Cummins ISB CM850 (2003-06) Fault Code: 553 PID: 157 SPN: 157 FMI: 0 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.
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.
1)Replace the rail fuel pressure sensor.
2)Replace the fuel gear pump assembly.
3)Replace the damaged o-ring.
4)Replace the fuel pump actuator.
Cummins ISB CM850 (2003-06) Fault Code: 551 (SSS) PID: SID 230 SPN: 558 FMI: 4 Accelerator Pedal or Lever Idle Validation Circuit – Voltage Below Normal or Shorted to Low Source. No voltage detected simultaneously on both the idle validation off-idle and on-idle circuits.
Cummins ISB CM850 (2003-06) Fault Code: 551 (NISS) PID: SID 230 SPN: 556 FMI: 4 Accelerator Pedal or Lever Idle Validation Circuit – Voltage Below Normal or Shorted to Low Source. No voltage detected simultaneously on both the idle validation off-idle and on-idle circuits.
Cummins ISB CM850 (2003-06) Fault Code: 551 (ISS) PID: SID 230 SPN: 558 FMI: 4 Accelerator Pedal or Lever Idle Validation Circuit – Voltage Below Normal or Shorted to Low Source. No voltage detected simultaneously on both the idle validation and off-idle and on-idle switches.
Cummins ISB CM850 (2003-06) Fault Code: 545 PID: SID 32 SPN: 1188 FMI: 7 Turbocharger 1 Wastegate Control ? Mechanical System Not Responding Properly or Out of Adjustment. Intake manifold pressure has exceeded the maximum limit for the given engine rating.
Cummins ISB CM850 (2003-06) Fault Code: 529 PID: SID 51 SPN: 703 FMI: 3 Auxiliary Input/Output 3 Circuit – Voltage Above Normal, or Shorted to High Source. High signal voltage has been detected at the auxiliary input/output 3 circuit.
Cummins ISB CM850 (2003-06) Fault Code: 528 PID: 93 SPN: 93 FMI: 2 Auxiliary Alternate Torque Validation Switch – Data Erratic, Intermittent, or Incorrect. An error has been detected in the alternate torque switch circuit.
