C-9, C9, TH31-E61
1416135
PAN GP-OIL
M312, M315
M312, M315
2169551
PAN GP-OIL
3056E, M316C, M318C, M318C MH, M322C
3056E, M316C, M318C, M318C MH, M322C
1102941
PAN GP-OIL
3056
3056
2637247
PAN GP-OIL
3406C
3406C