Series 60 DDEC V Troubleshooting – Section 51.2 Troubleshooting Flash Code 48, PID 94, 412, 411, 351, 404/FMI 1

Section 51.2
Troubleshooting Flash Code 48, PID 94, 412, 411, 351, 404/FMI 1

This condition is normally associated with a restriction in the fuel supply system (currently not used):‪

• Plugged fuel filter
• Low fuel supply

Note: Not all engines use a fuel pressure sensor.

For gas engines, code 48 indicates that the air inlet pressure has dropped below a calibration limit.‪

Flash Code 48 is also used to identify the EGR Delta-Pressure, or EGR temperature is below programmed limits. This condition is typically due to:‪

• EGR valve not opening completely
• EGR valve not opening at all – leaking CAC.
• Leaking EGR piping/hoses.

Flash Code 48 also indicates the exhaust gas temperature fell below calibrated limits, or EGR Delta-Pressure fell below calibrated limits. Possible causes include: ‪

• EGR valve not opening
• EGR valve not opening fully
• Leaking CAC

Flash Code 48 also indicates the TCI (Turbo Compressor Inlet) or TCO (Turbo Compressor Outlet) temperature fell below the calibrated limits. Possible causes include: ‪

• Leaking CAC
• Leaking inlet piping
• EGR valve not opening properly

Fuel Pressure code is logged as a result of a mechanical fault. Check for reasons for low fuel pressure. Refer to appropriate service manual, section 5. ‪

For all EGR related codes, always perform Exhaust Gas Recirculation System Basic Checks . Refer to "20.18 Exhaust Gas Recirculation System Basic Checks for Series 60 Engines" .‪

Then, perform the following steps to troubleshoot code 48: ‪

Section 51.2.1
Check for Other Codes

Perform the following steps to check for other codes:‪

1. Turn ignition ON.
2. Plug in diagnostic tool.
3. Read active codes.
   1. If code 39 and others display, service the other codes first.
   2. If code 39 did not display, refer to "51.2.2 Vehicle Air Test" .

Section 51.2.2
Vehicle Air Test

The vehicle air test should have been performed during Exhaust Gas Recirculation System Basic Checks . Refer to "20.18 Exhaust Gas Recirculation System Basic Checks for Series 60 Engines" . If the test was not performed, refer to proper section and perform all steps.‪

1. If the vehicle air system failed the test, resolve low vehicle air pressure.
2. If the vehicle air system passed the test, replace the EGR valve and refer to "51.2.2.1 Verify Repairs" for verification of repairs.
3. No additional DDEC troubleshooting is recommended for these codes. Do all the Basic Checks and then contact Detroit Diesel Customer Service Center (313–592–5800) for instructions, providing a snapshot and code logging details.

Section 51.2.2.1
Verify Repairs

Perform these steps to verify repairs to the vehicle air system: ‪

1. Connect all connectors.
2. Start engine.
3. Perform road test.
4. Has the fault returned?
   1. If the code is logged, review this section to find the error. If the fault returns after review, try a test ECM/ECU or contact the Detroit Diesel Customer Service Center (313–592–5800).
   2. If no codes are logged, troubleshooting is complete.