DD15 Troubleshooting – Section 81.4 SPN 1077/FMI 15

Section 81.4
SPN 1077/FMI 15

The fault condition is typically related to an internal or external leakage of the high pressure fuel system. The MCM monitors the rail pressure and when a leakage rate is greater than 100 l/h, the MCM sets the code. There is no fault reaction (limp home mode) associated to this code. This fault can occur due to the conditions listed below:‪

• External fuel leakage between the high pressure pump and injectors
• High pressure pump (pumping elements)
• Injector (amplifier or needle) leakage
• Pressure limiting valve leakage (internal)

Check as follows:‪

1. Check for multiple codes
   1. If additional fault codes are present along with 1077/15, service the additional fault codes first
   2. If only 1077/15 is present go to the next step.
2. Turn the ignition OFF.
3. Inspect the following fuel system components for external leakage: high pressure pump, lines to fuel rail, fuel rail, pressure limiting valve (PLV), and fuel lines from rail to injector.
   1. If leakage was found, repair and refer to "81.4.1 Verify Repairs" .
   2. If no leakage was found, go to next step.
4. Perform rail pressure bleed off test. Refer to "16.9.1 RPBO Test Using DDDL" , “RPBO Test using DDDL.”
   1. If the RPBO test failed; go to next step.
   2. If the RPBO test passed, no problem found.
5. Perform pressure limiting valve (PLV) leakage test. Refer to "16.10 Pressure Limiting Valve Leakage" , “Pressure Limiting Valve Leakage.”
   1. If the pressure limiting valve (PLV) test passed; go to next step.
   2. If the pressure limiting valve (PLV) test failed; replace pressure limiting valve and refer to "81.4.1 Verify Repairs" .
6. Perform amplifier/needle return measurements. Refer to "16.6 High Amplifier/Needle Return Flow (Version 4 Fuel System)" , “High Amplifier/Needle Return Flow”.
   1. If the amplifier/needle return flow test passed; no problem found.
   2. If the amplifier/needle return flow test failed; fix as necessary and refer to "81.4.1 Verify Repairs" .

Section 81.4.1
Verify Repairs

Verify repairs as follows:‪

1. Turn ignition OFF.
2. Reconnect any electrical connections that were disconnected to perform the diagnosis.
3. Clear codes with DDDL 7.0 or latest version.

   ENGINE EXHAUST ‪
   To avoid injury from inhaling engine exhaust, always operate the engine in a well-ventilated area. Engine exhaust is toxic.‪

4. Start and bring engine up to operating temperature (over 140°F/60°C).
5. Verify operation is satisfactory and no warning lamps illuminate. If warning lamps illuminate, troubleshoot the codes. If assistance is required, call the Detroit Diesel Customer Support Center at 313–592–5800.