Faulty EGR valve with a failed integral pintle position sensor; Wiring damage, chafing or open or short circuit in the position sensor signal, reference or ground wires; Corroded, loose or damaged connector at the EGR valve or control unit; Carbon build-up causing the pintle to stick or give an erratic position reading; Fault with the sensor reference voltage or ground supply from the control unit; Internal fault in the engine control unit.

P1406

EGR Valve Pintle Position Circuit.

Plymouth
Powertrain
Manufacturer code
Medium severity

How this code is built

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

What it means

On a Plymouth, P1406 means the engine control unit has detected a fault in the EGR valve pintle position circuit. The control unit monitors the signal from the position sensor on the EGR valve and sets the code when the voltage is out of the expected range or does not match what it has commanded. The EGR system can then no longer be controlled accurately.

Symptoms

Malfunction indicator lamp on
Rough or unstable idle
Hesitation or surging under light load
Slight pinging or knocking under acceleration
Possible failed emissions test
Occasional stalling at idle

Possible causes

Faulty EGR valve with a failed integral pintle position sensorlikely
Wiring damage, chafing or open or short circuit in the position sensor signal, reference or ground wireslikely
Corroded, loose or damaged connector at the EGR valve or control unitlikely
Carbon build-up causing the pintle to stick or give an erratic position readingpossible
Fault with the sensor reference voltage or ground supply from the control unitpossible
Internal fault in the engine control unitrare

How to diagnose

Read the stored codes and freeze frame data to see engine load, speed and temperature when the fault set, and note any other related codes
Visually inspect the EGR valve, its connector and the wiring harness for heat damage, chafing, corrosion or loose pins
Check the EGR valve for carbon build-up and free movement of the pintle, following the procedure for the specific model and engine
Using live data, compare the commanded and actual EGR position and see whether the reading is stuck, erratic or out of range
Check the reference voltage, signal and ground at the EGR valve connector against the manufacturer's specification for that engine
Test the wiring between the valve and control unit for continuity, short to ground and short to voltage
Check the integrity of the sensor and valve resistance values against the model-specific specification
Clear the code after repair and road test to confirm it does not return

How to fix

Repair or replace damaged wiring and fix any open or short circuits
Clean or replace corroded or damaged connectors and terminals
Replace the EGR valve if the position sensor or pintle is faulty
Carefully clean a carbon-fouled valve and its passages if it is serviceable, then recheck the readings
Restore correct reference voltage or ground supply if the fault lies in the supply circuit
Diagnose and, only if proven faulty, repair or replace the control unit

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but have it checked soon as poor running and increased emissions are likely. Avoid prolonged driving if it is pinging, stalling or running roughly.

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