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: 241 PID: 84 SPN: 84 FMI: 2 Vehicle Speed Sensor Circuit – Data Erratic, Intermittent or Incorrect. The ECM lost the vehicle speed signal.

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.

Possible repairs:

1)Repair or replace the OEM harness.
2)Remove the device or contact an OEM representative.
3)Replace the gear or tone wheel.
4)Repair Location or OEM dealer if all the steps have been completed and checked again.