PACCAR PX-8 CM2150 (2007-09) Fault Code: 686 PID: 103 SPN: 103 FMI: 2 Turbocharger 1 Speed – Data Erratic, Intermittent, or Incorrect. An invalid turbocharger speed signal has been detected by the ECM.

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.

This fault code is logged when the ECM detects a turbocharger speed that is greater than the speed that is physically achievable by the turbocharger. Usually this indicates a faulty sensor or incorrect speed signals from the turbocharger speed sensor. This fault can be caused by failures in the following components:

1)Turbocharger speed sensor
2)Engine harness
3)ECM power supply or grounds
4)Electronic vehicle accessories which emit excessive electromagnetic interference.

This fault becomes inactive any time the ECM detects a valid turbocharger speed. If the fault occurs intermittently:

1)Look for causes of intermittent open circuit or short circuits in the turbocharger speed sensor circuit (including the speed sensor pigtail connector)
2)Look for sources of electronic noise such as poorly installed vehicle electronic components
3)Be sure that the vehicle chassis grounds are in good condition
4)Be sure that the ECM power supply and ground circuits are in good condition and that this power supply is not shared with other vehicle electronics.

Possible repairs:

1)Repair or replace the damaged connector or turbocharger speed sensor.
2)Replace the turbocharger speed sensor.
3)Repair or replace the engine harness or connector(s).
4)Replace the ECM.