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Electronic Control System Gas Plus Engines – FAULT CODE 239

Sensor Supply Voltage Number 3 Circuit – Shorted High

Overview

CODE REASON EFFECT
Fault Code: 239
PID: S239
SPN: 620
FMI: 3
LAMP: Amber
SRT: 

Sensor Supply Voltage Number 3 Circuit – Shorted High. High voltage detected at sensor supply number 3 circuit.

Possible reduced performance.

Sensor Supply Voltage Number 3 Circuit
SMALL | MEDIUM | LARGE

Circuit Description

This is the voltage supply for the gas mass flow sensor.

Component Location

The sensor supply circuit number 3 circuit is contained in the engine wiring harness.

Shop Talk

When testing the resistance of the wires, make sure that the ECM and OEM connectors are disconnected.

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 lead when taking a measurement:
Part Number 3822758 – male Deutsch/AMP/Metri-Pack test lead.

Troubleshooting Steps

STEPS SPECIFICATIONS
STEP 1. Check the fault codes.  
  STEP 1A. Check for an inactive fault code. Fault Code 239 inactive?
STEP 2. Check the ECM and engine harness.  
  STEP 2A. Inspect the ECM and engine harness connector pins. Dirty or damaged pins?
  STEP 2B. Check for a pin to pin short circuit in the engine harness. Greater than 100k ohms?
  STEP 2C. Check for an inactive fault code. Fault Code 239 inactive?
STEP 3. Clear the fault codes.  
  STEP 3A. Disable the fault code. Fault Code 239 inactive?
  STEP 3B. 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 INSITE™ electronic service tool.

Action

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

Fault Code 239 inactive?
YES NO
No Repair No Repair

Guided Step 2 – Check the ECM and engine harness.

Guided Step 2A – Inspect the ECM and engine harness connector pins.

Conditions

  • Turn keyswitch OFF
  • Disconnect engine harness connector 1 and connector 2 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 connector or engine harness connector.

Repair the damaged pins. Repair or replace the engine 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 engine harness. Refer to Procedure 019-204.
  • Replace the engine harness. Refer to Procedure 019-043.
 No Repair

Guided Step 2B – Check for a pin to pin short circuit in the engine harness.

Conditions

  • Turn keyswitch OFF
  • Disconnect the engine harness connector 1 and connector 2 from the ECM
  • Disconnect the gas mass flow sensor from the engine harness
  • Make sure all components connected to sensor supply number 3 circuit are disconnected.

Action

  • Measure the resistance between the sensor SUPPLY number 3 pin in engine harness ECM connector 1 to all other pins in the engine connector 1.
  • Measure the resistance between the sensor SUPPLY number 3 pin in engine harness ECM connector 1 to all other pins in the engine connector 2.

Greater than 100k ohms?
YES NO
No Repair

A pin to pin short circuit on the sensor supply number 3 circuit line has been detected in the engine harness.

Repair the damaged pins. Repair or replace the engine 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 engine harness. Refer to Procedure 019-204.
  • Replace the engine harness. Refer to Procedure 019-043.

Guided Step 2C – 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 Code 239 inactive?
YES NO
No Repair

Replace the ECM. Call for pre-authorization.

Refer to Procedure 019-031.

Guided Step 3 – Clear the fault codes.

Guided Step 3A – 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 the fault code is inactive.

Fault Code 239 inactive?
YES NO
No Repair No Repair

Guided Step 3B – 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:  03-Sep-2004
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Published by Jack

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