Engine Power Is Reduced - Ongoing Issue, Updates throughout thread.

[Just Fishing]

We have had some cooler weather, it is not doing it nearly as frequently. Specifically when it’s cold – cold for Florida under 60° – it will do it every few days.

I put the factory tune back on the ECM and the TCM end still getting the error. It comes up and says “engine power is reduced “and then disappears. No codes. However I’m getting a ton of fault codes. Nothing that illuminates the malfunction indicator lamp

Only real experience i have with this is when i was playing around with different tunes on my 6.0 swap.
One of the fields i copied was for the throttle body.
it gave me a clear "permeant error" for the ECM

Turned out to be an issue with the throttle body that i have installed not being compatible with the settings from another ecm/throttle body.

Apparently i could have bricked my ECM doing it... I got lucky!

Where I'm going with this, weird shit can happen with a failing part.
Sounds like the only thing you haven't changed out would be the ECM itself.

Junkyard near you?
Talk to blackbear about what it would take to swap the vin into a replacement ecm?

 

[Doubeleive]

here's my thoughts on things it could be
1. there is short in the harness or a module (high speed lan)
2. ecm is cooked (heating up and shorting)
3. fuse box cracked (heating up and loosing contacts)
4. bcm fault same (gets warm shorts)
for a couple hours of dealer level tech work with a scope they can probably find the source and be done with it. Regardless of whether they quote you a high price to "fix it" all you really need is the diagnostic done. I had some weird stuff going on with my Silverado pulled my hair out trying to find the cause, finally gave in and left it with the dealer, they found the source.....alternator was sending 800mv spikes to the bcm and making the bcm think the vehicle was being shut off & restarted in milliseconds..... a very rare case, I am in no way implying this is your problem I am just giving a example things like this can be very hard to find and it may be more time and cost effective to take it to a pro. yes it can be satisfying to find the cause but for sure something is shorted and finding the short can sometimes take a oscilloscope and the knowledge of what to look for in that data feed.
just my .02

 

[Mighty Hd]

Ok. Here’s the pattern that I am getting: I have tested each scenario for multiple driving cycles.

Factory tune:
Engine power reduced message has gone away.

Blackbear tune:
Cold start - no issues
Hot soak - drive to destination (5-10mi full warm up)

turn the engine off for at least 5-10+ minutes.

The next key or ignition cycle will produce the engine power is reduced error.

I can cycle the key 1 or 5000 times and the message continues to come up


Put the factory tune on and it goes away


I have reached out to Justin / Blackbear several tikes with no response other than a tuner will get back to me over the past three weeks.

I do have a new ECM coming this Friday

I do NOT want to keep the factory tune on as I have the AFM disabled on the Blackbear tune…

 

[Doubeleive]

@BlackBearPerf

 

[BlackBearPerf]

We have received your emails and are waiting for Justin to take a look. We got the first email on the 12th of Jan. The tune is not going to just change or you cant lose the tune unless you tune over it, something else is going on. Justin helps people figure out their stuff but has to do it in the order received.

UPDATE Justin just emailed you back.

 

[Mighty Hd]

Message sent back with all the details. I checked my outbox and apparently the first message that I composed at the end of December never sent and is hung in my outbox, I stand rightfully corrected. I did send the second message (first) on the 12th.

I’ll keep this thread updated. Still having the issue and I’m completely out of ideas. I have a new ECM in route just in case.

 

[Mighty Hd]

Still no real updates. I changed the coolant temp sensor and thought I fixed it as the problem didn’t surface for about a week.

It has been “cold” here in central florida…the one day it warmed up the problem came back.

BUT now I’m getting some new codes align with all the others. Vehicle runs fine…no hard DTC set. These codes come and go like the rest.

I was able to find a brand new ECM and have it in hand….looks like that may be next.

Just so happened the new Toyota Sequoia was released and damned if I’m not thinking hard about trading after this mess.

 

[Mighty Hd]

So some more driving and results:

There is no CEL or DTC being set.

Engine power is reduced / cylinder deactivation solenoid errors ONLY happens with the Blackbear tune installed and after the vehicle is fully warmed up, and a shutdown occurs (hot soak) of at least 30 min.

Factory ECM tune does not produce engine power is reduced message / cylinder deactivation solenoid errors.

New Ecm is pending dealer scheduling.

 

[Mighty Hd]

Installed the datalink LAN terminator resisotor today above the spare tire. #88988999 as suggested by another user. No change in behavior.

Engine Power is reduced message does not appear with the factory tune installed.

The instant that I put on the blackbear tune, and even before I start the vehicle (key to ON) the EPR message appears. No DTC codes set, MIL is not on.

I'm wondering since I changed the fuel pump / throttle body if the tune is somehow tied to those and is throwing the message up?

I have a few messages into Justin @ Blackbear. I'll update the post when he replies

 

[Doubeleive]

Installed the datalink LAN terminator resisotor today above the spare tire. #88988999 as suggested by another user. No change in behavior.

Engine Power is reduced message does not appear with the factory tune installed.

The instant that I put on the blackbear tune, and even before I start the vehicle (key to ON) the EPR message appears. No DTC codes set, MIL is not on.

I'm wondering since I changed the fuel pump / throttle body if the tune is somehow tied to those and is throwing the message up?

I have a few messages into Justin @ Blackbear. I'll update the post when he replies

maybe if the throttle body was different than the original, I have mine tuned with a ls7 throttle body I would maybe have a issue if I went back to stock throttle body with the same tune, if it did it would most likely it be something like air ratio incorrect, etc or if I changed the intake back to stock it would for sure, even a minor intake change with a tune can cause a code. I found that out with my Silverado I have a BB tune and I have a Cold air inductions intake and modified throttle body the CAI intake has a sleeve inside it's maybe a 1/4" thick by 4" long, when I took it out I got a code right away so I put it back in and code went away.