Engine-Codes - Generic - P1185

P1185 - Fuel Pressure Monitoring-Maximum Pressure Exceeded

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3  What is this?

P1185 Possible Causes

  • Faulty Fuel pressure regulator valve (Stuck Open)
  • Faulty Rail pressure sensor
  • Rail pressure sensor harness is open or shorted
  • Rail pressure sensor circuit poor electrical connection

How do I fix code P1185

Check the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

Cost of diagnosing the P1185 code

Labor: 1.0

The cost of diagnosing the P1185 code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.

Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)

P1185 Meaning

As inputted rail pressure sensor signal, Engine Control Module (ECM) of Common rail diesel engine controls Fuel pressure regulator valve(integrated with high press. pump) in order to maintain optimum rail pressure according to current engine rpm and load.
However when the problem that leads rail pressure to out of target value intended by ECM occurs due to mechanical or electronical reason, ECM shuts engine down and sets Diagnostic Trouble Code (DTC) by limiting fuel (stops injector operation) in order to prevent engine from being controlled abnormally. "rail pressure monitoring error" is the DTC which diagnose 1).supplying state of low pressure fuel and 2).mechanical operating conditions of high pressure pump and 3) indirectly based on RPS output voltage and RPS duty. thus, repair relevant to this DTC requires mechanics the total understand of fuel system.

P1185 More Information

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