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.

Posted by PerDiezel Solutions on January 18, 2026

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.

This fault code become active when the intake manifold pressure exceeds the maximum pressure limit for a given engine rating.

Possible causes:

1)Malfunctioning turbocharger wastegate
2)Wastegate tampering
3)Wrong turbocharger part
4)Possible tampering of the fuel system or turbocharger system.

On-Board Diagnostics (OBD) Information:

1)The ECM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2)The ECM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. The MIL lamp and fault code can also be cleared using the INSITE? service tool.
3)The fault code will be cleared from memory after 40 consecutive drive cycles where the diagnostic runs and passes.

Possible repairs:

1)Replace the intake manifold pressure sensor.
2)Replace the turbocharger wastegate actuator.

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.

Cummins ISB CM850 (2003-06) Fault Code: 527 PID: SID 154 SPN: 702 FMI: 3 Auxiliary Input/Output 2 Circuit Voltage Above Normal or Shorted to High Source. High signal voltage or open circuit has been detected at the auxiliary input and output 2 circuit.

Cummins ISB CM850 (2003-06) Fault Code: 523 PID: 89 SPN: 611 FMI: 2 Auxiliary Intermediate (PTO) Speed Switch Validation – Data Erratic, Intermittent, or Incorrect. The position of the intermediate speed control switch 1 does not match the position of the intermediate speed control validation switch.

Cummins ISB CM850 (2003-06) Fault Code: 499 PID: 98 SPN: 98 FMI: 4 Engine Oil Level Sensor Circuit – Voltage Below Normal or Shorted to Low Source. The engine oil level sensor has detected an internal failure.

Cummins ISB CM850 (2003-06) Fault Code: 498 PID: 98 SPN: 98 FMI: 3 Engine Oil Level Sensor Circuit – Voltage Above Normal or Shorted to High Source. The engine oil level sensor has detected an internal failure

WARNING!