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Electronic Control System Gas Plus Engines – FAULT CODE 265

Fuel Temperature Sensor Circuit – Shorted Low

Overview

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

Fuel Temperature Sensor Circuit – Shorted Low. Low voltage (short to ground) detected at the ECM.

Possible reduced performance.

Fuel Temperature Sensor Circuit
SMALL | MEDIUM | LARGE

Circuit Description

The electronic control module (ECM) uses the fuel pressure/temperature sensor (combination sensor) to measure the fuel temperature, as well as the secondary pressure.

Component Location

The fuel pressure/temperature sensor is located in the fuel housing.

Shop Talk

The fuel pressure/temperature sensor measures secondary fuel pressure and temperature at the mixer housing after the low-pressure regulator.

All temperature sensors:

  • The resistance of the sensor varies with temperature. The reading observed must compare to the following table if the sensor is functioning properly.
Temperature (°C) Temperature [°F] Resistance (ohms)
0 32 30k to 36k
25 77 9k to 11k
50 122 3k to 4k
75 167 1350 to 1500
100 212 600 to 675

Cautions and Warnings

 CAUTION 

To reduce the possibility of damaging a new ECM, all other active fault codes must be investigated prior to replacing the ECM.
 CAUTION 

To reduce the possibility of pin and harness damage, use the following test leads when taking a measurement:
Part Number 3822758 – male Deutsch/AMP/Metri-Pack test lead
Part Number 3823996 – female Weather-Pack test lead.

Troubleshooting Steps

STEPS SPECIFICATIONS
STEP 1. Check the fault codes.  
  STEP 1A. Check for multiple fault codes. Fault Code 265 inactive?
STEP 2. Check the fuel temperature sensor and circuit.  
  STEP 2A. Inspect the fuel temperature sensor and connector pins. Dirty or damaged pins?
  STEP 2B. Check the circuit response. Fault Code 263 active and Fault Code 265 inactive?
  STEP 2C. Check the fault codes and verify the sensor condition. Fault Code 265 active?
STEP 3. Check the ECM and engine harness.  
  STEP 3A. Inspect the ECM and engine harness connector pins. Dirty or damaged pins?
  STEP 3B. Check for a pin to pin short circuit in the engine harness. Greater than 100k ohms?
  STEP 3C. Check for a pin short circuit to ground. Greater than 100k ohms?
  STEP 3D. Check for an inactive fault code. Fault Code 265 inactive?
STEP 4. Clear the fault codes.  
  STEP 4A. Disable the fault code. Fault Code 265 inactive?
  STEP 4B. Clear the inactive fault codes. All fault codes cleared?

Guided Step 1 – Check the fault codes.

Guided Step 1A – Check for an inactive fault code.

Conditions

  • Turn keyswitch ON
  • Connect the INSITE™ electronic service tool.

Action

  • Use INSITE™ electronic service tool to read the fault codes.

Fault Codes 265 inactive?
YES NO
No Repair No Repair
Procedure 019-362

Guided Step 2 – Check the fuel temperature sensor and circuit.

Guided Step 2A – Inspect the fuel temperature sensor and connector pins.

Conditions

  • Turn keyswitch OFF
  • Disconnect the fuel temperature sensor from the engine harness.

Action

  • Corroded pins
  • Bent or broken pins
  • Pushed back or expanded pins
  • Wire insulation damaged
  • Moisture in or on the connector
  • Missing or damaged connector seals
  • Connector shell broken
  • Dirt or debris in or on the connector pins.

For general inspection techniques, refer to Component Connector and Pin Inspection, Procedure 019-361.

Dirty or damaged pins?
YES NO

Repair the damaged pins. Repair or replace the harness, whichever has the damaged pins.

  • Flush the dirt, debris, or moisture from the connector pins using electronic contact cleaner, Part Number 3824510.
  • Install the appropriate connector seal if it is damaged or missing.
  • Repair the harness. Refer to Procedure 019-204.
  • Replace the harness. Refer to Procedure 019-043.
No Repair

Guided Step 2B – Check the circuit response.

Conditions

  • Turn keyswitch OFF
  • Disconnect the fuel temperature sensor from the engine harness
  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool.

Action

  • Use INSITE™ electronic service tool to read the fault codes.

Fault Code 263 active and Fault Code 265 inactive?
YES NO
No Repair No Repair

Guided Step 2C – Read the fault codes and verify sensor condition.

Conditions

  • Turn keyswitch OFF
  • Connect the fuel temperature sensor to the engine harness
  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool.

Action

  • Start the engine and let it idle for one minute.
  • Use INSITE™ electronic service tool to read the fault codes.

