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Electronic Control System Gas Plus Engines – FAULT CODE 443

Accelerator Pedal Position Sensor Supply Voltage – Shorted Low

Overview

CODE REASON EFFECT
Fault Code: 443
PID: S221
SPN: 1043
FMI: 4
LAMP: Amber
SRT: 

Accelerator Pedal or Lever Position Sensor Supply Voltage Circuit – Voltage Below Normal, or Shorted to Low Source. Low voltage detected at the accelerator pedal position sensor.

Engine idles when the idle validation switch indicates idle and ramps up to a default set speed when the idle validation switch indicates off idle.

Accelerator Pedal or Lever Position Sensor Supply Voltage Circuit
SMALL | MEDIUM | LARGE

Circuit Description

The accelerator pedal position sensor sends a signal to the electronic control module (ECM), when the driver depresses the accelerator pedal, to determine the accelerator pedal position.

Component Location

The accelerator pedal position sensor is located on the accelerator pedal.

Shop Talk

  • Make sure there are no external circuits hooked into the accelerator pedal position sensor circuit and that there are no signs of tampering in the circuit.
  • If all the wiring and sensor checks are okay, replace the accelerator pedal position sensor and the idle validation switch circuit wires, between the accelerator pedal and ECM, with new wires. Run the wires through or around the bulkhead without using the bulkhead connector. Test the vehicle with the test wires in place. If the fault code goes away, replace the OEM harness.
  • Verify that the accelerator pedal position sensor wires are twisted together.

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 3823993 – male Deutsch test lead.

Troubleshooting Steps

STEPS SPECIFICATIONS
STEP 1. Check multiple fault codes.  
  STEP 1A. Check for an inactive fault code. Fault Code 443 inactive?
STEP 2. Check the sensors and sensor supply circuit.  
  STEP 2A. Inspect the accelerator pedal position sensor and connector pins. Dirty or damaged pins?
  STEP 2A-1. Check the circuit response.
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 and OEM harnesses. Greater than 100k ohms?
  STEP 3B-1. Check for a pin short circuit to ground.
  STEP 3C. Check for an inactive fault code. Fault Code 443 inactive?
STEP 4. Clear the fault codes.  
  STEP 4A. Disable the fault code. Fault Code 443 inactive?
  STEP 4B. Clear the inactive fault codes. All fault codes cleared?

Guided Step 1 – Check multiple fault codes.

Guided Step 1A – Check for an inactive fault code.

Conditions

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

Action

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

Fault Code 443 inactive?
YES NO
No Repair No Repair

Guided Step 2 – Check the sensors and sensor supply circuit.

Guided Step 2A – Inspect the accelerator pedal position sensor and connector pins.

Conditions

  • Turn keyswitch OFF
  • Disconnect the accelerator pedal position sensor from the OEM 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.

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

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, 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.
  • Refer to the OEM troubleshooting and repair manual.
 No Repair

Guided Step 2A-1 – Check the circuit response.

Conditions

  • Turn keyswitch OFF
  • Disconnect the accelerator pedal position sensor from the OEM harness
  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool.

Action

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

Fault Code 443 active?
YES NO
No Repair

A defective sensor has been detected.

Replace the accelerator pedal position sensor. Refer to the OEM troubleshooting and repair manual.

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 the engine harness connector 2 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.

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

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 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 a pin to pin short circuit in the engine and OEM harnesses.

Conditions

  • Turn keyswitch OFF
  • Disconnect engine harness connector 1 and connector 2 from the ECM
  • Disconnect the accelerator pedal position sensor from the OEM harness
  • Make sure all components to accelerator pedal position sensor supply are disconnected.

Action

  • Measure the resistance between the accelerator pedal position sensor SUPPLY pin in engine harness ECM connector 2 to all other pins in the engine connector 2.
  • Measure the resistance between the accelerator pedal position sensor SUPPLY pin in engine harness ECM connector 2 to all other pins in engine connector 1.

Refer 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 accelerator pedal position sensor supply line has been detected in the engine or OEM harnesses.

Troubleshoot each harness connected in series to determine which contains the shorted signal circuit.

Repair or replace the engine harness.

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

Guided Step 3B-1 – Check for a pin short circuit to ground.

Conditions

  • Turn keyswitch OFF
  • Disconnect engine harness connector 2 from the ECM
  • Disconnect the accelerator pedal position sensor from the OEM harness
  • Make sure all components to accelerator pedal position sensor supply are disconnected.

Action

  • Measure the resistance between the accelerator pedal position sensor SUPPLY pin in the engine harness ECM connector 2 and ground.

Refer 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 ground short circuit on the sensor supply number 1 line has been detected in the engine or OEM harnesses.

Troubleshoot each harness connected in series to determine which contains the shorted signal circuit.

Repair or replace the OEM or engine harnesses.

  • Repair the engine 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 INSITE™ electronic service tool.

Action

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

Fault Code 443 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 verify that the fault code is inactive.

Fault Code 443 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:  01-Sep-2004
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