Posted on by

Electronic Control System Gas Plus Engines – FAULT CODE 512gp

Throttle Plate Position Sensor Circuit – Shorted High

View Related Topic

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 ECM.

Possible reduced performance.

Electronic Throttle Control Actuator Circuit
SMALL | MEDIUM | LARGE

Circuit Description

The electronic control module (ECM) controls the throttle actuator, which is both an input and output device.

Component Location

The throttle actuator is located after the fuel housing and before the intake manifold inlet.

Shop Talk

The fault will light if the throttle actuator shorts to a high source on either the positive (+) throttle command or throttle position signal circuits.

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 actuator and circuit.  
  STEP 2A. Inspect the throttle actuator and connector pins. Dirty or damaged pins?
  STEP 2B. Check for an inactive fault code. Fault Code 512 inactive?
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 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

Refer to Procedure 019-362

No Repair

Guided Step 2 – Check the throttle actuator and circuit.

Guided Step 2A – Inspect the throttle actuator and connector pins.

Conditions

  • Turn keyswitch OFF
  • Disconnect the throttle actuator from the engine harness.

Action

Inspect the engine harness and throttle actuator 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.

Repair the damaged pins. Repair or replace the harness, or replace the throttle actuator, 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 harness. Use to Procedure 019-204.
  • Replace the harness. Use to Procedure 019-043.
  • Replace the throttle actuator. Use to Procedure 005-052 in the Troubleshooting and Repair Manual C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 and Procedure 005-052 in the Troubleshooting and Repair Manual B5.9G, B5.9 LPG, B Gas Plus and B LPG Plus Engines, Bulletin 3666164.
 No Repair

Guided Step 2B – 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
No Repair 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 connector 1 from the ECM.

Action

Inspect the engine harness and ECM 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 ECM connector 1 or the engine harness.

Repair the damaged pins. Repair or replace the 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 harness. Use to Procedure 019-204.
  • Replace the harness. Use 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 ICM.
  • Disconnect the throttle actuator from the engine harness.

Action

Check for a pin-to-pin short circuit.

  • Measure the resistance between the throttle actuator SUPPLY pin in the engine harness ECM connector 1 and all other pins in the engine connector 1.
  • Measure the resistance between the throttle actuator SUPPLY pin in the engine harness ECM connector 1 and all other pins in the engine connector 2.
  • Measure the resistance between the throttle position SIGNAL pin in the engine harness ECM connector 1 and all other pins in the engine connector 1.
  • Measure the resistance between the throttle position SIGNAL pin in the engine harness ECM 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 actuator command supply line or position signal line has been detected in the engine harness.

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 harness. Use to Procedure 019-204.
  • Replace the engine harness. Use 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
No Repair

Replace the ECM. Call for pre-authorization. Use 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
Avatar photo

Published by Jack

Hello, I'm Jack, a diesel engine fan and a blogger. I write about how to fix and improve diesel engines, from cars to trucks to generators. I also review the newest models and innovations in the diesel market. If you are interested in learning more about diesel engines, check out my blog and leave your feedback.