PACCAR PX-8 CM2150 (2007-09) Fault Code: 241 PID: 84 SPN: 84 FMI: 2 Wheel-Based Vehicle Speed – Data Erratic, Intermittent, or Incorrect. The ECM lost the vehicle speed signal.

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe® Online for applicable fixes to the calibration stored in the ECM. If necessary, recalibrate the ECM.

There are multiple types of vehicle speed sensors. Various types include magnetic pickup, data link, digital, and tachograph. Refer to the 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 malfunctions 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)Repair or replace the gear or tone wheel.