PACCAR MX (2004 Emissions) Fault Code: P0501 Vehicle Speed Sensor – Data Erratic, Intermittent, or Incorrect

PACCAR MX (2004 Emissions) Fault Code: P0501 Vehicle Speed Sensor – Data Erratic, Intermittent, or Incorrect

SET CONDITIONS:
The PCI ECU (D420) detects that the measured vehicle speed is unlikely.

DIAGNOSTIC CONDITION:
This diagnostic runs:
1. When engine speed is above 900 rpm and
2. The engine speed changes more than 300 rpm in a period of more than 90 seconds and
3. Engine torque changes in a period of more than 90 seconds

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to inactive when the fault is no longer detected.

REPAIR VERIFICATION:
1. Clear all DTCs.
2. Test drive or operate the vehicle to meet the diagnostic conditions and set conditions.
3. Did the DTC come back? (Can be pending, inactive or active)
– No, repair successful
– Yes, repair unsuccessful

POSSIBLE CAUSES:
Faulty vehicle speed signal

ADDITIONAL INFORMATION:
The PCI ECU uses information from the accelerator pedal position, engine speed, and engine torque to determine if the vehicle is in motion.