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Electronic Control System Gas Plus Engines – FAULT CODE 511

Fuel Control Valve Circuit – Shorted Low

Overview

CODE REASON EFFECT
Fault Code: 511
PID: S18
SPN: 633
FMI: 4
LAMP: Red
SRT: 

Fuel Control Valve Circuit – Shorted Low. Low voltage detected at the ECM.

Engine will die or not start.

Fuel Control Valve Circuit
SMALL | MEDIUM | LARGE

Circuit Description

The electronic control module (ECM) uses this valve to meter the fuel into the fuel housing.

Component Location

The fuel control valve is located in the fuel housing next to the gas mass flow sensor.

Shop Talk

This valve is normally closed when no power is applied. The valve is pulse-width modulated.

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 3822917 – female Deutsch/AMP/Metri-Pack test lead
Part Number 3823994 – female Deutsch test lead.

Troubleshooting Steps

STEPS SPECIFICATIONS
STEP 1. Check the fault codes.  
  STEP 1A. Check for an inactive fault code. Fault Code 511 inactive?
STEP 2. Check the fuel control valve and circuit.  
  STEP 2A. Inspect the fuel control valve and connector pins. Dirty or damaged pins?
  STEP 2B. Check for an open circuit in the fuel control valve. 2 ohms to 5 ohms?
  STEP 2B-1. Check for a short to ground in the fuel control valve.
  STEP 2C. Check the fuel control valve supply voltage, supply line and return circuit. Greater than 5 VDC?
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 short circuit to ground. Greater than 100k ohms?
  STEP 3C. Check for a pin to pin short circuit in the engine harness. Greater than 100k ohms?
  STEP 3D. Check for an inactive fault code. Fault Code 511 inactive?
STEP 4. Clear the fault codes.  
  STEP 4A. Disable the fault code. Fault Code 511 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 Code 511 inactive?
YES NO
No Repair No Repair

Guided Step 2 – Check the fuel control valve and circuit.

Guided Step 2A – Inspect the fuel control valve and connector pins.

Conditions

  • Turn keyswitch OFF
  • Disconnect the fuel control from the valve engine harness.

Action

  • Corroded pins
  • Bent or broken pins
  • Pushed back or expanded pins
  • Wire insulation damage
  • 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, or replace the valve, 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.
  • Replace the valve. Refer to Procedure 019-102.
 No Repair

Guided Step 2B – Check for an open circuit in the fuel control valve.

Conditions

  • Turn keyswitch OFF
  • Disconnect the fuel control valve from the engine harness.

Action

  • Measure the resistance between the fuel control valve output pin and the fuel control valve RETURN pin at the fuel control valve connector.

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

2 ohms to 5 ohms?
YES NO
No Repair

Replace the fuel control valve. Refer to Procedure 019-102.

Guided Step 2B-1 – Check for a short to ground in the fuel control valve.

Conditions

  • Turn keyswitch OFF
  • Disconnect the fuel control valve from the engine harness.

Action

  • Measure the resistance between the fuel control valve SUPPLY pin and ground at the fuel control valve connector.

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

Replace the fuel control valve. Refer to Procedure 019-102.

Guided Step 2C – Check the fuel control valve supply voltage, supply line and return circuit.

Conditions

  • Turn keyswitch OFF
  • Disconnect the fuel control valve from the engine harness
  • Turn keyswitch ON.

Action

  • Measure the voltage between the fuel control valve output pin to the fuel control valve RETURN pin at the fuel control valve connector of the engine harness.

Greater than 5 VDC?
YES NO
No Repair No Repair

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 damage
  • 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 1 or the engine harness connector.

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 short to ground.

Conditions

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

Action

  • Measure the resistance between the fuel control valve output pin in the engine harness ECM engine connector 1 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 fuel control valve output 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 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 control valve from the engine harness.

Action

  • Measure the resistance between the fuel control valve SUPPLY pin in the engine harness ECM connector 1 to all other pins in the engine connector 1.
  • Measure the resistance between the fuel control valve SUPPLY pin in the engine harness ECM connector 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 fuel control valve supply 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 the INSITE™ electronic service tool.

Action

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

Fault Code 511 inactive?
YES NO
No Repair

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 the INSITE™ electronic service tool.

Action

  • Use INSITE™ electronic service tool to verify that Fault Code 511 is inactive.

Fault Code 511 inactive?
YES NO
No Repair No Repair

Guided Step 4B – Clear the inactive fault codes.

Conditions

  • Connect all components
  • Turn keyswitch ON
  • Connect the 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:  09-Sep-2004
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