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Electronic Control System Gas Plus Engines – FAULT CODE 118

Fuel Pressure Sensor Circuit, Primary – Shorted High

Overview

CODE REASON EFFECT
Fault Code: 118
PID: P135
SPN: 135
FMI: 3
LAMP: Yellow
SRT: 

Fuel pressure sensor, primary, shorted high.

None.

Fuel Pressure Sensor Circuit
SMALL | MEDIUM | LARGE

Circuit Description

The ECM uses this sensor to monitor the primary fuel pressure into the engine.

Component Location

The fuel pressure sensor is located in the low-pressure regulator housing.

Shop Talk

The fuel pressure sensor is used to detect the high-pressure fuel supplied to the engine from the OEM pressure regulator. The sensor is diagnostic only and does not affect fueling calculations to the engine. Disconnect the sensor before carrying out any wiring checks.

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.

Troubleshooting Steps

STEPS SPECIFICATIONS
STEP 1. Check the fault codes.  
  STEP 1A. Check for Fault Code 386. Fault Code 386 active?
  STEP 1B. Check for inactive fault codes. Fault Code 118 inactive?
STEP 2. Check the fuel pressure sensor and circuit.  
  STEP 2A. Inspect the fuel pressure sensor and connector pins. Dirty or damaged pins?
  STEP 2B. Check the circuit response. Fault Code 119 active and Fault Code 118 inactive?
  STEP 2C. Check the sensor supply voltage and return circuit. 4.5 to 5.25 VDC?
  STEP 2D. Check the fault codes and verify sensor conditions. Fault Code 118 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 an open circuit in the engine harness. Less than 10 ohms?
  STEP 3C. Check for a pin to pin short circuit in the engine harness. Greater than 100k ohms?
  STEP 3D. Check for a pin to pin short circuit in the engine harness. Greater than 1000 ohms?
  STEP 3E. Check for an inactive fault code. Fault Code 118 inactive?
STEP 4. Clear the fault codes.  
  STEP 4A. Disable the fault code. Fault Code 118 inactive?
  STEP 4B. Clear the inactive fault codes. All fault codes cleared?

Guided Step 1 – Check the fault codes.

Guided Step 1A – Check for Fault Code 386.

Conditions

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

Action

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

Fault Code 386 active?
YES NO
No Repair No Repair
Fault Code 386

Guided Step 1B – 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 118 inactive?
YES NO
No Repair No Repair
Procedure 019–362, Inactive or Intermittent Fault Code

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

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

Conditions

  • Turn keyswitch OFF.
  • Disconnect the fuel pressure sensor from the 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 damage
  • Dirt or debris in or on the connector pins.

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

Dirty or damaged pins?
YES NO

Repair or replace the damaged engine harness, connector, or 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 019-202.
  • Replace the engine harness. Refer to Procedure 019-043.
  • Replace the fuel pressure sensor. Refer to Procedure 019-188.
 No Repair

Guided Step 2B – Check the circuit response.

Conditions

  • Turn keyswitch OFF
  • Disconnect the fuel pressure 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 119 active and Fault Code 118 inactive?
YES NO
No Repair No Repair

Guided Step 2C – Check the sensor supply voltage and return circuit.

Conditions

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

Action

  • Measure the voltage between the +5 VDC SUPPLY pin and the fuel pressure RETURN pin at the fuel pressure sensor connector of the engine harness.

Refer to the wiring diagram for connection pin identification.

4.5 to 5.25 VDC?
YES NO
No Repair No Repair

Guided Step 2D – Check the fault codes and verify sensor condition.

Conditions

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

Action

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

Fault Code 118 active?
YES NO

Replace the fuel pressure sensor. Refer to Procedure 019-188.

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 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 damage
  • Dirt or debris in or on the connector pins.

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

Dirty or damaged pins?
YES NO

Repair or replace the engine harness, connector or 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 3B – Check for an open circuit in the engine harness.

Conditions

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

Action

  • Measure the resistance between the ECM connector RETURN pin and the fuel pressure sensor connector RETURN pin.

Refer to the wiring diagram for connector pin identification.

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

Less than 10 ohms?
YES NO
No Repair

Repair or replace the engine harness.

  • 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 019-202.
  • Replace the engine 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 the engine harness from the ECM
  • Disconnect the fuel pressure sensor from the engine harness.

Action

  • Measure the resistance between the fuel pressure SIGNAL pin in the engine harness and all the other pins in the engine harness connector 1.
  • Measure the resistance between the fuel pressure SIGNAL pin in the engine harness connector 1 and all the other pins in the engine connector 2.

Refer to the wiring diagram for connector pin identification.

For general resistance measurement techniques, refer to Procedure 019-360, Resistance Measurement Using a Multimeter and Wiring Diagram.
SMALL | MEDIUM | LARGE

Greater than 100k ohms?
YES NO
No Repair

Repair or replace the engine harness, connector or 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 3D – Check for a pin to pin short circuit in the engine harness.

Conditions

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

Action

  • Measure the resistance between the fuel pressure +5 VDC SUPPLY pin in the engine harness connector 1 and all the other pins in the engine harness connector 1.
  • Measure the resistance between the fuel pressure +5 VDC SUPPLY pin in the engine harness connector 1 and all the other pins in the engine connector 2.

Refer to the wiring diagram for connector pin identification.

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

Greater than 1000 ohms?
YES NO
No Repair

Repair or replace the engine harness, connector or 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 3E – 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 118 inactive?
YES NO

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

Call for authorization prior to replacing the ECM.

Replace the ECM. 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, verify the fault code is inactive.

Fault Code 118 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 clear the inactive fault codes.

All fault codes cleared?
YES NO
No Repair No Repair
Repair complete
Appropriate troubleshooting charts
Last Modified:  06-Aug-2004
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