91553-ZW9-300 Honda BUSH (13X15X15) (Honda Code 7668239).

Probable Causes
Software
Inlet air restriction
Exhaust restriction
Sensor
Fuel injectors
Valve lash
Gear trainRecommended Actions
Table 1
Troubleshooting Test Steps Values Results
1. Ensure that the latest Flash File Software is Installed in the ECM
A. Connect Cat® Electronic Technician (ET) to the service tool connector.
B. Use Cat ET to verify that the correct flash file is being used.
Flash File
Result: The latest flash file is installed.
Proceed to Test Step 2.
Result: The latest flash file is not installed.
Repair: Perform the following procedure:
1. Download the latest flash file from SIS web.
2. Install the software into the ECM.
Refer to Troubleshooting, "ECM Software - Install" for additional information.
If the problem is not resolved, proceed to Test Step 2.
2. Check for a Restriction in the Inlet Air System
A. Check the air filter restriction indicator, if equipped. Refer to the Operation and Maintenance Manual.
B. Measure the inlet air restriction for each turbocharger. Refer to Troubleshooting, "Inlet Air Is Restricted" for additional information.
Restriction
Result: The inlet air restriction is OK.
Proceed to Test Step 3.
Result: The inlet air restriction is NOT OK. An imbalance in the system is discovered.
Repair: Repair or replace damaged inlet air system components. Equalize the inlet air restriction for each of the turbochargers.
If the problem is not resolved, proceed to Test Step 3.
3. Check for a Restriction in the Exhaust System
A. Visually inspect the exhaust for signs of restrictions. Visually inspect the DOC for restrictions.
Restriction
Result: There are no exhaust restrictions.
Proceed to Test Step 4.
Result: There are exhaust restrictions.
Repair: Repair or replace damaged exhaust system components.
Note: If the exhaust temperature in a cylinder varies more than 50° C (122° F) from the normal operating temperature, inspect the injector for damage.
If the problem is not resolved, proceed to Test Step 4.
4. Check for Proper Operation of the Intake Manifold Pressure Sensor
A. Connect Cat ET.
B. Use Cat ET to monitor following pressure:
- "Boost Pressure"
C. Ensure that the reading is steady and varies with engine speed and load.
D. Verify that the status of the "Intake Manifold Pressure" is 0 kPa (0 psi) when the engine is not running.
Sensor
Result: The intake manifold pressure sensor appears to be operating correctly.
Proceed to Test Step 5.
Result: There appears to be a problem with the intake manifold pressure sensor.
Repair: Replace the intake manifold pressure sensor.
If the problem is not resolved, proceed to Test Step 5.
5. Test the Fuel Injectors
A. Connect to Cat ET.
B. Use Cat ET to perform the following fuel injector test:
- "Cylinder Cutout Test"
Refer to "Troubleshooting""Cat ET Service Features" for additional information.
Test
Result: The test was successful.
Proceed to Test Step 6.
Result: The test was not successful.
Repair: A failed fuel injector has been detected. Perform the following procedure:
1. Release the pressure in the high-pressure rail by loosening the end plug on one of the last two fuel accumulators. Refer to Testing and Adjusting, "Fuel Rail Pressure - Release" for instructions on how to release the pressurized fuel.
2. Verify the "Fuel Rail Pressure" reading in Cat ET is 0 8 MPa (0 1160 psi) prior to servicing the fuel system.
3. Replace the affected injector.
Verify that the repair eliminated the problem.
6. Check the Valve Lash
Note: The valve lash can affect the performance of the engine.
Valve Lash
Result: The valve lash is OK.
Proceed to Test Step 7.
Result: The valve lash is NOT OK.
Repair: Refer to Testing and Adjusting, "Valve Lash - Adjust" for additional information.
If the problem is not resolved, proceed to Test Step 7.
7. Inspect the Gear Train
A. Check the following gear train for damage:
- Crankshaft gear
- Camshaft drive gear
B. Verify that the crankshaft and the camshaft drive gears are set with the proper orientation for engine timing.
Gear Train
Result: The gear train has excessive wear.
Repair: Repair or replace damaged gear train components. Refer to the Disassembly and Assembly manual and the Reuse and Salvage Guidelines manual for additional information.
Verify that the repair eliminated the problem.
If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).