Need diagnostics for a friend

[Pepperidge]

I told him to come join here, and ask himself, but he just got out of the hospital...I'm just relaying what he's said so far...

I already suggested the fuel filter, he said it was just changed last month...

here are some of his descriptions...

My 2008 Duramax is finally giving me some trouble I can't fix, especially in my current state of affairs with this feeding tube in my nose and such.

My programmer isn't throwing any codes but it is running like shite. Like won't go over 30 mph. I've tinkered with the programmer and done Internet research and such but I'm not having any luck.


It ran like a champ up until I took it in for a water pump 3 weeks ago.

My main mechanic won't work on stuff with aftermarket stuff on it.

My main issue right now is that my main mechanic did some work on it last week with the aftermarket stuff in there, as he has in the past. What he did and what I have on there shouldn't have coincided with each other. Well now that I get it back, it's in limp mode and not wanting to run right. I've used him for years an not saying he did anything wrong but I'm kinda stuck and it couldn't have happened at a worse time.

I have an Edge CTS tuner, DPF delete straight pipe, and a BANKs RAM air.

I had a water pump put in. This was all done while I was in the hospital. When they got the water pump on, they said it wouldn't run right and said it was probably due to the aftermarket stuff. I agreed and said I would handle it once I got out of the hospital. I figured it was something minor like putting it back to stock and retuning it. No problem. Well that wasn't the case. I've tinkered with it all day today and can't figure it out. The screen in the truck, nor the programmer are showing any trouble codes.

ETA: I've had all that shite on there since about 30k miles and it now has almost 150k with no problems whatsoever to date.

Won't go. It's like it is running in limp mode.

It showed Reduced Engine Power code the day I picked it up from the shop and limped home with it from the shop so I could mess with the tuner at my leisure. It still won't go, but I can't get it to do that code again.

Runs perfectly fine at idle. Usually when something's wrong with it, it won't remote start. It remote starts fine and idles fine.

From what I gather, the water pump installation is a pretty involved repair but I don't know what they could have removed that would make it not run right afterwards and not throw any codes.

 

[THEFERMANATOR]

If it says reduced engine power then there should be a code. EDGE's are notorious for not reading out but select codes, so it would be best to read them with EFILIVE or a TECH2. Also tell him to look and see if it has a plastic fuel filter on it. They are KNOWN to be a POS and leak air in out of nowhere. ONLY use RACOR/AC DELCO fuel filters.

 

[Pepperidge]

Thanks Ferman...I'll pass this on...

 

[btfarm]

Could be they hooked up a Tech2 and messed up the EDGE tuning so there isn't proper communication. Like Ferman though, I'd get it read with a T2 and find out what is REALLY wromg.

 

[Pepperidge]

he just told me he's going to take it to some diesel performance shop in Baton Rouge...he's 80+ miles from me and he just got out the hospital and really doesn't wanna deal with it...I told him I'd be up there for an LSU baseball game on Tuesday, but he doesn't want to wait...I don't see why...he's pretty much off of work/stuck at home for now...

 

[WarWagon]

The LMM will limp if the air filter is missing. The Banks filter may have caught up with him. Check it's condition.

Clean the MAF esp as the oiled air filter can oil foul the MAF.

X2 on Wix plastic fuel filters. :shiiiiiite:

Water pumps are involved repairs as this one is gear driven. Check wiring and sensors in the area.

Check the driver's side boost tube for contacting a nearby wiring harness and melting/rubbing through.

You have to clear the code to get out of limp.

 

[Pepperidge]

Here's the latest...

I passed on WarWagons reply, which led to this one...

I clean my Banks filter pretty regularly, but it is almost 5 years old. There is also a "shuddering" type sound from the muffler area towards the front when I try to accelerate.


I could order a new banks filter if that turns out to be the problem,

I told him to clean the filter and the MAF

asked him about what level tune he's been running fearing the shudder may be the tranny

I don't drive the truck hard. I get in it every now and again, but that is rare.

When I first limped home with it fr the shop, it did flash the transmission signal on the dash once but it went away. I've cranked it several times since them trying to get it to show again. I can't even get it to show the engine underpowered message again.

I cranked I again today and it smelled more diesel fumes under the hood than usual and as I've already mentioned, it has a funny drone coming from the pipe up there. I'm at a loss.

could the trans flashing he's referring to be the shift indicator flashing referring to the NSBU switch?

 

[btfarm]

Internal NSBUs are pretty reliable. Not like the old external ones.

 

[Pepperidge]

Instead of paying for a tow...he wants to know how far/long can he drive it in limp mode...it about 20 miles to the diesel perf. shop he plans on taking it to...

truck idles fine...then has a shudder on accelleration and then goes into limp mode...

 

[Pepperidge]

Would this TSB for 2009's possibly affect his 2008?

