SPOOL AS 2671626 - Caterpillar

Probable Causes
Diagnostic codes
ECM parameters
Throttle signal
Air intake and exhaust system
Fuel supply
Low compression (cylinder pressure)
Electronic unit injectors
Individual malfunctioning cylindersRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.
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 "Warranty Report" from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes.
Troubleshoot any active codes before continuing with this procedure.
   
Diagnostic codes
   
Result: There are active or logged codes.
Troubleshoot any codes before continuing with this procedure.
Result: There are no active or logged codes.
Proceed to Test Step 2.
   
2. ECM Parameters
A. Use the electronic service tool to verify that the correct engine parameters are being used. Refer to Troubleshooting, "System Configuration Parameters" and Troubleshooting, "Customer Configuration Parameters" for additional information.
   
Parameters
   
Result: The parameters are not configured correctly.
Correctly configure the parameters.
Verify that the configuration change eliminated the fault.
Result: The parameters are configured correctly.
Proceed to Test Step 3.
   
3. Throttle Signal
A. Use the electronic service tool and observe the signal for the throttle position sensor.
   
Parasitic loads
   
Result: The throttle does not reach the 100% raw position and the calibrated position.
For an analog throttle, refer to Troubleshooting, "Speed Control (Analog) - Test".
For a digital throttle, refer to Troubleshooting, "Speed Control (PWM) - Test".
Result: The throttle reaches the 100% raw position and the calibrated position.
Proceed to Test Step 4.
   
4. Air Intake and Exhaust System
A. Check the air filter restriction indicator, if equipped. Clean plugged air filters or replace plugged air filters. Refer to the Operation and Maintenance Manual.
B. Check the air inlet and exhaust system for restrictions and/or leaks.
   
Restrictions
   
Result: The air filter is plugged.
Clean or replace the air filter. Refer to the Operation and Maintenance Manual for