Hello guys, if you guys don't mind helping me with my embc/swps codes and diagnosis. I would be forever grateful. My car has been in the shop for over a year. A ls2 was just installed in my 2004 C5. I think all the kinks have been worked out except some issues with my embc. I'm currently in the sandbox (Afghanistan), so I physically cant do anything myself. I'm trying to help the shop guys figure out the issue without spending a lot of labor time on it. So, they pulled the engine from the bottom, the entire drive train came out. While the engine was out, I sent my Embc out to have it fixed(forgot the company name). Because of some codes I was receiving, and lights on the dash. (cant remember the codes) Also, I brought a spare from a forum member that came from a 2004 as well. After, the engine installation. They installed the rebuilt module(original to car). And the received "no comm", after the install. Then , they put in the used unit. With the same code, "no comm". Then they found a broken wire, repaired that ground wire going to the embc, cleared the codes. then they started getting these codes:

c1248- embc turned on red brake warning lamp
c1254- abnormal shut down detected
c1281- vses sensor uncorrelated
c1284- lateral accelometer sensor bias malfunction
c1285- lateral accerometer sensor circuit malfunction
c1287- steering sensor rate malfunction
c1288- steering sensor circuit malfunction
sdm & ipc have u1040 code- no comm with the ebcm

I started doing research on these systems, and found alil on how they work. It seems to me as they are tied together. They then removed the used module(forum member), and reinstalled the original(rebuilt unit) and they still have the exact same codes. They rebleed the system. no help. same codes.

My questions:
1. Do the steering wheel shaft needed to be disconnected to drop the drive train from the bottom? I'm asking this, because I read if its disconnected, and the steering wheel is moved while its disconnected, it can cause a lot of issues.

2. Should I just buy a dealer Ebmc, and a swps? Really don't like throwing parts at it. But will know these 2 components are 100% ok.

3. Can the hydraulic side of the ebmc, cause these promblems?

4. Do I have another wire issue somewhere?

Again, I'm in the sandbox, and cant do it myself. I will make recommendations to the guys whom are working on my car. They don't have a lot of experience with this system. Thanks for reading, and any and all help is greatly appreciated.

 

First things first. What is the battery condition and battery voltage read DIRECTLY on the battery terminals?

Check ALL the fuses to the EBTCM There are MULTIPLE fuses. Test the actual VOLTAGE on top of the fuses (two test slots on the fuse) to chassis ground. MAKE SURE that they are receiving full battery voltage at each fuse!!

The ground for the unit is at G-101 directly aft of the drivers head light & at the ground lug on the frame near the battery G-108.

Make SURE that the EBTCM connector is properly connected and the lock bail on the connector is fully shut.

Measure power AND Ground directly on the EBTCM Connector with a meter:

Here is a schematic for you:





Thank You for serving brother!

Bill

 

Thanks Bill, for chiming in. I will pass this info on to the mechs. Your welcome.

 

Here is the latest updates and codes. I'm going to post all the codes, even tho I'm just really concerned about the ebtcm codes. I'm posting the other codes, just in case something sticks out. my mechanic, resecured some wires at the ebtcm harness, and a lot of codes went away. the two codes he has now are c1248 and c1254. he said the repair manual is not clear on the explaination of these codes. and yes, there is fluid in the master cylinder. my objective with this is to turn those dash lights out.

my other codes if you think they are related:

p0103- from tuning
u1040
abs- c1248, c1254
bcm- 2648
hvac-b0363, b0441
u1096

thanks again all.

 

That C1248 code could mean big money.
The dynamic rear proportioning (DRP) is a control system that replaces the hydraulic proportioning function of the mechanical proportioning valve in the base brake system. The DRP control system is part of the operating software in the EBCM. The DRP uses active control with the existing ABS in order to regulate the vehicle's rear brake pressure.

C1254 DTC is set when the microprocessor compares a periodic checksum to a running checksum and finds they do not match. The checksums are areas of the computer's memory that hold critical operational data. Possible causes include: loss of battery ground, disconnected battery, computer malfunctions, sudden drop in system voltage below 5 volts, long extended engine cranks that cause battery voltage to drop, poor power or ground connections.


Looks like you may need a Tech2 to run a system check. If all the wiring checks out, and the test says it fails, looks like your gona be replacing the EBCM

 

thanks zz06 for the info. check my first post. I'm currently using a rebuilt ebmc, and the used one I got from a forum member, I may have to swap that one back in, to check to see if it still giving off the same codes.

 

Oh I'm sorry I missed that you had 2 modules. That would be my next move for a quick find.

 

thanks zz06. I just found a post that I responded to, he had 3 of my codes, and cleared them by cleaning the ignition switch contacts, I'm about to look up some info on cleaning those contacts on the ignition switch.

 

New update. Absfxer says the code 1254 is not fixable. It probably burned internal component during a jumpstart. I have a used one on hand that I got from a forum member. The shop will install next week. Crossing my fingers, hope it will work. If not have my eye on a new one from gm warehouse. Will update when they install the previously owned one.

 

GOOD NEWS! Keep us posted and hurry home!

 

Not to beat a dead horse but what are people doing right now when their EBCM is faulty on a pre-2001 car ? And how would it effect driving the car if it is broken ?
Also, after reading up on this point, I will never jump start my 2000 with a battery pack or cables, it stays on a tender 24/7 365 days/year..

 

They are finding used ones, from what I've read and heard.

 

Latest update. We swapped in the module I got from a member, still the same codes. The mechanic shop hired a new mechanic. Hes bee working it this week. He found a cut ground wire for the memory, repaired it. Traction control works as it should now. This is been a problem for 1.5 years. Im happy. Just need to get hime ri drive it now.