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Electronic Control System Gas Plus Engines – FAULT CODE 431 – Integrated Sensor Switch

Accelerator Pedal or Lever Idle Validation Circuit – Data Erratic, Intermittent or Incorrect.

Overview

CODE REASON EFFECT
Fault Code: 431
PID: S230
SPN: 558
FMI: 2/2
LAMP: Amber
SRT: 

Accelerator Pedal or Lever Idle Validation Circuit – Data Erratic, Intermittent or Incorrect. Voltage detected simultaneously on both idle validation and off-idle validation switches.

None.

Accelerator Pedal or Lever Idle Validation Circuit
SMALL | MEDIUM | LARGE

Circuit Description

The idle validation switch is used by the electronic control module (ECM) to indicate when the accelerator pedal or lever is released (on-idle or depressed (off-idle). The switch is adjusted during the pedal manufacturing process to switch from on-idle to off-idle at the correct accelerator pedal or lever position. The switch return is a shared return with other OEM cab switches.

Component Location

The integrated sensor switch is located on the accelerator pedal or lever assembly.

Shop Talk

  • This fault code is usually caused by an open circuit on either the idle validation on-idle or off-idle signal circuits, a loose connection, uncalibrated accelerator pedal or lever assembly, or mis-wired idle validation switch.
  • The integrated sensor switch has a different internal resistance specification (125 ohms) than the nonintegrated sensor switch.
  • When installing a new accelerator pedal or lever assembly, it must be calibrated before operating the engine. To calibrate, turn the keyswitch to the ON position and fully depress and release the pedal three times.

Cautions and Warnings

 WARNING 

On automotive applications, set the service brake using the trailer brake hand valve. Make sure there is enough air pressure to activate the brake pressure switch. Securely chock the wheels. Truck movement during troubleshooting can cause severe equipment damage, personal injury or death.
 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 3823993 – male Deutsch test lead
Part Number 3823996 – female Weather-Pack test lead.

Troubleshooting Steps

STEPS SPECIFICATIONS
STEP 1. Check the integrated sensor switch.  
  STEP 1A. Verify the integrated sensor switch is connected to the OEM harness. Integrated sensor switch is connected to the OEM harness?
  STEP 1B. Inspect the integrated sensor switch connector pins. Dirty or damaged pins?
  STEP 1C. Check the integrated sensor switch for an open circuit. Less than 125 ohms?
  STEP 1D. Check the integrated sensor switch for a short circuit from pin to pin. More than 100k ohms?
STEP 2. Check the wiring harnesses.  
  STEP 2A. Check the wiring harnesses for an open circuit. Greater than 4.0 VDC?
  STEP 2B. Inspect the engine harness and ECM connector pins. Dirty or damaged pins?
  STEP 2C. Check the harnesses for an open circuit. Less than 10 ohms?
  STEP 2D. Check the OEM harness switch return circuit. Less than 10 ohms?
  STEP 2E. Check for a pin to pin short circuit in the OEM harness. Greater than 100k ohms?
STEP 3. Clear the fault codes.  
  STEP 3A. Disable the fault code. Fault Code 431 inactive?
  STEP 3B. Clear the inactive fault codes. All fault codes cleared?

Guided Step 1 – Check the integrated sensor switch.

Guided Step 1A – Verify the integrated sensor switch is connected to the OEM harness.

Conditions

  • Turn keyswitch OFF

Action

  • Verify the integrated sensor switch is connected to the OEM harness.

Integrated sensor switch is connected to the OEM harness?
YES NO
No Repair

Connect the integrated sensor switch to the OEM harness. Refer to the OEM service manual.

Guided Step 1B – Inspect the integrated sensor switch connector pins.

Conditions

  • Turn keyswitch OFF
  • Disconnect the integrated sensor switch from the OEM harness.

Action

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

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, connector, 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 OEM harness. Refer to Procedure 019-071.
 No Repair

Guided Step 1C – Check the integrated sensor switch for an open circuit.

Conditions

  • Turn keyswitch OFF
  • Disconnect the integrated sensor switch from the OEM harness.

