P04D2: EGR Temperature Sensor C Circuit Intermittent/Erratic

Exhaust gas recirculation (EGR) routes part of the exhaust back into the intake to lower combustion temperature and NOx. The code standard allows up to four EGR temperature sensors, A to D – for example before and after the cooler, or in the high- and low-pressure circuits; which is which depends on the maker. Sensor C is the third of them, usually an NTC whose low voltage means hot. P04D2 means brief excursions out of range or implausibly fast temperature jumps. FCA lists sensor C codes for its part 68142905A (Ram 2014 6.4 and 3.0 litre, Jeep and Dodge 3.6 Pentastar 2016) together with P040B, P0401 and P2457. GM checks sensor B in the same way with a jump test (40 of 50 samples). A Mack/Volvo truck bulletin names worn connector contacts at the EGR temperature sensor as a typical cause of wrong readings.

Symptoms

• Check engine light on, may come and go
• Usually no change in driving

Most likely causes

• Loose contact or fretting at the connector pins
• Wire chafing intermittently (vibration, heat)
• Sensor with an internal contact fault

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: medium
• It affects emissions.

What each character of P04D2 means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• 4: Emissions
• D2: Specific fault in that system

Frequently asked questions

Can I keep driving with code P04D2?

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 P04D2?

The most common causes are: loose contact or fretting at the connector pins; wire chafing intermittently (vibration, heat); sensor with an internal contact fault.

Related codes

• P04CEEGR Temperature Sensor C Circuit
• P04CFEGR Temperature Sensor C Circuit Range/Performance
• P04D0EGR Temperature Sensor C Circuit Low
• P04D1EGR Temperature Sensor C Circuit High
• P040EEGR Temperature Sensor A Circuit Intermittent/Erratic
• P041EEGR Temperature Sensor B Circuit Intermittent/Erratic

Sources

• static.nhtsa.gov: MC 10069340 0335
• static.nhtsa.gov: MC 10209606 9999
• static.nhtsa.gov: MC 10147500 9999

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.