2016 Chevrolet 3500 LML

Hey guy's, Well I'm new to the forums, based in South Carolina I own a Diesel repair and performce shop. I have used many EFILive devices in the past and current. I am currently having a issue with a vehicle im my shop. I was hoping I could get some insite on this current issue.

I have a 2016 Chevrolet 3500 high country with 339k miles on it the owner has taken very well of this truck I have been working on it and servicing it for 3 years for him. A few months ago he dropped it off said it was running bad and skipping. I discovered it had a hole in the number 1 piston looked to be melted also. So we installed a Long block, whole new fuel system, BD Power diesel 64mm screamer, Banks welded charge air cooler with bigger pipes. (It was already tuned before it came to me.) Programmed the IQA codes, confirmed the IQA codes with GDS2 programmed them to GPCM and reset fuel learned values, went for a test drive and im feeling a shutter at 45-70 mph only when you load the engine in 5th gear. I get random injector balance and timing codes some times it may be 1,4,5 other times it will be 6,3,8,5 then again it will be 2,8,6,3 or 1,4 or 6,8 its random they are exceed learing limint injection timing and injection balance.

P02D9, P02D3, P02D7, P01D8, P01D2, P0263, P01D6, P0281, P0272, P0278

when TCC is in this happens see attached..

https://imgur.com/rzgZNTs
https://imgur.com/U5u6SA1
https://imgur.com/8Bcn3VK

The long block and fuel system came from jasper engines, I called tech support they are telling me that the TCC can cause the crank to feel that torque converter locking up and shuddering which in return could cause the injector codes. When I went back and test drove the truck I commanded the TCC off while the truck was shuddering and the shuddering went away. If i drive under 45-60 with no load I dont get the injector codes.

What I have done?

Retuned engine

Overlayed all injector circuits to each injector, changed IQA codes for giggles, changed MAP changed MAF, Truck has a air dog fuel pump has good flow and 10-12 psi supplied to the pump on the engine, timing it set CP4 pump gear dont between cam gear dots.

Can a locking or slipping converter cause random injector balance codes under a load in 5th gear between 45-70?? it's a new one to me

Any help would be grateful!!!

see if you can watch tcc slip speed command vs tcc slip speed actual. when it slips over 130-150 when being commanded 0 tcc slip thats probably when you start feeling the shudder. if you can command full tcc lockup while its shuddering and it goes away the tcc is just worn and glazed over. the trans fluid will also have a distinct scent.


also you need to make sure to perform the crank variation learn after engine replacement as well.

I know for sure it’s coming from the converter but could that really be causing the injector codes? That’s the big question I have about it.

hard to say really. although if the vehicle is trying to stay at a steady rpm and if fluctuates it may be hard for the ecm to inerpret the fact that its not fuel related. it may just assumed that its something else. but have you performed the crankshaft variation learn ?

Circuit/System Verification
1-Verify the proper fuel is used. Refer to Fuel System Specifications and Contaminants-in-Fuel Diagnosis.
2-Verify there are no aftermarket performance enhancing devices installed on the vehicle.
3-Perform the Fuel Injector Correction Reset for the appropriate fuel injector. Refer to Fuel Injector Correction Reset.
4-Perform the Crankshaft Position Reluctor Wheel Learn. Refer to Crankshaft Position Reluctor Wheel Learn.
5-Perform the Fuel Injector Timing Learn to verify that the DTC does not reset. Refer to Fuel Injector Timing Learn.

If DTC resets
Refer to Circuit/System Testing.

If DTC does not reset
All OK.

Circuit/System Testing
1-Perform a engine compression test. Refer to Engine Compression Test.
2-If engine compression is not within specification
Repair as necessary.

If engine compression is within specification
Replace the appropriate Q17 fuel injector.

Update changed torque converter shudder went away, codes still the same!!! Jasper sent 8 new injectors and still same issue, swapped ECM, changed Tune same issue, replaced wire harness same issue, Jasper sent a new engine I swapped the engine and same issue injector 1, 8 exceeded learning limits. Cam and crank sensor has been changed, S&S diesel CP3 swapped. Same result no change…… I’m at a lost !! Any ideas?

I am having the EXACT same issues that you're describing and have tried many of the same things to resolve it without success. I have checked everything I can possibly think of and am at a loss. Truck has the 2nd new motor, new injectors, balance rates are good, compression test was perfect, etc. Did you ever figure out what was causing the issue and get things resolved? If so, could you PLEASE share that info because I'm completely stumped on this one and don't even know where to look next :throw:. Thanks in advance for any info you can share.

The fix was return the ECM to stock, yea you will have light on the dash and messages but you will have X till reduced engine power

Return to stock
Clear codes
Go back and now program the IQA codes to the ECM copy to the GPCM
Confirm your IQA codes
Reset fuel min max values
Now go drive the truck perform the crank relearn
Once complete you can put the tune back in the ECM


If you have any issues don’t hesitate to direct message me and we can chat on the phone