Circuit DescriptionThe sensor supply 5 of the electronic control module (ECM) provides a (+) 5-VDC supply for the aftertreatment diesel particulate filter differential pressure sensor, remote accelerator, engine coolant level sensor, fan speed sensor, and the accelerator position sensor 2.

Component LocationSensor supply number 5 is located in the ECM OEM harness connector and provides a 5-VDC supply to various components in the OEM harness.

Conditions for Running the DiagnosticsThis diagnostic runs continuously when the keyswitch is in the ON position or when the engine is operating.

Conditions for Setting the Fault CodesThe ECM detects that the sensor supply 5 signal voltage is greater than 5.25-VDC for more than 1 second.

Action Taken When the Fault Code is ActiveThe ECM illuminates the amber CHECK ENGINE light and/or Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.The engine will have limp-home throttle control only.Conditions for Clearing the Fault CodeTo validate the repair, start the engine and let it idle for 1 minute.The fault code status displayed by INSITE? electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.The ECM will turn off the amber CHECK ENGINE lamp after the diagnostic runs and passes.For On-Board Diagnostic (OBD) engines, the ECM will turn off the MIL after three consecutive trips where the diagnostic runs and passes.The ?Reset All Faults? command in INSITE? electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications

Shop TalkHigh voltage on the 5-VDC supply wire can be caused by a short circuit to a power supply, a damaged sensor, or a damaged ECM power supply.

Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.

For intermittent power supply and datalink communication issues with Aftertreatment Components, it is highly recommended that the OEM Power Distribution Center fuses and relays be thoroughly checked for loose, missing or intermittent connections.

Possible Cause:1) OEM harness2) ECM calibration