Action

  • Measure the resistance between the idle validation switch on-idle SIGNAL pin and switch RETURN pin in the integrated sensor switch connector with the pedal or lever released.
  • Measure the resistance between the idle validation switch off-idle SIGNAL pin and switch RETURN pin in the integrated sensor switch connector with the pedal or lever depressed.

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

Less than 125 ohms?
YES NO
No Repair

Refer to the OEM service manual.

Guided Step 1D – Check the integrated sensor switch for a short circuit from pin to pin.

Conditions

  • Turn keyswitch OFF
  • Disconnect the integrated sensor switch from the OEM harness.

Action

  • Measure the resistance between the idle validation switch on-idle SIGNAL pin and idle validation off-idle SIGNAL pin of the integrated sensor switch connector with the pedal or lever released and depressed.

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

More than 100k ohms?
YES NO
No Repair

Refer to the OEM service manual.

Guided Step 2 – Check the wiring harnesses.

Guided Step 2A – Inspect the wiring harnesses for an open circuit.

Conditions

  • Turn keyswitch OFF
  • Disconnect the integrated sensor switch from the OEM harness
  • Turn keyswitch ON.

Action

  • Measure the voltage from the idle validation switch on-idle SIGNAL pin on the integrated sensor switch connector of the OEM harness to the switch RETURN pin in the integrated sensor switch connector of the OEM harness.
  • Measure the voltage from the idle validation switch off-idle SIGNAL pin on the integrated sensor switch connector of the OEM harness to the switch RETURN pin in the integrated sensor switch connector of the OEM harness.

Refer to the circuit diagram or wiring diagram for connector pin identification.
SMALL | MEDIUM | LARGE

Greater than 4.0 VDC?
YES NO
No Repair No Repair

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

Conditions

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

Action

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

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 or engine harness connector.

Repair the damaged pins. Repair or replace the harness, connector, 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 OEM harness. Refer to Procedure 019-071.
 No Repair

Guided Step 2C – Check the harnesses for an open circuit.

Conditions

  • Turn keyswitch OFF.
  • Disconnect the engine harness from the ECM connector 2.
  • Disconnect the integrated sensor switch from the OEM harness.

Action

  • Measure the resistance of the idle validation on-idle SIGNAL wire in the wiring harnesses between the ECM connector and the integrated sensor switch connector.
  • Measure the resistance of the idle validation off-idle SIGNAL wire in the wiring harnesses between the ECM connector and the integrated sensor switch connector.

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

Less than 10 ohms?
YES NO
No Repair

Repair or replace the OEM 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 OEM harness. Refer to Procedure 019-071.

Guided Step 2D – Check the OEM harness switch return circuit.

Conditions

  • Turn keyswitch OFF
  • Disconnect the integrated sensor switch from the OEM harness.

Action

  • Measure the resistance of the switch RETURN wire in the OEM harness between the chassis ground and the integrated sensor switch connector.

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

Less than 10 ohms?
YES NO
No Repair

Repair or replace the OEM 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 OEM harness. Refer to Procedure 019-071.

Guided Step 2E – Check for a pin to pin short circuit in the OEM harness.

Conditions

  • Turn keyswitch OFF
  • Disconnect engine harness from the ECM connector 2
  • Disconnect the integrated sensor switch from the OEM harness.

Action

  • Measure the resistance between the idle validation switch on-idle SIGNAL pin in engine harness and all other pins in the ECM connector 1.
  • Measure the resistance between the idle validation switch on-idle SIGNAL pin in engine harness and all other pins in the ECM connector 2.
  • Measure the resistance between the idle validation switch off-idle SIGNAL pin in engine harness and all other pins in the ECM connector 1.
  • Measure the resistance between the idle validation switch off-idle SIGNAL pin in engine harness 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.
SMALL | MEDIUM | LARGE

Greater than 100k ohms?
YES NO
No Repair

Repair or replace the OEM 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 OEM harness. Refer to Procedure 019-071.

Guided Step 3 – Clear the fault codes.

Guided Step 3A – Disable the fault code.

Conditions

  • Connect all components
  • Connect INSITE™ electronic service tool.

Action

  • Turn the keyswitch ON and completely depress and release the accelerator pedal or lever three times.
  • Use INSITE™ electronic service tool to verify that Fault Code 431 is inactive.

Fault Code 431 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 steps
Last Modified:  03-Sep-2004
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