P041E: EGR Temperature Sensor B Circuit Intermittent/Erratic

Exhaust gas recirculation (EGR) routes part of the exhaust back into the intake to lower combustion temperature and NOx. EGR temperature sensor B is the second temperature sensor in the EGR path; on GM diesels it sits before the cooler, on Ford diesels after it. P041E means its signal jumps. GM's diesels of 2016–18, the only documented users, set it when the measured resistance changes by more than 25 Ω between two samples 100 ms apart – faster than any real temperature change, so a loose contact or cracked sensor is the cause (40 of 50 samples, MIL after two trips). Dependent checks such as EGR cooler efficiency are then suspended.

Symptoms

• Check engine light on, may come and go
• Usually no noticeable symptom
• Further EGR temperature or cooler checks suspended

Most likely causes

• Loose contact or corrosion at the sensor connector
• Harness chafed or broken (heat at the EGR pipe)
• Sensor cracked internally (thermal cycling)
• Engine module or ground connection

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the connector and any vacuum hoses
2. Gently move the wiring with the engine running and watch whether the reading changes.
3. Use live data to compare the commanded opening with the actual opening
4. Clean the valve and passages if they are clogged with carbon
5. Test the actuator with the scanner
6. Replace the valve if it still does not follow the command after cleaning

Good to know

• Repair difficulty: easy
• It affects emissions.

What each character of P041E means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• 4: Emissions
• 1E: Specific fault in that system

Frequently asked questions

Can I keep driving with code P041E?

You can normally drive in moderation, but get it repaired soon: if the valve is stuck open, the engine may idle very poorly.

What causes code P041E?

The most common causes are: loose contact or corrosion at the sensor connector; harness chafed or broken (heat at the EGR pipe); sensor cracked internally (thermal cycling).

Related codes

• P041AEGR Temperature Sensor B Circuit
• P041BEGR Temperature Sensor B Circuit Range/Performance
• P041CEGR Temperature Sensor B Circuit Low
• P041DEGR Temperature Sensor B Circuit High
• P040EEGR Temperature Sensor A Circuit Intermittent/Erratic
• P040FEGR Temperature Sensor A/B Correlation

Sources

• gsi.ext.gm.com: 18OBDG04 Engine Diagnostics
• gsi.ext.gm.com: 16OBDG04 Engine Diagnostics
• gsi.ext.gm.com: 17OBDG04 Engine Diagnostics
• law.cornell.edu: 13 CCR 1968.2

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.