P04D0: EGR Temperature Sensor C Circuit Low

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. P04D0 means its signal voltage is below the lower limit – extremely hot, or more often the signal line shorted to ground or the sensor shorted. 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. No threshold is published for sensor C; for sensor B Ford diesels use below 0.19 V and GM diesels below 164 Ω.

Symptoms

• Check engine light on
• Usually no change in driving (EGR on a substitute value or off)
• Possibly EGR flow or cooler codes (P0401, P2457)

Most likely causes

• Signal line shorted to ground (chafed hot harness)
• Sensor shorted internally
• Moisture or corrosion in the connector
• Engine module input

What to check, in order

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

1. Check the connector and any vacuum hoses
2. With the connector unplugged, check whether the signal wire is making contact with ground.
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 P04D0 means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• 4: Emissions
• D0: Specific fault in that system

Frequently asked questions

Can I keep driving with code P04D0?

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 P04D0?

The most common causes are: signal line shorted to ground (chafed hot harness); sensor shorted internally; moisture or corrosion in the connector.

Related codes

• P04CEEGR Temperature Sensor C Circuit
• P04D1EGR Temperature Sensor C Circuit High
• P04CFEGR Temperature Sensor C Circuit Range/Performance
• P04D2EGR Temperature Sensor C Circuit Intermittent/Erratic
• P040CEGR Temperature Sensor A Circuit Low
• P041CEGR Temperature Sensor B Circuit Low

Sources

• static.nhtsa.gov: MC 10069340 0335
• static.nhtsa.gov: MC 10209606 9999
• fordservicecontent.com: obd summary diesel 2023

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.