P006B Code: MAP Exhaust Pressure Correlation

Reviewed by

Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on June 5th, 2024

Reading Time: 3 minutes
Summary
  • DTC P006B stands for “MAP Exhaust Pressure Correlation,” and it’s logged when the PCM detects that the difference between the signals from the MAP sensor and the exhaust pressure sensor is beyond specification.
  • Code P006B could be caused by a faulty MAP sensor, faulty exhaust pressure sensor, and circuit issues.
  • Common indicators of code P006B include a lit check engine light, poor engine performance, and bad fuel mileage.

If you have run a code scan and you’re having trouble figuring out what a code P006B means, this short guide should help you get started on your diagnosis.

What Does the P006B Code Mean?

Diagnostic trouble code (DTC) P006B stands for “MAP Exhaust Pressure Correlation.” It is set when the powertrain control module (PCM) detects that the difference between the signals from the manifold absolute pressure (MAP) sensor and the exhaust pressure sensor is beyond specification.

P006B will only appear on vehicles with an exhaust pressure sensor that can be used for a rationality check with the MAP sensor.

If the PCM perceives that the difference between the signals from the manifold absolute pressure (MAP) sensor and the exhaust pressure sensor is beyond specification, the error code P006B may register.

The MAP sensor relays information about the amount of pressure present in the engine intake manifold to the PCM. The exhaust pressure sensor, on the other hand, tells the PCM about the amount of pressure in the exhaust manifold. If the PCM perceives that the difference between the signals from these two sensors is beyond specification, the error code P006B is logged.

For more information that can help you properly diagnose and fix P006B, read our technical discussion about intake manifold pressure.

A Quick Note about EBP (Exhaust Backpressure) Sensor

The exhaust gas pressure sensor or exhaust back pressure sensor is a very important component in the diesel particulate filter (DPF) regeneration process on some platforms, but it isn’t present on all. But modern diesel vehicles also use a MAP sensor and when one is compared to the other, code P006B may be output if they don’t correlate.

The exhaust gas pressure sensor or exhaust back pressure sensor is a very important component in the diesel particulate filter (DPF) regeneration process on some platforms, but it isn’t present on all.

Richard McCuistian, ASE Certified Master Automobile Technician

Note: The definition of code P006B may be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.

What are the Possible Causes of the P006B Code?

P006B is a generic code, so it can have several causes. Here are the most common:

  • Faulty exhaust pressure sensor
  • Faulty MAP Sensor
  • Circuit  issues
  • Vacuum leak
  • PCM failure

What are the Common Symptoms of the P006B Code?

You may notice the following symptoms if you drive a vehicle with a stored P006B trouble code:

How to Diagnose the P006B Code

To avoid potential engine complications, code P006B should be resolved immediately. Diagnosing this code can get tricky though, as it has several possible causes.

As a rule of thumb, always follow the diagnostic procedure specified by your vehicle’s manufacturer. This is because the process may differ per vehicle. For example, the steps for diagnosing a code P006B on a Ford may differ from the steps for testing a GM P006B code.

Refer to a vehicle-specific repair manual for the appropriate diagnostic strategy. If you’re not well-versed in auto repair, it would be best to leave the job to a mechanic.

Having excessive smoke coming from the exhaust is a common symptom of code P006B.

How to Fix the P006B Code

Like other OBD-II codes, there is no fixed solution for a P006B code. All vehicles are different, so you should always refer to your vehicle’s factory repair information before DIY-ing any repairs. 

Code P006B is a complicated code, so always consult a repair manual or repair database before attempting to resolve it. If you’re not that confident in your automotive repair skills, you should consider enlisting the help of a professional.

Products Mentioned in this Guide

About The Authors
Reviewed By Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Written By CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

Share
Published by
CarParts.com Research Team and Richard McCuistian, ASE Certified Master Automobile Technician