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Electronic Control System Gas Plus Engines – FAULT CODE 135 – B and C Gas Plus

Engine Oil Pressure Sensor Circuit – Shorted High

Overview

CODE REASON EFFECT
Fault Code: 135
PID: P100
SPN: 100
FMI: 3
LAMP: Amber
SRT: 

Oil Pressure Sensor Circuit – Voltage Above Normal, or Shorted to High Source. High signal voltage detected on the engine oil pressure sensor pin at the ECM.

None on performance. No engine protection for oil pressure.

Engine Oil Pressure Sensor Circuit
SMALL | MEDIUM | LARGE

Circuit Description

The engine oil pressure/temperature sensor is used by the electronic control module (ECM) to monitor the lubricating oil pressure. The ECM monitors the voltage on the signal pin and converts this to a pressure value. The oil pressure value is used by the ECM for the engine protection system.

Component Location

The oil pressure/temperature sensor is located in the block, beneath the ECM.

Shop Talk

  • Does the fault occur only in cold weather? If so, allow the oil to warm up and see if the fault goes inactive.
  • Engine operating in altitudes above 5000 feet with auxiliary oil filtering devices can experience low oil pressure faults at idle conditions.

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 appropriate breakout cable when taking a measurement.
 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
Part Number 3162898 – breakout cable.

Troubleshooting Steps

STEPS SPECIFICATIONS
STEP 1. Check the fault codes.  
  STEP 1A. Check for 386 fault codes. Fault Code 386 active?
  STEP 1B. Check for an inactive fault code. Fault Code 135 inactive?
STEP 2. Check the oil pressure sensor and circuit.  
  STEP 2A. Inspect the oil pressure sensor and connector pins. Dirty or damaged pins?
  STEP 2B. Check the circuit response. Fault Code 141 active and Fault Code 135 inactive?
  STEP 2C. Check the sensor supply voltage and return circuit. 4.5 to 5.25 VDC?
  STEP 2D. Check for fault codes and verify sensor condition. Fault Code 135 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 100k ohms?
  STEP 3E. Check for an inactive fault code. Fault Code 135 inactive?
STEP 4. Clear the fault codes.  
  STEP 4A. Disable the fault code. Fault Code 135 inactive?
  STEP 4B. Clear the inactive fault codes. All fault codes cleared?

Guided Step 1 – Check the fault codes.

Guided Step 1A – Check for 386 fault codes.

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 135 inactive?
YES NO
No Repair No Repair

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

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

Conditions

  • Turn keyswitch OFF
  • Disconnect the oil pressure 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

A defective connection has been detected in the sensor or harness connector.

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

Guided Step 2B – Check the circuit response.

Conditions

  • Turn keyswitch OFF
  • Disconnect the oil 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 141 active and Fault Code 135 inactive?
YES NO
No Repair No Repair

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

Conditions

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

Action

  • Measure the voltage between the 5 Volt SUPPLY pin and the oil pressure RETURN pin on the oil pressure sensor connector of the engine harness.

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 oil 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 135 active?
YES NO

A defective sensor has been detected.

Replace the oil pressure sensor. Refer to Procedure 019-155 or 019-066.

 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 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 1 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 3B – Check for an open circuit in the engine harness.

Conditions

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

Action

  • Measure the resistance between the ECM connector 1 RETURN pin and the oil pressure sensor connector RETURN pin.

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

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

Less than 10 ohms?
YES NO
No Repair

An open circuit 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 019-202.
  • 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 engine harness from the ECM
  • Disconnect the oil pressure sensor from the engine harness.

Action

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

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

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

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 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 3D – Check for a pin to pin short circuit in the engine harness.

Conditions

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

Action

  • Measure the resistance between the oil pressure 5 Volt SUPPLY pin in engine harness connector 1 and all other pins in the ECM connector 1.
  • Measure the resistance between the oil pressure 5 Volt SUPPLY pin in engine harness connector 1 and all other pins in the ECM connector 2.

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

For general resistance measurement techniques, refer to the 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 SUPPLY 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 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 135 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 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 135 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:  17-Aug-2004
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