P040D
EGR Temperature Sensor A Circuit High
EGR temperature sensor A above upper plausibility — open signal or short to B+. EGR mixes inert exhaust into intake to lower combustion peak temperature — too little raises NOx, too much causes misfires and rough running.
EGR temperature sensor A above upper plausibility — open signal or short to B+. EGR mixes inert exhaust into intake to lower combustion peak temperature — too little raises NOx, too much causes misfires and rough running.
Common causes
- high
Open signal line
One of the most commonly reported causes for this code — check this first.
Typical part cost: $70-440
- low
Connector pins corroded - high contact resistance
Less common, but worth ruling out after the more likely causes.
Typical part cost: $70-440
See all causes + fix costs
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does P040D mean?
P040D means "EGR Temperature Sensor A Circuit High". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.
What are the most common causes of P040D?
open signal line; connector pins corroded - high contact resistance; supply wire pinched against b+ source — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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