Fault Code 265 active?
YES NO

A defective sensor has been detected.

Replace the fuel temperature sensor. Refer to Procedure 019-153.

None. The removal and installation of the connector corrected the failure.

Guided Step 3 – Check the ECM and engine harness.

Guided Step 3A – Inspect the ECM and engine harness connector pins.

Conditions

  • Turn keyswitch OFF
  • Disconnect engine harness connector 1 from the ECM.

Action

  • Corroded pins
  • Bent or broken pins
  • Pushed back or expanded pins
  • Wire insulation damaged
  • Moisture in or on the connector
  • Missing or damaged connector seals
  • Connector shell broken
  • Dirt or debris in or on the connector pins.

For general inspection techniques, refer to Component Connector and Pin Inspection, Procedure 019-361.

Dirty or damaged pins?
YES NO

A defective connection has been detected in the ECM engine connector or engine harness connectors.

Repair the damaged pins. Repair or replace the harness, whichever has the damaged pins.

  • Flush the dirt, debris, or moisture from the connector pins using electronic contact cleaner, Part Number 3824510.
  • Install the appropriate connector seal if it is damaged or missing.
  • Repair the harness. Refer to Procedure 019-204.
  • Replace the harness. Refer to Procedure 019-043.
No Repair

Guided Step 3B – Check for a pin to pin short circuit in the engine harness.

Conditions

  • Turn keyswitch OFF
  • Disconnect engine harness connector 1 and connector 2 from the ECM.
  • Disconnect the fuel temperature sensor from the engine harness.

Action

  • Measure the resistance from the fuel temperature SIGNAL pin in engine harness ECM connector 2 to all other pins in the engine connector 2.
  • Measure the resistance from the fuel temperature SIGNAL pin in engine harness ECM connector 2 to all other pins in the engine connector 1.

Refer to the circuit diagram or wiring diagram for connector pin identification.

For general resistance measurement techniques, refer to Resistance Measurements Using a Multimeter and Wiring Diagram, Procedure 019-360.

Greater than 100k ohms?
YES NO
No Repair

A pin to pin short circuit on the signal line has been detected in the engine harness.

Repair the damaged pins. Repair or replace the harness, whichever has the damaged pins.

  • Flush the dirt, debris, or moisture from the connector pins using electronic contact cleaner, Part Number 3824510.
  • Install the appropriate connector seal if it is damaged or missing.
  • Repair the harness. Refer to Procedure 019-204.
  • Replace the harness. Refer to Procedure 019-043.

Guided Step 3C – Check for a pin short circuit to ground.

Conditions

  • Turn keyswitch OFF
  • Disconnect engine harness connector 2 from the ECM.
  • Disconnect the fuel temperature sensor from the engine harness.

Action

  • Measure the resistance between the fuel temperature SIGNAL pin in engine harness ECM connector 2 and ground.

Refer to the circuit diagram or wiring diagram for connector pin identification.

For general resistance measurement techniques, refer to Resistance Measurements Using a Multimeter and Wiring Diagram, Procedure 019-360.

Greater than 100k ohms?
YES NO
No Repair

A pin to ground short circuit on the signal line has been detected in the engine harness.

Repair the damaged pins. Repair or replace the harness, whichever has the damaged pins.

  • Flush the dirt, debris, or moisture from the connector pins using electronic contact cleaner, Part Number 3824510.
  • Install the appropriate connector seal if it is damaged or missing.
  • Repair the harness. Refer to Procedure 019-204.
  • Replace the harness. Refer to Procedure 019-043.

Guided Step 3D – Check for an inactive fault code.

Conditions

  • Connect all components
  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool.

Action

  • Use INSITE™ electronic service tool to read the fault codes.

Fault Codes 265 inactive?
YES NO

None. The removal and installation of the connector corrected the failure.

Replace the ECM. Call for pre-authorization.

Refer to Procedure 019-031.

Guided Step 4 – Clear the fault codes.

Guided Step 4A – Disable the fault code.

Conditions

  • Connect all components
  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool.

Action

  • Start the engine and let it idle for one minute.
  • Use INSITE™ electronic service tool to verify that Fault Code 265 is inactive.

Fault Code 265 inactive?
YES NO
No Repair No Repair

Guided Step 4B – Clear the inactive fault codes.

Conditions

  • Connect all components
  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool.

Action

  • Use INSITE™ electronic service tool to erase the inactive fault codes.

All fault codes cleared?
YES NO
No Repair No Repair
Repair complete
Appropriate troubleshooting charts
Last Modified:  22-Sep-2004
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