Stabilirak Off, Traction Control Off, Engine Light On, Into limp Mode - In that order, while driving

[Joseph Garcia]

This has happened to me twice in a row (once on the highway, and once in city traffic), and I'm looking for suggestions regarding identifying root cause, or troubleshooting suggestions from the knowledgeable folks here on the Forum. Between the first and second failures, I replaced the batteries, so that potential cause has already been ruled out.

Here is the situation and trouble codes:

2007 yukon xl denali cruising down the road, when the Stabilitrak Off warning starts flashing. Shortly thereafter, the Traction Control Off warning starts flashing, also. Shortly thereafter, the engine warning light comes on, and the truck goes into limp mode. Scanner shows the following trouble codes (No existing trouble codes, prior to this occurrence.)


ECM 8 codes
U0140 - Lost communication with the BCM
U0121 - Lost communication with the ABS control module
U0101 - Lost communication with the TCM
P0700 - TCM requested MIL illumination
U0101 - Lost communication with TCM
U0140 - Lost communication with the BCM
U0100 - Lost communication with the ECM/PCM A
C0242 - PCM indicated TCS malfunction

EBCM 5 codes
U0140 - Lost communication with the BCM
U0121 - Lost communication with the ABS module
U0101 - Lost communication with the TCM
P0700 - TCM requested MIL illumination
U0101 - Lost communication with the TCM


ESC - Electronic Suspension Control Module 3 codes
U0140 - Lost communication with the BCM
U0121 - Lost communication with the ABS module
U0101 - Lost communication with the TCM


TCM 2 codes
U0140 - Lost communication with the BCM
U0121 - Lost communication with the ABS module


BCM 1 code
U0140 - Lost communication with the BCM


Rollover Sensor 1 code
U0140 - Lost communication with the BCM

 

[Fless]

Bump for visibility

 

[Marky Dissod]

I'm not an 'authority' on this, but whenever any of the vehicles in any of the taxi fleets I've ever worked with suffered several codes at once or in rapid succession,
EVERY grounding was removed, cleaned, lightly resurfaced, and reinstalled, and to clean each connector to every module that coded PRIOR to troubleshooting.
(Kinda like 'Tap-Rack'Bang' before 'SPORTS'.) More often than not, the codes did not reappear after the above steps were taken.

 

[rdezs]

I'd also check the resistance on the battery cables. They tend to fail from within, and that definitely looks like a connection issue somewhere

 

[Joseph Garcia]

Thank you for your replies. Much appreciated.

I checked the battery cables, and they are good from a resistance standpoint.

I am in the process of checking/cleaning grounds now. In fact, I'm on my way out into the garage now to continue that process, which I started yesterday.

 

[solli5pack]

That many codes at once makes me think a bad ground somewhere.

 

[Fless]

Do more than a resistance test on the cables and connections -- do a voltage drop test to verify that they can handle a high amp load.

 

[Joseph Garcia]

Do more than a resistance test on the cables and connections -- do a voltage drop test to verify that they can handle a high amp load.

Will do.

 

[PG01]

Definitely ground Joe. Its been raining a ton here in NY and I believe you’re getting it as well so i wouldn’t doubt your neg batt cable is fubar or a ground on the frame under the drivers door…

 

[PG01]

How’d you do Joe? Find anything?

 

[Joseph Garcia]

How’d you do Joe? Find anything?

I checked the ECM X2 connector and it looked clean and dry.

I cleaned and greased the ground #103 on the front of the motor's passenger side head. It did not look all that bad, but it was not clean.

I cleaned and greased the ground #300 on the frame under the driver's door. It did look very corroded, quite possibly corroded enough to impact current flow.

I found a possible chaffed wire in the cluster going into the rear of the transmission, which appeared to be rubbing against the edge of a heat shield on the side of the transmission. I taped the chafed wire and wireloomed and taped over the entire wire cluster and attached it away from the possible chafing spot.

I also cleaned and re-oiled my motor's intake air filter.

Today, I will run the voltage drop test on the positive and negative battery cables, as @Fless recommended.

Grok recommends checking and cleaning the ground #201, which is located up under the dash on the drivers side. This ground will be a challenge to get at, without some dash disassembly work, so I'm still on the fence regarding whether or not to tackle it.

 

[mikez71]

Grok recommends checking and cleaning the ground #201, which is located up under the dash on the drivers side. This ground will be a challenge to get at, without some dash disassembly work, so I'm still on the fence regarding whether or not to tackle it.

BCM ground huh? Just need to pull A-pillars and pry the defroster panel up.
BUT you risk breaking some retention tabs on the defroster panel, or the tab receptacles in the dash..
That ground isn't exposed to the elements, so personally I would skip it until you've tried everything else..

 

[mikez71]

BTW your list of codes reminds me of this guys...

2010 Tahoe LTZ electrical saga, need some input... - SOLVED

Our 2010 Tahoe LTZ has been an absolute beast since we bought it at roughly 125k; it's got 188k now and I've kept it in pretty solid condition the whole time in spite of heavy usage...and have avoided a lot of the typical problems with these things. Thing still easily books for 10k in my area...

www.tahoeyukonforum.com

Which ended up being a bad onstar module, but it seems like possibly any bad module can do it? idk..

If so, it might be worth taking a look at the suspension module, since it seems I've heard of bad connections there more than once..

 

[solli5pack]

Is there a way to look at freeze frame data to see what actually set the codes off? All those loss of communication codes means the CAN wen down?

 

[Fless]

BCM ground huh? Just need to pull A-pillars and pry the defroster panel up.
BUT you risk breaking some retention tabs on the defroster panel, or the tab receptacles in the dash..
That ground isn't exposed to the elements, so personally I would skip it until you've tried everything else..

I have seen some info on the driver's side ground under the dash cover, where it was manufactured with some plastic or other material under the ground lug. That prevented a good ground. Believe there was a TSB on it, but I'm not sure if it was for this MY.

 

[mikez71]

Is there a way to look at freeze frame data to see what actually set the codes off? All those loss of communication codes means the CAN wen down?

It *seems* like to me, when the network goes down, whatever modules were expecting a signal first may code first, which could have nothing to do with where the bad connection is..

 

[solli5pack]

Might be worth doing a resistance test on the can bus to make sure it's intact. I don't know the exact numbers right know but you do an ohms test from the DLC and check if it sees the resistors in the network. I believe it should be 60ohms but not 100% sure. It's a quick test that can at least verify the networks integrity.

 

[Fless]

Backing up a bit, have you tried removing the underhood fuseblock and reseating it? Maybe check connections underneath it?

 

[Joseph Garcia]

Backing up a bit, have you tried removing the underhood fuseblock and reseating it? Maybe check connections underneath it?

I have not.

 

[PG01]

I have not.

Forgot about that, good call steve