DD15 SPN 111/FMI 1 Troubleshooting

SPN 111/FMI 1

This diagnosis typically coolant level low.‪

Check as follows:‪

1. Turn the vehicle ignition switch ON (key On, engine OFF).
2. Check for multiple codes.
   1. If other faults are active in addition to fault 111/1, troubleshoot the other faults first.
   2. If only fault 111/1 is active, go to the next step.
3. Check the coolant level in the reservoir.
   1. 1. If the coolant level in the reservoir is not within limit, go to the next step.
      2. If the coolant level in the reservoir is within limit, replace the sensor. refer to “28.1.1 Verify Repairs” .
   
4. Check for coolant leak at cylinder head gasket.
5. Check for coolant leak at air compressor head gasket.
6. Check for external coolant leak at hose connections.
7. Check for coolant in oil.
8. Check for loose or faulty radiator cap.
9. When these checks and subsequent repairs are finished, refer to “28.1.1 Verify Repairs” .