Cummins ISB CM850 (2003-06) Fault Code: 268 PID: 94 SPN: 94 FMI: 2 Injector Metering Rail 1 Pressure – Data Erratic, Intermittent, or Incorrect. The ECM has detected that the fuel pressure signal is not changing.
This fault code can become active any time the engine is loaded and the ECM detects that fuel pressure in the rail fuel is not changing. This fault code will become inactive whenever the ECM is powered down or if the ECM detects that the engine is loaded and the fuel pressure is changing normally. If there are many inactive counts of this fault code or if the fault is not repeatable, look for signs of tampering to the fuel pressure sensor circuit. If the fault code occurs intermittently (can not be reproduced during a road test), then inspect each of the following for poor connections or damage:
1)Replace the rail fuel pressure sensor.
2)Repair or replace the engine harness.
3)Replace the ECM.
Cummins ISB CM850 (2003-06) Fault Code: 253 PID: 98 SPN: 98 FMI: 1 Engine Oil Level ? Data Valid But Below Normal Operational Range ? Most Severe Level. Very low oil level has been detected by the oil level sensor.
Cummins ISB CM850 (2003-06) Fault Code: 245 PID: SID 33 SPN: 647 FMI: 4 Fan Control Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at the fan control circuit when commanded on.
Cummins ISB CM850 (2003-06) Fault Code: 242 PID: 84 SPN: 84 FMI: 10 Vehicle Speed Sensor Circuit Tampering Has Been Detected – Abnormal Rate of Change. Invalid or inappropriate vehicle speed signal. Signal indicates an intermittent connection or VSS tampering.
Cummins ISB CM850 (2003-06) Fault Code: 241 PID: 84 SPN: 84 FMI: 2 Vehicle Speed Sensor Circuit – Data Erratic, Intermittent or Incorrect. The ECM lost the vehicle speed signal.
Cummins ISB CM850 (2003-06) Fault Code: 238 PID: SID 232 SPN: 611 FMI: 4 Sensor Supply 3 Circuit – Voltage Below Normal, or Shorted to Low Source. Low voltage detected on the +5 volt sensor supply circuit to the engine speed sensor.
Cummins ISB CM850 (2003-06) Fault Code: 237 PID: SID 30 SPN: 644 FMI: 2 External Speed Command Input (Multiple Unit Synchronization) – Data Erratic, Intermittent, or Incorrect. The throttle input signal to the primary or secondary engine for multiple unit synchronization is less than 3 percent or more than 97 percent.