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P1403

Loss Of 5 Volts To EGR Sensor.

  • Dodge
  • Powertrain
  • Manufacturer code
  • Medium severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
4
AreaAuxiliary emission controls
03
FaultThe specific fault in that area

What it means

On Dodge vehicles P1403 means the powertrain control module has lost the 5 volt reference supply to the EGR sensor circuit. The module sees the reference voltage missing or out of range, so it cannot trust the EGR position or flow signal and sets the fault. Which sensor and wiring is involved depends on the model, engine and year.

Symptoms

  • Check engine light on
  • Rough idle or occasional stumbling at low speed
  • Slight hesitation or poor drive-away under light load
  • Pinging or detonation under load in some cases
  • Failed emissions test
  • Other 5 volt sensor codes stored at the same time

Possible causes

  • Short to ground or damage in the 5 volt reference wire feeding the EGR sensorlikely
  • Faulty EGR position or EGR flow sensor pulling the reference supply down internallylikely
  • Corroded, loose or pushed-out pins at the EGR sensor or valve connectorlikely
  • Another sensor on the shared 5 volt reference circuit shorted, dragging the supply downpossible
  • Chafed or heat-damaged harness near the EGR valve or exhaust manifoldpossible
  • Fault inside the powertrain control module reference supplyrare

How to diagnose

  1. Read all stored and pending codes and the freeze frame data, noting whether other 5 volt sensor codes are present
  2. Check the service information for which sensors share the 5 volt reference on this model and engine
  3. Inspect the EGR sensor, valve connector and harness for heat damage, chafing, corrosion and loose pins
  4. With the ignition on, measure the reference voltage at the EGR sensor connector against a good ground
  5. If the voltage is low, unplug the EGR sensor and recheck; if it recovers, suspect the sensor
  6. If it stays low, unplug other sensors on the shared reference one at a time to find a short
  7. Check the reference wire for continuity and for shorts to ground back to the module
  8. Clear the code and road test, watching the EGR sensor signal and reference voltage

How to fix

  • Repair or replace the damaged section of the 5 volt reference wiring
  • Replace the faulty EGR sensor or EGR valve assembly if the sensor is integral
  • Clean or repair the connector terminals, or replace the connector
  • Replace any other shorted sensor that is pulling the shared reference down
  • Replace or repair the powertrain control module only after wiring and sensors are proven good, following the manufacturer procedure

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but book it in soon as the EGR system may not work properly and driveability and emissions can suffer. Stop driving if it runs very roughly or other warning lights appear.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.

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