CM850 Electronic Control System – FAULT CODE 553

Injector Metering Rail 1 Pressure – Data Valid but Above Normal Operational Range – Moderately Severe Level


Overview

CODE REASON EFFECT
Fault Code: 553
PID: P157
SPN: 157
FMI: 0/16
LAMP: Amber
SRT: 

Injector Metering Rail 1 Pressure – Data Valid but Above Normal Operational Range – Moderately Severe Level. The ECM has detected that fuel pressure is higher than commanded pressure.

None or possible engine noise associated with higher injection pressures (especially at idle or light load). Engine power is reduced.

Fuel Rail Pressure Sensor
SMALL | MEDIUM | LARGE

Circuit Description

The electronic control module (ECM) monitors engine operating conditions, including the reading of fuel rail pressure, and changes the flow command to either increase (open the fuel pump actuator) or decrease (close the fuel pump actuator) the fuel supply to the high pressure pump.

Component Location

The fuel pump actuator is installed in the adapter on the back of the high-pressure pump.

Shop Talk

A fuel pump actuator with excessive leakage or a damaged inboard o-ring will result in high fuel rail pressures at idle or light load.

If the fuel pump actuator exhibits excessive leakage, it is possible that the fuel rail pressure will reach the opening pressure of the fuel rail pressure relief valve and Fault Code 449 may also become active.

Refer to Troubleshooting Fault Code t05-553

Last Modified:  08-Jul-2010