TERMINAL AS 9X6766 - Caterpillar

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Note: If the problem only occurs under certain conditions, test the engine under those conditions. Examples of certain conditions are high engine speed, full load, and engine operating temperature. Troubleshooting the symptoms under other conditions can give misleading results.
Table 1
Troubleshooting Test Steps Values Results
1. Check for Active Codes and Logged Codes
A. Establish communication between Cat Electronic Technician (ET) and the Electronic Control Module (ECM).
B. Certain event codes may derate engine power. Monitor the diagnostic codes on Cat ET. Check for active diagnostic codes and logged codes (intermittent problems).
Codes
Result: A code is active or logged.
Repair: Troubleshoot any codes before continuing with this procedure.
Result: A code is not active or logged.
If the problem is not resolved, proceed to Test Step 2.
2. Programmable Parameters
A. If the ECM has been replaced, compare the values on the engine information plate to the following parameters from Cat ET.
- FRC Offset
- Full Load Setting (FLS)
- Full Torque Setting (FTS
B. Determine the type of throttle that is used in the application.
C. Program any parameters that may be associated with the throttle.
D. Program any parameters that may be associated with this troubleshooting procedure.
Parameters
Result: The parameters were program correctly.
Proceed to Test Step 3.
Result: The parameters were not programmed correctly and the engine had poor performance.
Repair: Reprogram the parameters and verify that they were programmed correctly.
If the problem is not resolved, proceed to Test Step 3.
3. Check for Cold Mode Operation (if applicable)
During cold mode operation, condensation may be present and is normal.
A. Cold mode is activated whenever the engine coolant temperature falls below a predetermined value. Monitor the status screen on Cat ET in order to verify that the engine has exited cold mode. Observe the reading for coolant temperature on Cat ET.
Cold Mode
Result: The engine is not operating in cold mode.
Proceed to Test Step 4.
Result: The engine is operating in cold mode.
Repair: This is normal operation. Return the engine to service.
4. Inspect the Electrical Connections
A. Check the associated wiring for damage, abrasion, corrosion, and for incorrect attachment on the following connectors:
- ECM Connectors
- Customer Connector
Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
Connectors
Result: The connectors and wiring appear to be OK.
Proceed to Test Step 5.
Result: The connectors and wiring are NOT OK.
Repair: Repair the wiring and/or the connectors. Replace parts if necessary. Ensure that all of the seals are properly in place and ensure that the connectors are coupled.
If the problem is not resolved, proceed to Test Step 5.
5. Check for an Intermittent Throttle Signal
A. Monitor the status for "Throttle Position" on Cat ET.
B. Verify that the status for "Throttle Position" is stable and that the engine is able to reach high idle speed.
Throttle Signal
Result: The status for "Throttle Position" is stable.
Proceed to Test Step 6.
Result: The status for "Throttle Position" is not stable.
Repair: Make the necessary repairs. Refer to Troubleshooting, "Throttle Position Sensor Circuit - Test", "Throttle Switch Control - Test", and "Speed Control - Test".
If the problem is not resolved, proceed to Test Step 6.
6. Monitor the Decelerator Pedal
A. Monitor the decelerator