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Electronic Control System Gas Plus Engines – FAULT CODE 512bgi

Throttle Plate Position Sensor Circuit – Shorted High

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Overview

CODE REASON EFFECT
Fault Code: 512
PID: P51
SPN: 51
FMI: 3
LAMP: Amber
SRT: 

Throttle Plate Position Sensor Circuit – Shorted High. High voltage detected at the Electronic Control Module (ECM).

Possible reduced performance.

Throttle Plate Position Sensor Circuit
SMALL | MEDIUM | LARGE

Circuit Description

The throttle plate position sensor is used by the electronic control module (ECM) to measure the percentage of throttle plate opening.

Component Location

The throttle plate position sensor is installed on top of the throttle body.

Shop Talk

Check to make sure that throttle linkage moves smoothly and freely.

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 3823995 – male Weather-Pack test lead.

Troubleshooting Steps

STEPS SPECIFICATIONS
STEP 1. Check the fault codes.  
  STEP 1A. Check for an inactive fault code. Fault Code 512 inactive?
STEP 2. Check the throttle plate position sensor and circuit.  
  STEP 2A. Inspect the throttle plate position sensor and connector pins. Dirty or damaged pins?
  STEP 2B. Check resistance of throttle plate position sensor. Resistance less than 4800 Ohms?
  STEP 2C. Check for an inactive fault code. Fault Code 512 inactive?
STEP 3. Check the engine control module and engine harness.  
  STEP 3A. Inspect the engine control module and engine harness connector pins. Dirty or damaged pins?
  STEP 3B. Check for a pin-to-pin short circuit in the engine harness. Greater than 100k ohms?
  STEP 3C. Check for an inactive fault code. Fault Code 512 inactive?
STEP 4. Clear the fault codes.  
  STEP 4A. Disable the fault code. Fault Code 512 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 INSITE™ electronic service tool.

Action

Check for an inactive fault code.

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

Fault Code 512 inactive?
YES NO

Inactive or intermittent fault code, refer to Procedure 019-362.

 No Repair

Guided Step 2 – Check the throttle plate position sensor and circuit.

Guided Step 2A – Inspect the throttle plate position sensor and connector pins.

Conditions

  • Turn keyswitch OFF
  • Disconnect the throttle plate position sensor from the engine harness.

Action

Inspect the engine harness and throttle posiition sensor connector pins for the following:

  • 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 sensor or engine harness connector.

Clean the connector and pins.

  • Repair the damaged harness, connector or pins if possible.
  • 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 throttle actuator. Refer to Procedure 019-121.
 No Repair

Guided Step 2B – Check resistance of throttle plate position sensor.

Conditions

  • Keyswitch in OFF position.
  • Disconnect the engine harness from throttle plate position sensor from the engine harness.
  • Throttle plate in the closed position.

Action

Check the resistance of the throttle plate position sensor.

  • Measure the resistance for throttle plate position sensor. Return to the throttle plate position sensor SIGNAL pin on the sensor.
  • The resistance should increase smoothly as the throttle is opened.

Resistance less than 4800 Ohms?
YES NO
No Repair

Replace the throttle plate position sensor. Refer to Procedure 019-085.

Guided Step 2C – 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 512 inactive?
YES NO

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

 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 engine harness connector 1 from the ECM.

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 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 engine control module connector 1 or the engine harness connector.

Clean the connector and pins.

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

  • 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-to-pin short circuit in the engine harness.

Conditions

  • Turn keyswitch OFF
  • Disconnect engine harness connector 1 and connector 2 from the engine control module.
  • Disconnect the throttle plate position sensor from the engine harness.

Action

Check for a pin-to-pin short circuit.

  • Measure the resistance between the throttle plate position sensor (+) pin in the engine harness engine control module engine connector 2 and all other pins in the engine connector 2.
  • Measure the resistance between the throttle plate position sensor (+) pin in the engine harness engine control module engine connector 2 and all other pins in the engine connector 1.
  • Measure the resistance between the throttle position SIGNAL pin in the engine harness engine control module connector 1 and all other pins in the engine connector 1.
  • Measure the resistance between the throttle position SIGNAL pin in the engine harness engine control module connector 1 and all other pins in the engine connector 2.

Use 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-pin short circuit on the throttle position sensor command (+) line for position signal line has been detected in the engine harness.

  • Repair or replace the engine harness.
  • Repair the harness. Refer to Procedure 019-204.
  • Replace the engine harness. Refer to Procedure 019-043.

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

Conditions

  • Connect all components
  • Turn keyswitch ON
  • Connect the 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 512 inactive?
YES NO

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

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

Disable the fault code.

  • Start the engine and let it idle for one minute.
  • Use INSITE™ electronic service tool to verify that the fault code is inactive.

Fault Code 512 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 the INSITE™ electronic service tool.

Action

Clear the inactive 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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