Table 6
Troubleshooting Test Steps Values Results
1. Diagnostic Codes
Note: Certain diagnostic codes may cause poor performance.
A. Use the electronic service tool to check for active or logged di-
agnostic codes.
Engine Derate
or Diagnostic
Codes
Result: A diagnostic code is present.
Troubleshoot the diagnostic code. Refer to Troubleshoot-
ing, “Diagnostic Trouble Codes”.
Result: A diagnostic code is not present.
Proceed to Test Step 2.
2. Parameters in the Electronic Control Module (ECM)
A. Use the electronic service tool to verify that the correct parame-
ters are being used. Refer to Troubleshooting, “Configuration Pa-
rameters” for additional information.
Parameters Result: The parameters are not correct.
Input the correct parameters. Refer to Troubleshooting,
“Configuration Parameters” for additional information.
Result: The parameters are correct.
Proceed to Test Step 3.
3. Throttle Position Sensor/Throttle Switches
A. Turn the start switch to the ON position.
B. Run the engine until the speed is equal to the maximum no-load
speed.
C. Use the electronic service tool to make sure that the throttle is
set to reach the maximum no-load speed.
Electrical
connections
Result: The throttle response is not as expected.
If the maximum no-load speed cannot be obtained refer to
Troubleshooting, “Switch Circuits - Test (Throttle Switch)”
and Troubleshooting, “Mode Selection - Test”.
If the engine speed is erratic refer to Troubleshooting,
“Speed Control - Test”.
Result: All responses are normal.
Proceed to Test Step 4.
4. Air Intake and Exhaust System
A. Observe the engine warning lamp. Check for an air filter restric-
tion indicator, if equipped. Replace plugged air filters. Refer to the
Operation and Maintenance Manual.
B. Check the air inlet and exhaust system for restrictions and/or
leaks. Refer to Systems Operation/Testing and Adjusting, “Air Inlet
and Exhaust System - Inspect”.
Restrictions Result: There are restrictions in the air inlet or exhaust
system.
Make the necessary repairs, Refer to Systems Operation/
Testing and Adjusting, “Air Inlet and Exhaust System - In-
spect” for additional information.
Result: There are no restrictions in the air inlet or exhaust
system.
Proceed to Test Step 5.
5. Valve Lash
Note: The valve lash can affect the performance of the engine.
A. Check the valve lash. Refer to Systems Operation, Testing and
Adjusting, “Engine Valve Lash - Inspect”.
Valve lash Result: The valve lash is not correct.
Make any necessary repairs. Refer to Systems Operation,
Testing and Adjusting, “Engine Valve Lash - Inspect”.
Result: The valve lash is correct.
Proceed to Test Step 6.
(continued)
32 UENR0612
Symptom Troubleshooting
This document has been printed from SPI2. NOT FOR RESALE
To Next Page
Loading...
