309B01001-2 Tohatsu CYLINDER HEAD

Table 1
Diagnostic Trouble Codes
J1939 Code CDL Code Code Description Comments
157-17 E398 (1) Low Fuel Rail Pressure The fuel rail pressure is below an acceptable level.
The code is logged.
The check engine light will illuminate.
Table 2
Associated Diagnostic Trouble Codes
J1939 Code CDL Code
157-3 1797-3
157-4 1797-4
5584-15 E390 (1)
5584-16 E390 (2)
1347-5 1779-5
1347-6 1779-6
1348-5 1780-5
1348-6 1780-6
5580-17 E198 (1)
5580-18 E198 (2) Troubleshooting Procedure
Complete the procedure in the order in which the steps are listed.
Table 3
Troubleshooting Test Steps Values Results
1. Check for Associated Codes
A. Establish communication between Cat® Electronic Technician (ET) and the Engine Electronic Control Module (ECM).
B. Download the "Warranty Report" from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes.
C. If any of the associated codes in Table 2 are logged, troubleshoot the codes before continuing with this procedure.
Associated Codes
Result: An associated code is active or logged.
Repair: Troubleshoot the associated codes before continuing with this procedure.
Result: An associated code is not active or logged.
Proceed to Test Step 2.
2. Inspect the Fuel System
A. Inspect the fuel system. Refer to Systems Operation/Testing and Adjusting, "Fuel System - Inspect" for inspection of the high-pressure fuel lines and the fuel rail.
B. Retorque the quill tubes. Tighten the nut for quill tube to a torque of 70 3 N m (52 2 lb ft). Refer to D&A, "Unit Injector - Remove and Install".
Fuel System Problems
Result: Problems were found with the fuel system.
Repair: Repair the components or replace the components that are damaged. Verify that the problem is resolved.
Result: Problems were not found with the fuel system.
Proceed to Test Step 3.
3. Check the Fuel Rail Sensor
A. Allow the engine to be OFF for 10 minutes.
B. Turn the keyswitch to the ON position, do not start the engine.
C. Connect to the Engine ECM using Cat ET.
D. Using Cat ET, check the status of the "Fuel Rail Pressure (absolute)".
Rail pressure less than 5,000 kPa (725 psi) Result: The pressure dropped below 5,000 kPa (725 psi) after the engine was shut off for 10 minutes.
Proceed to Test Step 4.
Result: The pressure did not drop below 5,000 kPa (725 psi) after the engine was shut off for 10 minutes.
Repair: Replace the fuel rail pressure sensor. If the problem has been corrected, return the unit to service.
4. Start the Engine
A. Try to start the engine.
Engine will Start Result: The engine will start.
Proceed to Test Step 5.
Result: The engine will not start.
Repair: Refer to Systems Operations/Testing and Adjusting, "Injector Bypass Fuel Flow"
Illustration 1 g03383455
Location of the "Fuel System Functional Test" in the "Diagnostic Service Test" menu
Illustration 2 g03383456
If an E398 Low Fuel Rail Pressure fault is active, the "Fuel System Functional Test – Pretest" will not be able to run. Uncheck the "Fuel System Functional Test – Pretest" box and proceed to the "Fuel System Functional Test"
Illustration 3 g06560958
Note: Engine fuel system high-pressure fuel return ratio calibration value will only be visible after the Fuel System Functional Test has completed. It will not be visible during the pre-test.
Table 4
Troubleshooting Test Steps Values Results
5. Perform the "Fuel System Functional Test"
A. Start the engine.
B. Connect to the Engine ECM using Cat ET.
C. Perform the "Fuel System Functional Test" in Cat ET. Cat ET will display an error message that indicates the problem. Follow the repair procedure for the error message. If the test aborts for an active diagnostic make sure to troubleshoot the code first.
If an E398 Low Fuel Rail Pressure fault is active, the "Fuel System Functional Test – Pretest" will not be able to run. Uncheck the box and proceed to the "Fuel System Functional Test".
Test Passed
Result: The test failed for an $1120 - Fuel Pump Not Timed Correctly
Repair: Remove the high-pressure fuel pump. Refer to Disassembly and Assembly for the correct procedures. Pin the engine to TDC. Time the pump and then reinstall the high-pressure fuel pump. Then, run the "Fuel System Functional Test" to verify that the pump is timed correctly.
Result: The test failed for an $111F Fuel Flow Too Low (Engine Fuel System High-Pressure Fuel Ratio Calibration Value) is 1.5 or above (Note: Requires the latest version of Cat ET). Refer to Illustration 3.
Repair: Perform "Injector Bypa