C1.7 and C2.2 Industrial Engine Caterpillar

Engine Top Speed Is Not Obtained

Usage:

C1.7 G34

Note: If this fault occurs only under load, refer to Troubleshooting, "Acceleration Is Poor or Throttle Response Is Poor".

Probable Causes

Diagnostic codes
Fuel pump calibration
Accessory and/or parasitic loads
Throttle signal for the throttle position sensor (if equipped)
Throttle signal for the CAN data link (if equipped)
Air intake and exhaust system
Fuel supply
Low compression (cylinder pressure)
Electronic unit injectors
Individual malfunctioning cylinders

Table 1
Troubleshooting Test Steps	Values	Results
1. Diagnostic Codes A. Establish communication between the electronic service tool and the Electronic Control Module (ECM). Refer to Troubleshooting, "Electronic Service Tools", if necessary. B. Download the Product Status Report before troubleshooting or clearing any diagnostic codes. Note: The downloaded information will be required by the DSN if troubleshooting assistance is needed. C. Use the electronic service tool to check for active or logged codes.	Diagnostic codes	Result: There are active or logged codes. Repair: Troubleshoot any codes before continuing with this procedure. Result: There are no active or logged codes. Proceed to Test Step 2.
2. Fuel Pump Calibration A. Establish communication between the electronic service tool and the Electronic Control Module (ECM). Refer to Troubleshooting, "Electronic Service Tools", if necessary. B. Perform the "Fuel Pump Learn" procedure.	Fuel pump calibration	Result: The symptom is eliminated. Repair: Return the unit to service. Result: The symptom is still present. Proceed to Test Step 3.
3. Accessory and/or Parasitic Loads A. Check all accessory equipment for problems that may create excessive load on the engine. B. Check for any excess parasitic load on the engine.	Parasitic loads	Result: There is an excessive load on the engine. Repair: Diagnose and repair the fault. Verify that the repair eliminated the fault. Result: There is not an excessive load on the engine. Proceed to Test Step 4.
4. Throttle Signal for the Throttle Position Sensor (If Equipped) A. Use the electronic service tool and observe the signal for the throttle position sensor. Make sure that the throttle reaches the 100% raw position and the calibrated position.	Analog throttle input	Result: The throttle signal is erratic or does not reach the 100% raw position or the calibrated position. Repair: Refer to Troubleshooting, "Speed Control (Analog) - Test". Result: The throttle signal is OK. Proceed to Test Step 5.
5. Throttle Signal for the CAN Data Link (If Equipped) A. Use the electronic service tool and observe the signal for the throttle position sensor. Make sure that the throttle reaches the 100% raw position and the calibrated position.	CAN data link	Result: The throttle signal is erratic or does not reach the 100% raw position or the calibrated position. Repair: Refer to Troubleshooting, "CAN Data Link - Test". Result: The throttle signal is OK. Proceed to Test Step 6.
6. Air Intake and Exhaust System A. Check the air filter restriction indicator, if equipped. B. Check the air inlet and exhaust system for restrictions and/or leaks.	Restrictions	Result: The air filter is plugged. Repair: Clean or replace the air filter. Refer to the Operation and Maintenance Manual for further information. Result: There are restrictions in the air inlet or exhaust system. Repair: Make the necessary repairs, Verify that the repair eliminated the fault. Result: There are no restrictions in the air inlet or exhaust system. Proceed to Test Step 7.

Contact with high pressure fuel may cause fluid penetration and burn hazards. High pressure fuel spray may cause a fire hazard. Failure to follow these inspection, maintenance and service instructions may cause personal injury or death.

Show/hide table

NOTICE

Contact with high-pressure fuel may cause personal injury or death. Wait 10 minutes after the engine has stopped to allow fuel pressure to purge before any service or repair is performed on the engine fuel lines.

