Volvo All Engines (2017 Emissions) Fault Code: U30004B PID: EMS Electronic Control Unit

Volvo All Engines (2017 Emissions) Fault Code: U30004B PID: EMS Electronic Control Unit

Circuit description
This diagnostic trouble code (DTC) is used to indicate temperatures at the engine control module (ECM). The DTC will be set if the ECM temperature is too high. A faulty ECM temperature can lead to power loss.

Conditions for diagnostic trouble code (DTC)
The engine control module (ECM) is overheated

Observable symptoms
Temperature above normal: Yellow lamp lights up
Temperature critically above range: Red lamp lights up

Probable cause
1) Common rail safety valve: The safety valve is open
2) Thermostatic valve: Stuck in one position
3) Driving in Limp-home mode for too long
4) Poor cooling
5) Extreme driving conditions