Too much exhaust back pressure can cause a number of issues. The classic signs of excessive back pressure include a lack of high-speed power, poor fuel economy, and even overheating. Anything that increases exhaust pressure in the engine increases heat. But there are instances when back pressure is needed to warm up your engine during a cold start.
The role of the exhaust pressure control valve is to control exhaust back pressure during cold start warm-up. This valve also opposes cylinder pressure from the engine. P0476 is a trouble code related to a fault in your exhaust pressure control valve. Know more about it through this article.
What Does a P0476 Code Mean?
Diagnostic trouble code (DTC) P0476 stands for “Exhaust Pressure Control Valve “A” Range/Performance. The P0476 code is set once the powertrain control module detects a discrepancy in the signal sent by the exhaust pressure control valve.
An exhaust pressure control valve is installed in the exhaust stream to generate heat in the form of back pressure in the exhaust to help with cold start warm-up. It can also counteract cylinder pressure coming from the engine cylinders through the exhaust, slowing the engine and the vehicle. This is particularly helpful during towing operations.
Under normal driving conditions, the P0476 code might mean that the incoming signal from the exhaust pressure sensor does not match the intake manifold pressure, ambient air pressure, or preprogrammed information. Depending on the vehicle manufacturer, this could be a mechanical or electrical circuit fault.
For more technical information that can help you better understand P0476, read our discussion about the exhaust backpressure system.
Note: The definition of code P0476 might be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.
What are the Common Causes of the P0476 Code?
- Exhaust pressure control valve malfunction
- Bad PCM
- Wiring problem
What are the Common Symptoms of the P0476 Code?
- Illuminated check engine light
- Lack of power
- Poor engine braking
- Cold engine warm-up time takes longer
How to Diagnose a P0476 Code
P0476 can be set in any vehicle that has an on-board diagnostic system. However, this does not suggest that there is a single diagnostic procedure that will work for all makes and models. If you lack the necessary technical knowledge, it is best to leave the job to a trusted mechanic.
How to Fix the P0476 Code
You’ll need the right tools and in-depth knowledge of engine repair to fix the underlying problem that set the P0476 code in your OBD system. If you don’t have the time or the necessary technical know-how for this type of repair, you may be better off taking your vehicle to a certified mechanic.
If you’re determined to find the fix yourself, we recommend consulting your vehicle’s repair manual or looking up vehicle-specific repair information from an online repair database.
About the Exhaust Backpressure System
Code P0476 is most typically used on second generation Ford 7.3L light vehicle diesel platforms. The backpressure control valve is driven by an oil piston built into the base of the turbocharger, and on the second generation 7.3L, a sensor mounted in a small tube connected to the exhaust is used to monitor the pressure.
This is primarily used to control exhaust back pressure during cold ambient temperatures to increase cab heat and decrease the amount of time needed to defrost the windshield. The powertrain control module (PCM) uses the measured exhaust back pressure, intake air temperature and engine load to determine the desired exhaust backpressure.
The pipe can become clogged with sludge and carbon, which can set additional codes, but this feedback is used to verify backpressure change when the turbocharger butterfly is commanded closed.
In the photo, a new sensor has been connected to compare static readings for diagnosis purposes. If the backpressure valve system malfunctions so that it remains closed all the time, engine power will be significantly reduced.
On the 6.0 Power Stroke, this system was no longer necessary due to the variable geometry turbocharger system, which included the backpressure increase function.
Where to Get a New Exhaust Pressure Control Valve for Your Vehicle
Why put up with the hassles that come with the DTC P0476 when you can clear the code with the right replacement parts? A malfunctioning exhaust pressure control valve is the usual culprit. If you’ve found that it’s what triggered the code in your case, you can count on CarParts.com to have a direct-fit replacement part for your ride.
We make sure to get all our auto parts from trusted manufacturers. Each item is hand-picked by professionals to guarantee quality, so you won’t have to worry about your new exhaust pressure control valve failing you any time soon.
Use our vehicle selector to start shopping for the parts you need. Use the search filters to narrow down the exhaust pressure control valves according to your preferred brand, price range, quantity, etc.
You won’t have to break the bank to get new parts either. Every item in our catalog is set at competitive prices. On top of that, our warehouses are strategically located all over the US to guarantee fast shipping.
Shop now to resolve the trouble code in no time!
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