AXLE GP-REAR 1185836 - Caterpillar

Which Generate This Code:The Electronic Control Module (ECM) detects an excessive pressure drop across the fuel filter element. Information on default settings and ranges for this event code can be found in Troubleshooting, "Event Codes".System Response:The event code is logged.E390(1)
There are no performance effects.E390(2)
The engine power will be derated.The fuel filter element may need to be replaced.Test Step 1. Replace the Fuel Filter Element
Replace the fuel filter element.
Restart the engine and check for an active event code.Expected Result:The event code is no longer active.Results:
OK - The event code is no longer active.STOP
Not OK - The event code is active.Repair: Perform the diagnostic functional test Troubleshooting, "Fuel Filter Differential Pressure Switch Circuit - Test".STOP