P049E EGR B control position exceeds learning limit

OBD-II DTC Datasheet

Exhaust Gas Recirculation Control Position B Exceeds Teach Limit

What does this mean?

This is a generic transmission diagnostic trouble code (DTC) and is commonly applied to OBD-II vehicles that have an Exhaust Gas Recirculation (EGR) system. This may include, but is not limited to, vehicles from Dodge / Ram (Cummins), Chevy / GMC (Duramax), Honda, Jeep, Hyundai, etc.

Although general, the exact repair steps may vary depending on the model year, make, model, and transmission configuration.

If your OBD-II equipped vehicle has stored the code P049E, it means that the powertrain control module (PCM) has detected a malfunction in a specific test position of the downward exhaust gas recirculation (EGR) valve. B refers to a specific position of the down EGR valve.

The exhaust gas recirculation step-down valve system is designed to feed a portion of the exhaust gases back into the intake manifold in increments so that they can be burned a second time. This process is critical to reducing the amount of nitrous oxide (NOx) particles that are released into the atmosphere as a side effect of internal combustion and diesel engine operation. NOx is believed to be a contributor to ozone depletion from exhaust emissions. NOx emissions from vehicles in North America are subject to federal regulation.

The learning limit is a programmed degree that reflects the minimum and maximum parameters that a certain position (B) of the EGR step-down valve can adapt to. If the PCM detects that the actual EGR valve position is outside of these parameters, a P049E code will be stored and a malfunction indicator lamp (MIL) may come on. In some vehicles, it takes several ignition cycles (with failure) to activate the MIL.

What is the severity of this DTC?

Since the P049E code is related to the EGR system, it should not be considered serious.

What are some of the symptoms of the code?

Symptoms of a P049E DTC may include:

Most likely, there will be no symptoms with this code.
Slightly reduced fuel efficiency
Possible handling issues

What are some of the common causes for the code?

Reasons for this P049E EGR code may include:

Defective exhaust gas recirculation valve
Exhaust gas recirculation sensor defective
Bad PCM or PCM programming error

What are some of the P049E troubleshooting steps?

I usually start my diagnosis by locating the vehicle's diagnostic connector and retrieving all stored codes and associated data. I would write all this information down in case I need it as my diagnosis progresses. Then I would test drive the car to see if the code resets immediately.

By searching the Vehicle Technical Service Bulletins (TSB) for entries that match the vehicle, stored codes, and displayed symptoms, you can find a solution to your (potentially difficult) diagnosis. Since TSB records are sourced from thousands of repair technicians, they often contain very useful details.

If the P049E is saved after clearing the codes, I will have access to a diagnostic scanner, a digital volt / ohmmeter (DVOM), and a reliable source of vehicle information.

I would now perform a visual inspection of the EGR valve and all associated wiring and connectors. Focus on wire harnesses that are routed near hot exhaust components and jagged edges often associated with exhaust shields.

NOTE: Disconnect all related controllers from the circuit before testing resistance / continuity with the DVOM.

Using the wiring diagrams and connector pinouts located in your vehicle information source, test each individual exhaust gas recirculation valve (with DVOM) connector circuit for a signal. It may be necessary to manually activate the EGR system using a scanner, as most systems require a set speed before automatic activation can occur. Circuits that do not meet manufacturer's specifications will need to be traced back to their source (usually a PCM connector) and re-tested. If no output signal from the PCM is found, suspect a faulty PCM or a PCM programming error. Instead, repair or replace open / short circuits as needed.

Use the DVOM to test the actual EGR valve and built-in sensors if all circuits are within manufacturer's specifications. Your vehicle information source will again provide information to test this part. If the exhaust gas recirculation lowering valve and all (integrated) sensors do not meet manufacturer's specifications, suspect it is defective.

This code should only be displayed on vehicles equipped with an exhaust gas recirculation lowering valve.

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