Show/hide table

Table 2
Troubleshooting Test Steps	Values	Results
7. Fuel Supply A. Check for leaks from the high-pressure fuel lines. B. Ensure that the vent in the fuel cap is not filled with debris. C. Ensure that the fuel supply valve (if equipped) is in the full OPEN position. D. If the temperature is below 0 °C (32 °F), check for solidified fuel (wax). E. Check the filter/water separator for water in the fuel. F. Check for fuel supply lines that are restricted. G. Replace the in-line fuel filter that is installed upstream of the Electric Fuel Lift Pump (EFLP). H. Replace the fuel filter. I. Check the diesel fuel for contamination. Refer to Systems Operation, Testing, and Adjusting, "Fuel Quality - Test". J. Check for air in the fuel system. Refer to Systems Operation, Testing, and Adjusting, "Air in Fuel - Test".	Fuel system	Result: There is a leak from a high-pressure fuel line. Repair: Replace the high-pressure fuel line. Refer to Disassembly and Assembly, "Fuel injection lines - Remove" and Disassembly and Assembly, "Fuel injection lines - Install". Result: The vent in the fuel cap is blocked. Repair: Install a replacement fuel cap. Result: The fuel contains solidified wax. Repair: Replace the fuel with fuel of the correct specification for the ambient conditions. Result: There are fuel supply lines that are restricted. Repair: Replace any damaged or restricted fuel lines. Replace the fuel filter. Refer to the Operation and Maintenance Manual for further information. Result: There is air in the fuel system. Repair: Prime the fuel system. Refer to Systems Operation, Testing, and Adjusting, "Fuel System - Prime". Result: The diesel fuel is contaminated. Repair: Drain the fuel tank and the fuel system. Replace the fuel filter. Refer to the Operation and Maintenance Manual for further information. Fill and prime the fuel system with fuel of the correct specification. Refer to Systems Operation, Testing, and Adjusting, "Fuel System - Prime". Result: The fuel supply is OK. Proceed to Test Step 8.
8. Low Compression (Cylinder Pressure) A. Perform a compression test. Refer to Systems Operation, Testing, and Adjusting, "Compression - Test".	Cylinder compression	Result: The results of the compression test are outside the specifications. Repair: Investigate the cause and rectify any faults. Note: Possible causes of low compression are shown in the following list: · Loose glow plugs · Faulty piston · Faulty piston rings · Worn cylinder bores · Worn valves · Faulty cylinder head gasket · Damaged cylinder head Result: The results of the compression test are OK. Proceed to Test Step 9.
9. Electronic Unit Injectors A. Use the electronic service tool to perform the automatic "Cylinder Cut Out Test". Note: If the compression test that was performed in Test Step 8 was satisfactory, the "Cylinder Cut Out Test" will identify any faulty injectors.	Electronic Unit Injectors	Result: A faulty injector is indicated. Repair: Remove any faulty electronic unit injectors. Refer to Disassembly and Assembly, "Electronic Unit Injector - Remove". Install new electronic unit injectors. Refer to Disassembly and Assembly, "Electronic Unit Injector - Install". Repeat the automatic "Cylinder Cut Out Test". If the fault is still apparent, remove the replacement electronic unit injector and install the original electronic unit injector. Refer to Disassembly and Assembly, "Electronic Unit Injector - Remove" and Disassembly and Assembly, "Electronic Unit Injector - Install". Result: All injectors are OK. Proceed to Test Step 10.
10. Individual Malfunctioning Cylinders A. With the engine speed at a fast idle, use the electronic service tool to perform the manual "Cylinder Cut Out Test". As each cylinder is cut out, listen for a change in the sound from the engine. When a cylinder is cut out, there should be a noticeable change in the sound of the engine. If a change in the sound of the engine is not noted, the isolated cylinder is not operating under normal conditions. If the isolation of a cylinder results in a change in the sound that is less noticeable, the cylinder may be operating below normal performance.	Cylinders	Result: The test indicates a faulty cylinder. Repair: Investigate the cause of the fault on any cylinder that is not operating. Investigate the cause of the fault on any cylinder that is operating below normal performance. Result: The test indicates that all cylinders are OK. Contact the Dealer Solutions Network (DSN).