CM2150 Electronic Control System – FAULT CODE 386

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Overview

ISB, ISC, and ISL with CM2150 – Sensor Supply 1 Circuit SMALL | MEDIUM | LARGE

Circuit Description

The sensor supply 1 of the electronic control module (ECM) provides a 5 VDC supply for the engine camshaft position sensor, fuel rail pressure sensor, exhaust gas pressure sensor, intake manifold pressure sensor, crankcase pressure sensor, exhaust gas recirculation (EGR) differential pressure sensor, barometric pressure sensor, engine oil pressure sensor and EGR position sensor.

Component Location

Sensor supply number 1 is located in the ECM engine harness connector and provides a 5 VDC supply to various pressure sensors.

Conditions for Running the Diagnostics

This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes

The ECM detects that the sensor supply 1 signal voltage is greater than 5.25-VDC for more than 1 second.

Action Taken When the Fault Code is Active

• The ECM illuminates the amber CHECK ENGINE light immediately when the diagnostic runs and fails.
• A default value is used for all the sensors tied to the 5 VDC supply.

Conditions for Clearing the Fault Code

The ECM will turn off the amber CHECK ENGINE light immediately after the diagnostic runs and passes.

Shop Talk

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. Refer to Procedure 019-032 (ECM Calibration Code) in Section 19 in the corresponding Troubleshooting and Repair Manual for the engine being serviced.

Low voltage on the +5 volt supply wire can be caused by a short circuit to ground in a supply wire, a short circuit between a supply wire and a return wire, a failed sensor, or a failed ECM power supply.

Refer to Troubleshooting Fault Code t05-386