Detroit Diesel GHG17 Low Pressure Fuel System – Measuring Fuel Pressure with Fuel System Integrity Check

This procedure outlines how to measure and record fuel pressure in the low-pressure side of the Detroit Diesel GHG17 fuel system using the Fuel System Integrity Check. It applies to both KM59 Gen 1 and KM63 Gen 2 dual filter fuel systems.

Preparation:

DDDL 8.19 2024
Nexiq USB Link 2 Adapter

Procedure:

1. Tool Installation for KM59 Gen 1 Systems:
   • KM59 Gen 1 Only: Install tool number W470589099100 to test the fuel pressure by inserting it into the high-pressure flange. Follow the installation instructions provided in Tool Letter 11 TL-9.
2. Tool Installation for KM59 Gen 1 and KM63 Gen 2 Systems:
   • Install tool number W470589149100 filter cap with the test fitting.
   • Check the pre-filter at this stage. If clogged, clean or replace the filter as necessary. Refer to Tool Letter 12 TL-8 for installation instructions.
3. Connect DDDL and Prepare for Testing:
   • Connect the DDDL to the vehicle and turn the ignition on.
   • Navigate to Service Routines and open the Fuel System Integrity Check tab in the DDDL.
4. Run the Fuel System Integrity Check:
   • Start the Fuel System Integrity Check routine in the DDDL and follow the on-screen instructions.
5. Monitor Fuel Pressures:
   • While the routine is running, monitor the following fuel pressures:
     • Low Pressure Pump Outlet (LPPO) fuel pressure
     • Fuel compensation pressure
     • Low Pressure Pump Inlet (LPPI) fuel pressure
       
       
6. Record LPPI Fuel Pressure:
   • Add the LPPI fuel pressure value as a user event in the DDDL log file. Press CTRL, SHIFT, and SPACEBAR simultaneously to capture the pressure value from the gauge.
     
7. Compare Fuel Pressure:
   • Compare the recorded fuel pressure value to the normal fuel pressure to assess the system’s performance.
8. Complete Troubleshooting:
   • After comparing the values, return to your original troubleshooting process.
   • Once troubleshooting is complete, remove any special tools used from the engine.

Notes:

• KM59 Gen 1 Systems: The return line is attached to the KM59 GEN1 fuel filter module using a banjo bolt.
• KM63 Gen 2 Systems: The return line is attached to the KM63 GEN2 fuel filter module using a mounting plate connected to the PLV return line.

This procedure will provide electronic results that can be viewed in the DDDL log file, aiding in accurate diagnosis and troubleshooting of the fuel system.