Lamp:Amber

Reason:The turbocharger shaft has seized.

Effect:Possible reduced engine performance.

Circuit Description:The turbocharger speed sensor is a hall effect type sensor. The Engine Control Module (ECM) provides a 5 volt supply to the position sensor and a return circuit. As the blades of the turbocharger spin past the speed sensor, a signal is generated on the position sensor signal circuit. The ECM interprets this signal and converts it to a turbo speed.

Component Location:The turbocharger speed sensor is located on the high pressure compressor housing.

Conditions for Running the Diagnostics:This diagnostic runs continuously when the engine is running.

Conditions for Setting the Fault Code:The Engine Control Module (ECM) detected the turbocharger shaft is stuck.

Action Taken When the Fault Code is Active:1. The ECM illuminates the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.2. The ECM will estimate the turbocharger speed.

Conditions for Clearing the Fault Code:1. To validate the repair using a diagnostic road test, utilize a route that incorporates both stop and go city type driving and steady state highway type driving. It may be necessary to load the unit for certain diagnostics in the ECM to run.2. The fault code status displayed by the recommended diagnostic tool or equivalent will change to inactive immediately after the diagnostic runs and passes.3. For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.4. The “reset all faults” command in the recommended diagnostic tool or equivalent can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk:Items that can cause this fault code include:1. A malfunctioning turbo speed sensor.2. A malfunctioning turbocharger.