2012 Ram 2500 6.7 Exhaust Brake release/deactivate inputs or parameters

Hi, guys,

Lurking forums for awhile as I learn. Have a question and hoping some of you fine, knowledgable folk, might have an answer.

Working on a customers truck that has been deleted and tuned with a switch from another shop, and have replaced a stock turbo (not much choice under parts warranty), and are experiencing an issue with the Exhaust Brake not deactivating under higher speeds. It will deactivate and release finally, decellerating to about 20 mph from a few data logs with a Snap-on tool. Trying to find what inputs are used to deactivate and release the exhaust brake (Accel pedal position should release it, but it does not) and at what values are used as it determines this strategy to release the exhaust brake.

From the limited service information I have available, and operation manual, this should use the accel pedal position, and when it sees fuel delivery drop to 0%, to release. However, the fuel delivery seems to stay above the 5k psi range. Hope I'm tying this together well enough into words.

Low speed Exhaust brake operation seems fine, and automatically engages and releases the exhaust brake cruising around with in town speed limits.

Highway is different.

Trying to find what's keeping it on. Any help is awesome.

Thank you!

I have zero clue what your asking.

The exhaust brake operates when throttle is at zero and the torque converter is locked and the engine rpm is above 1200rpm. So if you are driving around at slow speeds below 4th gear the converter will be unlocked and you will get no exhaust brake. If however you are at higher speeds with the converter locked and you start to manually downshift with the tap controls it will keep the converter locked down until 2nd gear to aprox 1200rpm.

Thank you for your response! Yeah, sorry if I didn't get the words together right.

This truck happened to be a manual (which I failed to state, sorry!), and had also been configured to show clutch state as "yes" at all times.

I did end up narrowing it down to watching Desired VGT, Commanded VGT, and Turbo position *autozeroed*, and verified that getting back into the throttle at highway speeds the desired and commanded % would drop after an exhaust brake event, but the turbo position stayed at about 93% until the vehicle slowed to under 20mph.
After talking with the turbo remanufacturer, they informed us of outsourcing their actuators on these and having reported issues.

Thank you for your time and response!

As an update,

This took three turbos to finally get a correctly working actuator from this reman company. Out of the box with a Delphi tag on the working actuator, so look out for it!