Well. I'm back. Second day that I drove to work last week, the ABS,Traction Control,Brake ans Service ESC lit up. No shifting issues. Ran fine up until 7/23/19 and then lit up again 5 miles from home with trans shifting hard and speedo bouncing. Also, ambient air temp going out. Got the Autel scanner from my co-worker to review history. Main items: C0550-37 ECU performance and C0292-39 Combination Sensor Circuit. Bias Level Out of Range. Checked operation while driving and all wheel sensors are in sync.I will check for grounds again this evening, but to me, all things point to EBCM going out. No more loss communications with the PCM and TCM though, at least that is good (so far?)
Also, if I replace the EBCM with a new one, does it have to be programmed?

 

First check your Yaw sensor since that is the sensor in question (C0292). Has the car ever deployed airbags?

 

Vehicle has never been in an accident or had the airbags deployed. Looks like the sensor is under the center console. I believe the Autel scanner I was using can check the sensor in Live mode. I will have to check it out this weekend. But, at least I have some direction to go in. Does the EBCM module have to be programmed if replaced? Also, when these warnings came up, the transmission was hard shifting. From what I have read, this code causes the 12 volt reference to drop out until vehicle is restarted.

 

The EBCM provides the 12V ref.

The #1s in the drawing are the nuts that hold it down to the floor.

I think the EBCM does need to be programmed.

 

lake runner , i have a 08 lt with abs and i have been dealing with the same prob i have done every thing as others have listed and had no luck even change the trans , we finaily pulled the one year only abs brain and changed it with a 011 and all my probs went away other then my 08 not liking the new brain as its not flashed to it and flash, we found i have to get the same part number brain for a 08 but have now driving it for 8 months with no repeat probs of the dash fricking out i just live with the abs light and trac light on for now , maybe worth a try good luck ,

 

I was checking for loose or corroded ground connections and found that I did not securely seat and latch the lower ECM connection. I seated and latched w/ locking pin and checked the OBD2 history log.
the most recent was C0550-37 ECU performance. With the history cleared, I have been driving around the past 2 days to see if anything pops up. So far so good, but I will be commuting with it starting Monday.

 

Good , thanks for the follow up , it will help a future reader.

 

{sarcasm alert}
Must replace computer. Computer bad. Computer evil. Couldn't possibly be a connection. Replacing computer fixed it, could not have been connections.
{end sarcasm}

I can't believe I heard it again elsewhere: "I've been an ASE mechanic for 20 years, I cant work on these modern cars because the computers are so confusing".

Let's see 1996-2019; that's more than 20 years. OBD2 was mandated in 1996 so all cars since have been computerized. Conclusion: ASE doesn't mean squat. Thankfully computers can be R&Rd with a wrench, no need to think, it ain't my money.

 

Don
You're starting to use sarcasm.

 

funny db lol not ,,,,, we put the old brain in and wala probs all come back change it and wala they go away so its not all ways what u think , pick on some one else i,m not your fun o ya just sarcasm dave ban me again cuz i stand up to your hate full posts