Diesel Forum - TheDieselStop.com - Reply to Topic
6.7L Power Stroke Engine and Drivetrain Discussion of the 6.7L Power Stroke diesel engine and drivetrain in the 2011-Up Super Duty trucks. No gas engine discussion allowed except on transmissions and drivetrain that pertain to all models. Please confine discussion of topics in this forum to those items that are specific to the 6.7L Power Stroke engine.

Thread: DTC P026A. '2011 F250 6.7L Turbo Diesel Reply to Thread
Send Trackbacks to (Separate multiple URLs with spaces) :
Post Icons
You may choose an icon for your message from the following list:

Register Now

In order to be able to post messages on the Diesel Forum - TheDieselStop.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


  Additional Options
Miscellaneous Options

  Topic Review (Newest First)
03-08-2019 12:19 PM
ford_doctor The 6.7L turbocharger is cooled by the primary (engine) cooling system.
05-07-2018 07:43 AM
Jesse C110700 Larrgh // ford_doctor ...Thanks for the detailed description. I have checked and have no Leakes. However I was able to put a full container of coolant in the secondary reservoir. Now it's back to the cold fill line. I've deleted the DTC and will drive it today to work. I'm hoping that this is the cause. Not TOO worried about a coolant leak given the fact that I had one recently and a it was repaired. However, it was one of the coolant lines for the turbo. I'm not sure, without looking, what cooling system that is. Geez these new diesels are far more complicated than the old Army CAT I'm used to working on. Gone are the days of simplicity.

Thanks again!

05-06-2018 10:54 AM
Originally Posted by Jesse C110700 View Post
P026A - Charge Air Cooler Efficiency Below Threshold.

Check the coolant level in the secondary cooling system reservoir...
05-06-2018 08:35 AM
larrgh Charge air cooler is the inter cooler.

Charge Air Cooler Monitoring

The 6.7L engine is equipped with an air to water charge air intercooler. The CAC is on a secondary coolant loop, independent from the main engine coolant system. The temperature at the outlet of the cooler is measured as TCACDs, however the temperature going into the cooler is modeled.

To detect a CAC under cooling situation, the efficiency of the cooler is modeled at various speeds and airflows via a 3d speed/airflow multiplier table, providing a modeled cooler out temperature. Cooler efficiency * compressor out temperature = modeled cooler out temp. This modeled cooler out temp is then compared to the measured coolant out temp, if the difference is less than a threshold curve or greater than a threshold, a fault is detected and a P code is set.

Charge Air Cooler Monitor:

DTCs P026A - Charge Air Cooler Efficiency Below Threshold
P007E - Charge Air Cooler Temperature Sensor Intermittent/Erratic (Bank 1)

Monitor Execution Continuous

Monitor Sequence None

Sensors OK ECT, MAP, MAF

Typical Monitoring Duration 4 seconds for fault detection

Have you checked to see if you have a tube going to and from the inter cooler that is leaking? The 'cold air' return tube is know to rupture. Many install an aftermarket CAC return tube. I installed the kit from Rudy's. It is also possible the inter cooler is leaking.
05-06-2018 07:34 AM
Jesse C110700
DTC P026A. '2011 F250 6.7L Turbo Diesel

I'm starting to reconsider my diesel purchase. It seems like every month I have some little DTC that pops up. The truck runs great but I want to stay on top of these things and it's frustrating. I no more than corrected a faulty EGT sensor and now this code:

P026A - Charge Air Cooler Efficiency Below Threshold.

1. I want the best DIY Repair manual! Recommendations please!!
2. Can anyone tell me where the darn sensor is for the air charge cooler?
3. What would be my best approach to ridding myself of all these DTCs? I mean would bulletproofing do the trick?

If I wasn't bald, I'd pull out a few strands right about now.

Rant over.......Jess:

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

For the best viewing experience please update your browser to Google Chrome