2009 Chevrolet Silverado - 4WD | Sierra, Silverado VIN C/K Service Manual | Document ID: 2743912
#PI0310B: Loss of Communication with Allison TCM, Intermittent Transmission Hesitation, Reduced Torque, Range Inhibit, Clunk, Stuck in Gear or Neutral, Wont Shift, DTC P0880 and/or U0101 Set - (Dec 2, 2011)

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Subject:Loss of Communication with Allison Transmission Control Module (TCM), Intermittent Transmission Hesitation, Reduced Torque, Range Inhibit, Clunk, Stuck in Gear or in Neutral, Won't Shift, DTC P0880 and/or U0101 Set (Inspect for Electrostatic Discharge (ESD) From Aftermarket Serpentine Belts and/or Added Equipment, Install OEM Belt, Relocate TCM)

Models:2007-2012 Chevrolet Silverado
2007-2012 GMC Sierra
Equipped with Allison® A1000 Automatic Transmission RPO MW7

Attention:Please review the latest version of Corporate Bulletin Number 04-06-04-054B: Info - Non-GM Parts and Accessories (Aftermarket), for information regarding GM's policy on the use and installation of aftermarket components.​

This PI is being revised to add G102 information to the Condition/Concern and Recommendation/Instructions. Please discard PI0310A. The following information may be helpful if the vehicle exhibits the symptoms described in this PI.
Condition/Concern


Some customers may comment that the transmission will intermittently hesitate, clunk, gets stuck in gear or in neutral, won't shift, or experience reduced torque or range inhibit.
The technician may observe on a scan tool DTC P0880 and/or DTC U0101 set as Current or in History.
This condition may be caused by:

• Resistance in the G102 ground connection on the side of the engine block.
• During normal servicing, the OEM General Motors serpentine belt was replaced by an aftermarket serpentine belt.
• An aftermarket serpentine belt was intentionally installed, due to dimension changes from added aftermarket equipment such as a second alternator or clutch pump installed by an upfitter.​

Certain brands of replacement aftermarket serpentine belts are made of compounds that will reduce the opportunity for audible belt noise, however these compounds can generate significant amounts of electrostatic charge on their surface. This electrostatic charge can discharge and cause DTC P0880 and/or DTC U0101 to set and be accompanied by any of the above symptoms.
Recommendation/Instructions


Important: DO NOT replace the transmission control module (TCM) until the root cause of the problem has been properly resolved. The TCM ONLY NEEDS to be replaced if it has incurred permanent damage, such as hard failed codes, complete loss of communication or other erratic behavior that continues to exist AFTER completing the following steps.

1. Perform the Diagnostic System Check - Vehicle.
⇒If DTC P0880 and/or U0101 are set as Current or in History, and/or the above symptoms are observed, proceed to Step 2.
⇒If DTC P0880 and/or U0101 are not set as Current or in History, and/or the above symptoms are not observed, refer to > Transmission > Automatic Transmission - Allison > Diagnostic Information and Procedures in SI.
2. Turn OFF the ignition.
3. Disconnect and inspect the G102 wire terminal and connection for looseness and corrosion. Clean any corrosion from the wire terminal and the surface of the engine block with a wire brush.
4. Apply dielectric grease to the wire terminal and engine block surface. Connect the G102 wire terminal and secure properly.
5. Inspect the engine for an aftermarket serpentine belt due to service replacement or added aftermarket equipment from an upfitter.
⇒If an aftermarket serpentine belt is installed on the original serpentine system, without added aftermarket equipment installed on the engine, replace the serpentine belt with an OEM General Motors serpentine belt. Refer to Drive Belt Replacement in SI.
⇒If an aftermarket serpentine belt is installed because of added aftermarket equipment installed on the engine, proceed to Step 6.​

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Important: DO NOT relocate the transmission control module (TCM) if aftermarket equipment HAS NOT been installed on the engine.Relocate the TCM ONLY if an additional or longer accessory drive belt has been installed on the engine, resulting in the drive belt being closer to the TCM. Relocating the TCM on a vehicle that has not been modified, WILL NOT correct the DTCs and may result in a comeback.
6. Relocate the TCM (1) to the top of the UBEC cover and secure it using a heavy duty adhesive or Velcro® “hook and loop fastener”. DO NOT use push pins as fasteners, they will compromise the water resistance of the UBEC cover.​

Velcro® is a registered trademark of Velcro Industries B.V.
Allison® is a registered trademark of Allison Transmission, Inc.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

 

[WarWagon]

:hihi: Yes...

Again a code reader will tell us. Likely they put on a new belt as it has to come off to get to the water pump.

Models:2007-2012 Chevrolet Silverado
2007-2012 GMC Sierra
Equipped with Allison® A1000 Automatic Transmission RPO MW7


Damn strange TSB...

 

[btfarm]

Damn strange TSB...

No shit! Wierd as hell...

 

[Pepperidge]

Well it turns out that the mechanic who did the water pump left the passenger side intercooler boot off...

 

[btfarm]

Glad it was something simple... It usually is. WTH is with the mechanic not going out of his way to make it right-giving him the runaround.

 

[Pepperidge]

yep...IMO the first mechanic should have never let him leave with the truck like that...IIRC he blamed it on aftermarket things...

Here's the email from the shop that fixed it...

Fix was easy once we found it. Previous shop had left the passenger side intercooler off when reassembling truck. All the black smoke was due to getting zero boost into the intake manifold. We put it back on, cleared codes, verified tuning, and the truck is running good.

---

Now one thing though... the guy never told me it was smoking black badly...just not running right and the "shudder" I think that would have helped us get it diagnosed to have him check a couple of things...

but then again...there wasn't much he could do with just having surgery and being at home with a feeding tube in his nose...I would guess thats why he gave up so quick and took it to a shop...when you are feeling that bad, you really don't want to deal with that sort of thing...

 

[THEFERMANATOR]

How in the heck does one leave the boot off. It's a friggin quick connect that pops on and off for crying out loud.