P04D2 code meaning
EGR Temperature Sensor C Circuit Intermittent/Erratic
Powertrain system Generic code P04xx codes Check engine light
What P04D2 means
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.
P04D2 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 1.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P04D2
- Check engine light on, may come and go
- Usually no change in driving
Common causes of P04D2
- Most likelyLoose contact or fretting at the connector pins
- PossibleWire chafing intermittently (vibration, heat)
- PossibleSensor with an internal contact fault
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
EGR temperature sensor cSensor wiringEngine control module
What each part of P04D2 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| D2 | The exact fault in that area. |
What to do next
- Note P04D2 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P04D2
What does P04D2 mean?
P04D2 means "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. It is a generic code, so it means the same on every make.
Is it safe to drive with P04D2?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P04D2 fail an emissions test?
Yes, it can. P04D2 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P04D2 to fix?
Difficulty: medium. A typical repair takes 0.5 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P04D2 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.