Cummins ISB CM850 (2003-06) Fault Code: 1892 PID: 84 SPN: 84 FMI: 1 Wheel-Based Vehicle Speed ? Data Valid but Below Normal Operational Range ? Moderately Severe Level. The ECM lost the vehicle speed signal.

Posted by PerDiezel Solutions on January 18, 2026

There are multiple types of vehicle speed sensors. Various types include magnetic pickup, data link, digital, and tachograph. Refer to your OEM for the specific type installed on the vehicle.

This fault is set active when the ECM loses a vehicle speed signal when other engine conditions indicate the vehicle is moving. The fault can also become active if there is a series of clutch, service brake or throttle movements with no vehicle movement. The fault is set inactive when the ECM receives a vehicle speed signal greater than zero.

Since the vehicle speed sensor is an OEM installed component, this troubleshooting procedure will not catch all failures of the circuit due to components not under Cummins Inc. control. Sensor resistance values, data link speed sensors and tachographs are not fully covered under this procedure. For more information on those components, please refer to the OEM troubleshooting and repair manual.

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)Repair or replace the OEM harness.
2)Repair or replace the gear or tone wheel.

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Cummins ISB CM850 (2003-06) Fault Code: 1849 PID: SPN: 3241 FMI: 10 Exhaust Gas Temperature 1 ? Abnormal Rate of Change. The catalyst inlet temperature sensor is not responding to a change in engine operating conditions.

Cummins ISB CM850 (2003-06) Fault Code: 1848 PID: 105 SPN: 105 FMI: 10 Intake Manifold 1 Temperature ? Abnormal Rate of Change. The intake manifold temperature sensor is not responding to a change in engine operating conditions.

Cummins ISB CM850 (2003-06) Fault Code: 1846 PID: SPN: 97 FMI: 4 Water-in-Fuel Indicator Sensor Circuit – Voltage Below Normal or Shorted to Low Source (For Generator Engines Only). Low voltage detected at the water-in-fuel indicator circuit.

Cummins ISB CM850 (2003-06) Fault Code: 1845 PID: SPN: 97 FMI: 3 Water-in-Fuel Indicator Sensor Circuit – Voltage Above Normal or Shorted to High Source (For Generator Engines Only). High voltage detected at the water-in-fuel indicator circuit.

Cummins ISB CM850 (2003-06) Fault Code: 1718 PID: SPN: 1322 FMI: 11 Engine Misfire for Multiple Cylinders ? Condition Exists. Engine misfire has been detected in multiple cylinder numbers.

WARNING!