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Electronic Control System Gas Plus Engines – FAULT CODE 337

Idle Speed Control Valve Circuit – Shorted Low

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Overview

CODE REASON EFFECT
Fault Code: 337
PID: S19
SPN: 634
FMI: 4
LAMP: Amber
SRT: 

Idle Speed Control Valve Circuit – Shorted Low

Low idle speed will be lower than normal. Engine can possibly die.

Idle Speed Control Valve Circuit – Shorted Low
SMALL | MEDIUM | LARGE

Circuit Description

The idle speed control valve is a bypass valve that is used to control idle speed under certain load conditions by the electronic control module
(ECM). The ECM uses this valve to regulate the air or fuel mixture flow at idle condition.

Component Location

The idle speed control valve is located on the side of the throttle body.

Shop Talk

The idle speed control valve only operates 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.

Troubleshooting Steps

STEPS SPECIFICATIONS
STEP 1. Check the fault codes.  
  STEP 1A. Check for inactive fault codes. Fault Code 337 inactive?
STEP 2. Check the idle speed control valve and circuit.  
  STEP 2A. Inspect the idle speed control valve and connector pins. Dirty or damaged pins?
  STEP 2B. Check for an open circuit in the idle speed control valve. 6 to 14 ohms?
  STEP 2B-1. Check for a short to ground in the idle speed control valve.
  STEP 2C. Check the idle speed control valve supply voltage, supply line and return circuit. Greater than 3-VDC?
STEP 3. Check the engine control module and engine harness.  
  STEP 3A. Inspect engine control module 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 337 inactive?
STEP 4. Clear the fault code.  
  STEP 4A. Disable the fault code. Fault Code 337 inactive?
  STEP 4B. Clear the inactive fault codes. All fault codes cleared?

Guided Step 1 – Check the fault codes.

Guided Step 1A – Check for inactive fault codes.

Conditions

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

Action

Check for an inactive fault code.

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

Fault Code 337 inactive?
YES NO

Inactive or Intermittent fault code, refer to Procedure 019-362

No Repair

Guided Step 2 – Check the idle speed control valve and circuit.

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

Conditions

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

Action

Inspect the engine harness and idle speed control valve connector pins for the following:

  • 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.

Clean the connector and pins.

Repair the damaged harness, connector, or pins if possible.

Refer to Procedure 019-204.

Refer to Procedure 019-043.

Refer to Procedure 019-104.

 No Repair

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

Conditions

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

Action

Check the idle speed control valve resistance.

  • Measure the resistance between the idle speed control valve SUPPLY pin and the idle speed control valve RETURN pin at idle speed control valve connector.

Refer to circuit description or circuit diagram for connector pin identification.

6 to 14 ohms?
YES NO
No Repair

Replace the idle speed control valve.

Refer to Procedure 019-104.

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

Conditions

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

Action

Check for a idle speed control valve output short to ground.

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

Use the wiring diagram for connector pin identification.

Greater than 100K ohms?
YES NO
No Repair

Replace the idle speed control valve.

Refer to Procedure 019-104.

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

Conditions

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

Action

Check the idle speed control valve supply voltage and return circuit.

  • Measure the voltage between the idle speed control valve output pin and the idle speed control valve RETURN pin at the idle speed control valve connector of the engine harness.

Greater than 3-VDC?
YES NO
No Repair No Repair

Guided Step 3 – Check the engine control module and engine harness.

Guided Step 3A – Inspect the engine control module and engine harness connector pins.

Conditions

  • Turn keyswitch OFF.
  • Disconnect the engine harness connectors 1 from the engine control module.

Action

Inspect the engine harness and engine control module connector 1 pins for the following:

  • 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, refer to Procedure 019-361

Dirty or damaged pin?
YES NO

A defective connection has been detected in the engine control module connector 1 or engine harness connector.

Clean the connector and pins.

Repair the damaged harness, connector, or pins, if possible.

Refer to Procedure 019-204.

Refer to Procedure 019-043.

 No Repair

Guided Step 3B – Check for a pin short circuit to ground.

Conditions

  • Turn keyswitch OFF.
  • Disconnect the engine harness connectors 1 from the engine control module.
  • Disconnect the idle speed control valve from the engine harness.

Action

Check for a pin to ground short.

  • Measure the resistance between the engine idle speed control valve output pin in the engine harness engine control module engine connector 1 and ground.

Use circuit art 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 100K ohms?
YES NO
No Repair

A pin to ground short circuit on the idle speed control valve output line has been detected in the engine harness.

Repair or replace the engine harness.

Refer to Procedure 019-204.

Use Procedure 019-043

Guided Step 3C – Check for an a pin-to-pin short circuit in the engine harness.

Conditions

  • Turn keyswitch OFF.
  • Disconnect the engine harness connectors 1 and connector 2 from the engine control module.
  • Disconnect the idle speed control valve from the engine harness.

Action

Check for a pin-to-pin short.

  • Measure the resistance between the idle speed control valve SUPPLY pin in the engine harness engine control module engine connector 1 and all other pins in the engine connector 1.
  • Measure the resistance between the idle speed control valve SUPPLY pin in the engine harness engine control module engine connector 1 and all other pins in the engine connector 2.

Refer to circuit description or circuit 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 idle speed control valve SUPPLY line has been detected in the engine harness.

Repair or replace the engine harness.

Refer to Procedure 019-204.

Refer to Procedure 019-043

Guided Step 3D – Check for an inactive fault code.

Conditions

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

Action

Check for the appropriate circuit response after 30 seconds.

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

Fault Code 337 inactive?
YES NO

None. The removal reinstallation of the connector corrected the failure.

Call for pre-authorization. Replace the engine control module.

Use Procedure 019-031.

Guided Step 4 – Clear thee fault codes.

Guided Step 4A – Disable the fault code.

Conditions

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

Action

Disable the fault code.

  • Use INSITE™ electronic service tool to verify the fault code is inactive.

Fault Code 337 inactive?
YES NO
No Repair

Return to the troubleshooting steps or contact a local Cummins Authorized Repair location if all steps have been completed and rechecked.

Guided Step 4B – Clear the inactive fault codes.

Conditions

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

Action

Clear the inacrive fault codes.

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

All fault codes cleared?
YES NO
No Repair

Troubleshoot any remaining active fault codes.
Repair Complete
Appropriate troubleshooting steps
Last Modified:  07-Dec-2004
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