Failed EGR valve solenoid or stepper motor winding; Open or shorted wire in the EGR control circuit; Corroded or loose electrical connector at the EGR valve; Faulty PCM driver for the EGR circuit (rare but possible); Carbon buildup causing the valve to stick and draw excessive current; Damaged or chafed wiring harness near the EGR valve

DTC codes / GM codes / P1405

P1405 · GMEGR Valve Control Circuit

Q: What does code P1405 mean?

EGR Valve Control Circuit. P1405 on GM vehicles indicates that the powertrain control module (PCM) has detected an electrical fault in the exhaust gas recirculation (EGR) valve control circuit. The PCM monitors the circuit for expected voltage or current changes when commanding the EGR valve; when the feedback does not match the command, it sets this code. This is a circuit-level fault, not a performance code, so the valve may not be moving at all or the wiring may be compromised.

P1405 on GM vehicles indicates that the powertrain control module (PCM) has detected an electrical fault in the exhaust gas recirculation (EGR) valve control circuit. The PCM monitors the circuit for expected voltage or current changes when commanding the EGR valve; when the feedback does not match the command, it sets this code. This is a circuit-level fault, not a performance code, so the valve may not be moving at all or the wiring may be compromised.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyIntermediate

AreaAuxiliary emission controls

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Rough idle or stalling after the engine warms up
Slight decrease in fuel economy during normal driving
Engine ping or knock under light acceleration
Failed emissions test due to high oxides of nitrogen (NOx) levels
Intermittent hesitation or surge while cruising

Common causes, most likely first

Failed EGR valve solenoid or stepper motor winding
Open or shorted wire in the EGR control circuit
Corroded or loose electrical connector at the EGR valve
Faulty PCM driver for the EGR circuit (rare but possible)
Carbon buildup causing the valve to stick and draw excessive current
Damaged or chafed wiring harness near the EGR valve

How to diagnose and fix it

Inspect the EGR valve connector and wiring for corrosion, looseness, or damage; clean or repair as needed
Measure resistance of the EGR valve control solenoid and compare to specification
Check for battery voltage and ground at the EGR valve connector with the key on
Perform a bidirectional scan tool test to command the EGR valve open and closed while watching for proper movement
Check continuity and resistance of the control circuit between the PCM and EGR valve
If the circuit and valve test good, substitute a known-good EGR valve to rule out a sticking valve
If all else fails, diagnose the PCM driver circuit or replace the PCM as a last resort

What most technicians overlook on P1405

A sticking EGR valve due to carbon buildup can cause the control circuit to exceed current limits and set P1405, so always inspect and clean the valve passages before replacing electrical parts.
The EGR valve on many GM engines is difficult to access, and a chafed wire near the exhaust manifold is a common hidden cause that only appears when the engine is hot.
P1405 can be set by a weak battery or charging system issue that causes low voltage during EGR self-tests, so verify battery and charging system health first.
Some GM vehicles use a linear EGR valve with a position sensor; a faulty sensor can mimic a control circuit fault, so check live data for commanded versus actual position.
After repairs, the PCM may require a relearn procedure or several drive cycles before the code clears from history, so do not assume the fix failed if the light stays on briefly.

Can I keep driving with P1405?

You can usually drive with P1405, but avoid long trips or heavy loads until it is fixed because the engine may run less efficiently and emissions will be higher. If you notice rough running, stalling, or reduced power, have it diagnosed promptly to prevent further damage.

Tools that help

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Guidance is general and written for GM vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.