GEAR 2K5123 - Caterpillar

Probable Causes
Diagnostic codes
Accessory equipment
Power mode control (if equipped)
Fuel supply
Low compression (cylinder pressure)
Electronic unit injectorsRecommended 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) . If necessary, refer to Troubleshooting, "Electronic Service Tools".
B. Check if any codes are active or logged.
Diagnostic code
Result: A code is active or logged.
Repair: Troubleshoot any codes before continuing with this procedure.
Result: A code is not active or logged.
Proceed to Test Step 2.
2. Accessory Equipment
A. Check all accessory equipment for faults that may create excessive load on the engine.
Accessories
Result: An engine accessory is creating an excessive load.
Repair: Repair or replace the engine accessory.
Result: An engine accessory is not creating an excessive load.
Proceed to Test Step 3.
3. Power Mode Control (If Equipped)
A. Check whether the power mode control is using the Cat data link or the CAN data link and then use the appropriate test. Refer to Troubleshooting, "Data Link - Test" or Troubleshooting, "CAN Data Link - Test".
B. Check the engine wiring harness for defects. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Power mode control
Result: There is a fault in the data link.
Repair: Repair the data link, as necessary.
Result: There is a wiring fault.
Repair: Repair or replace the wiring, as necessary.
Result: The data link and the wiring are OK.
Proceed to Test Step 4.
4. Fuel Supply
A. Ensure that the vent in the fuel cap is not filled with debris.
B. Ensure that the fuel supply valve (if equipped) is in the full OPEN position.
C. If the temperature is below 0 °C (32 °F), check for solidified fuel (wax).
D. Check the primary filter/water separator for water in the fuel.
E. Check for fuel supply lines that are restricted.
F. Replace the primary and secondary fuel filters.
G. Check the diesel fuel for contamination. Refer to Systems Operation,