MBE 900 DDEC VI Troubleshooting – Section 131.2 SPN 4226/FMI 1

Section 131.2
SPN 4226/FMI 1

This diagnosis is typically the turbocharger compressor inlet differential pressure is too low (High Box).‪

Section 131.2.1
Low Differential Pressure Check

Check as follows:‪

1. Check entire air intake system for leaks, restrictions or damage.
   1. If leaks or damage are found, repair as necessary. Refer to "131.2.1.1 Verify Repairs" .
   2. If no leaks or damage is found, go to the next step.
2. Disconnect the Inlet Air Delta P Sensor.
3. Inspect the Inlet Air Delta P Sensor harness connector for bent, corroded or spread pins.
   1. If connector pin damage is found, repair as necessary. Refer to "131.2.1.1 Verify Repairs" .
   2. If no pin damage is found, go to the next step.
4. Inspect the Inlet Air Delta P Sensor pressure tubes for leaks, kinks or restrictions.
   1. If damaged tubes are found, repair as necessary. Refer to "131.2.1.1 Verify Repairs" .
   2. If no tube damage is found, replace the Inlet Air Delta P Sensor. Refer to "131.2.1.1 Verify Repairs" .

Section 131.2.1.1
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.
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.