DD15 Troubleshooting – Section 24.1 SPN 97/FMI 3

Section 24.1
SPN 97/FMI 3

SPN 97/FMI 3 indicates a Water-in-Fuel Sensor open circuit.‪

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 "24.1.1 Verify Repairs" .
   2. If only fault 97/3 is active, go to the next step.
2. Disconnect the Water-in-Fuel Sensor.
3. Turn the ignition ON (key ON, engine OFF).
4. Measure the voltage between pins 1 and 3 of the Water-in-Fuel Sensor harness connector.
   1. If the voltage is between 2.75 and 3.25 volts, go to step 6 .
   2. If the voltage is less than 2.75 volts, go to the next step.
5. Measure the voltage between pin 1 of the Water-in-Fuel Sensor harness connector and ground.
   1. If the voltage is between 2.75 and 3.25 volts, repair the open circuit between pin 3 of the Water-in-Fuel Sensor harness connector and pin 55 of the MCM 120-pin connector. Refer to "24.1.1 Verify Repairs" .
   2. If the voltage is less than 2.75 volts, repair the open circuit between pin 1 of the Water-in-Fuel Sensor harness connector and pin 71 of the MCM 120-pin connector. Refer to "24.1.1 Verify Repairs" .
6. Disconnect the MCM 120-pin connector and measure the resistance between pin 57 and pin 2 of the Water-in-Fuel Sensor harness connector.
   1. If the resistance is less than 5 Ω, repair the short between pin 2 and 57 of the MCM 120-pin connector. Refer to "24.1.1 Verify Repairs" .
   2. If the resistance is greater than 5 Ω, replace the sensor. Refer to "24.1.1 Verify Repairs" .

Section 24.1.1
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.

   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.