DD15 SPN 3597/FMI 4 Troubleshooting

SPN 3597/FMI 4

This diagnosis is typically Proportional Valve Bank 1 circuit failed low.‪

Check as follows:‪

1. Turn the ignition OFF.
2. Disconnect the front valve cover injector harness connector.
3. Measure the resistance between pin 14 on the valve cover side of the injector harness connector and ground.
   
   1. If the resistance is less than 5 Ω, go to step 4 .
   2. If resistance is greater than 5 Ω, go to step 6 .
4. Remove the valve cover and disconnect the wires from the low engine brake solenoid.
5. Measure the resistance between pin 14 on the valve cover side of the injector harness connector and ground.
   1. If the resistance is greater than 5 Ω, replace the solenoid.
   2. If the resistance is less than 5 Ω, replace the front under valve cover injector harness.
6. Disconnect the MCM 120–pin connector.
7. Measure the resistance between pin 14 on the engine harness side of the injector harness connector and ground.
   1. If the resistance is less than 5 Ω, go to the next step.
   2. If the resistance is greater than 5 Ω, go to step 10 .
8. Disconnect the engine 31–pin connector.
9. Again measure the resistance between pin 14 on the engine harness side of the injector harness connector and ground.
   1. If the resistance is less than 5 Ω, repair short to ground between pin 91 of the MCM 120–pin connector and the valve cover injector harness connector or the 31 pin connector. Refer to “116.1.1 Verify Repairs” .
   2. If the resistance is greater than 5 Ω, repair short to ground between pin 22 of the 31–pin connector on the vehicle side of the harness and the fan control solenoid. Refer to “116.1.1 Verify Repairs” .
10. Disconnect the Air Seal Pressure Regulator Valve connector.
11. Measure the resistance between pin 2 of the Air Seal Pressure Regulator Valve connector and ground.
    1. If the resistance is less than 5 Ω, repair short to ground between pin 93 of the MCM 120–pin connector and the Air Seal Pressure Regulator Valve connector. Refer to “116.1.1 Verify Repairs” .
    2. If resistance is greater than 5 Ω, replace the Air Seal Pressure Regulator Valve.

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.