DD15 SPN 97/FMI 4 Troubleshooting

SPN 97/FMI 4

SPN 97/FMI 4 indicates a Water-in-Fuel circuit short to ground.‪

Check as follows:‪

1. Check for multiple codes.
   1. If any EGR faults are active at the same time, repair the open circuit between pin 67 of the MCM 120-pin connector and pin 3 of the Water-in-Fuel Sensor. Refer to “24.2.1 Verify Repairs” .
   2. If only fault 97/4 is active, go to the next step.
2. Disconnect the Water-in-Fuel Sensor.
3. Disconnect the MCM 120-pin connector.
4. Measure the resistance between pin 1 of the Water-in-Fuel Sensor connector and ground.
   1. If resistance is less than 5 Ω, repair short between pin 1 and ground. Refer to “24.2.1 Verify Repairs” .
   2. If resistance is greater than 5 Ω, go to the next step.
5. Measure the resistance between pin 2 of the Water-in-Fuel Sensor harness connector and ground.
   1. If resistance is less than 5 Ω, repair the short circuit between pin 2 of the Water-in-Fuel Sensor harness connector and ground. Refer to “24.2.1 Verify Repairs” .
   2. If resistance is greater than 5 Ω, go to the next step.
6. Measure the resistance between pin 3 of the Water-in-Fuel Sensor harness connector and ground.
   1. If resistance is less than 5 Ω, repair the short circuit between pin 2 of the Water-in-Fuel Sensor harness connector and ground. Refer to “24.2.1 Verify Repairs” .
   2. If resistance is greater than 5 Ω, review the previous steps. If the results are the same, contact Detroit Diesel Customer Support Center (313-592-5800).