CM870 and ISX Engines – FAULT CODE 265

Engine Fuel Temperature Sensor Circuit – Voltage Below Normal or Shorted to Low Source


Overview

CODE REASON EFFECT
Fault Code: 265
PID: P174
SPN: 174
FMI: 4/4
LAMP: Amber
SRT: 

Engine Fuel Temperature Sensor Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at engine fuel temperature circuit.

May have white smoke and low power when engine is cold.

Engine Fuel Temperature Sensor Circuit
SMALL | MEDIUM | LARGE

Circuit Description

The engine fuel temperature sensor is used by the electronic control module (ECM) to monitor the engine fuel temperature. The ECM monitors the voltage on the signal pin and converts this to a temperature value. The engine fuel temperature value is used by the ECM to adjust fuel delivery to the injectors.

Component Location

The engine fuel temperature sensor is located on the lower rear of the integrated fuel system module (IFSM). Refer to Section E for a detailed component location view.

Shop Talk

Beginning with ESN 14039654, the temperature sensor return circuit was separated from the pressure sensor return circuit. For ESNs prior to this and with engine wiring harness Part Number 3682854, refer to the Common Pressure/Temperature Sensor Return Circuit above. For this ESN and greater or for any other engine wiring harness part number, refer to the Separate Pressure/Temperature Sensor Return Circuit above.

The engine fuel temperature sensor shares return wires in the engine harness with other sensors. A shorted return can cause multiple fault codes to be active. Before troubleshooting Fault Code 265, check for multiple fault codes.

Possible causes of this fault code include:

  • Signal shorted to ground in the harness or ECM
  • Signal shorted to return or ground in the sensor.
Temperature (°C) Temperature (°F) Resistance (ohms)
0 32 30k to 37k
25 77 9.3k to 10.7k
50 122 3.2k to 3.8k
80 176 1.0k to 1.3k
95 203 700 to 800

Refer to Troubleshooting Fault Code t05-265

Last Modified:  01-Sep-2010