Simple question, If your ecbm goes bad on a "99" Vette can you simply unplug the damn thing and drive it like we did in the old days when we didn't have all this stuff! Ive managed to drive a lot of cars over the last almost 50 years that were a heck of a lot quicker and never had a problem. Also, can a tuner turn off the service active handleing/traction control light? My ecbm is fine by the way but I've heard a lot of horror stories about these things gone bad and how the general no longer makes the units.

 

It's ebcm. If you'll do a search on the forum, there are several posts about the options you have to work with. Unfortunately, not too many with the 99.

 

My opinion FWIW, most of the "horror stories" are like you, worried about the possibilities. No actual data to support this but I have read many of the threads and most of the actual failures seem to be with the "repairable" 01-04 units.

I know there certainly have been failures of the early units. It's just that I hear more hysteria about not being servicable than posts about ones that are really bad.

If mine goes, I'll either look for a used one or put some black tape over the DIC. I live with a woman, I don't need a car telling me what's wrong.

 

Yeh, but woudn't it drive iradicallly if it was messed up? A friend of mines 2001 Vert started driving bad with the brakes coming on when he hit a bump in the road causing the car to pull hard to one side. He was fortunate enough to find a place that rebuilt these units but only 01 and up units. I' always turn the thing off about every time I drive it because I'm paranoid about it after his experiences. I thought just unplugging it would turn it off permanitly.

 

I had the same problem on my 99. Mine also has the Active handling which I believe is controlled from the same module. I tried jacking the rear wheels off the ground, started it up, put into drive, accelerated a little and let them spin up. I did this a few times and now all is well. no more DIC display or ABS light. Maybe I"m just a lucky one.

 

My 2000 EBCM has been out for a while and the only problem is having to clear the alert messages every time you start it up. As stated it drives like the old days,,if you stomp the brakes,,it will skid,,stomp the gas the the tires spin. I will eventually fix it, thought I saw a thread where someone is repairing the old ones,,but my old computer crashed and lost my bookmark!! I DO like the idea of ABS and such,,but I have driven for MANY decades without,,so I'm not that nervous in the interim.

 

But would it hurt anything to just unplug the darn wires from the ecbm so that there would be no danger of it kicking on at a bad time?
My friends Vert was so bad it would do weird things with the brakes while he was just driving along. he refused to drive it for about a month until I told him about a place that rebuilt them. Unfortunitly, they wont rebuild "97"-"99" ecbm's. Mine hasn't caused any problems yet but I think it's comming. Also, If i unplug the thing will it also shut off the stupid traction control?

 

that is why I love driving my C3 454. 450hp and 500 ft/lbs of torque will tear up a set of those 15 inch tires pretty fast. It definitely teaches you the meaning of the world gentle.

 

ebcm

 

You are correct ebcm.. Still the same question?

 

My 99 used to throw the service traction control message. I cleaned all the grounds and connectors under the hood and it seldom ever throws the code now. Usually only when it's cold outside

 

Mine has been on for 4 months or so. No issues. And then every once in a while it surprises me and works for a while, until it gets warm and I turn off the car. Then when I restart, it's right back on.

I wish the dang thing wasn't even on it. It's a pain the butt. (this is the only car I ever had that it was an issue) And it was an issue because GM changed it up in 01, so don't even try to tell me they didn't know it would cause future problems. No wonder they went broke.

 

They changed the entire system in 01 not just the module. From what I have read, it was an upgrade for the performance of the system and not due to any problems with the ebcm. And I'll say it again...I hear more of the 01-04 modules failing than the early ones. Yours being an obvious exception. So it isn't like they improved the ebcm in 01.

 

From what I've been reading on C5Wolfe's posts, his module hasn't failed. He said on another post that it was working, but he was afraid it would quit after reading that they couldn't be repaired.

 

I was refering to RetiredSFC post. He has stated before that his is broke. One of the few early ones reported here.... at least that I have read about here.

 

Yes, from everything Ive read you can unplug it and you will not hurt anything driving it that way. If you look at the system, the EBCM provides "additional" braking, meaning more than none (if you arent on the brake but it reads that you are out of line) or more than you are applying to slow which ever wheel is either spinning faster due to too much power or to which ever wheels slowing will improve your line. Without it, any pressure you put on the brake pedal still goes to the calipers.


Also, you sure your friends car had stock (or properly biased) sized rims/tires? Because screwing that up will also cause AH/TC to go postal.

Just thought of something else, although it wont "hurt" anything it will also effect the steering.
I stole this from a Bill Dearborn thread:

Find an auto parts store that has a scanner that can read ABS codes. There could be an issue with your MagnaSteer subsystem. All Corvettes since 97 have had Magnasteer which adjusts steering resistance based on car speed. Magnasteer is controlled by the EBCM (why the scanner needs to be able to read ABS codes) and the steering rack.

Here is a description of how Magnasteer works:
Variable Effort Steering System Description and Operation
The Variable Effort Steering (VES) system, or MAGNASTEER II® varies the amount of effort required to steer the vehicle as vehicle speed changes or lateral acceleration occurs. At low speeds, the system provides minimal steering effort for easy turning and parking maneuvers. At high speeds, the system provides firmer steering (road feel) and directional stability. When the system senses lateral acceleration, steering becomes firmer to reduce oversteering. The Electronic Brake Control Module (EBCM) controls a bi-directional magnetic rotary actuator located in the steering rack and pinion. The EBCM varies the steering assist by adjusting the current flow through the actuator. The actuator adjusts the amount of power steering assist to achieve a given level of effort to steer the vehicle. The VES system accomplishes this by adding or subtracting torque on the input shaft to the rack and pinion. The main component of the system is an electromagnetic actuator, which consists of a multiple-pole ring-style permanent magnet, a pole piece, and an electromagnetic coil assembly. The VES system uses the Antilock Brake System (ABS) wheel speed sensor inputs to determine vehicle speed. When the EBCM senses vehicle speed, it commands a current to the actuator that is most appropriate for each speed. The system also uses inputs such as Handwheel position, wheelbase, understeer coefficient and steering ratio to calculate lateral acceleration. The EBCM commands current from negative two amps to positive three amps to the actuator, which is polarized. At low speeds, a negative current is commanded, which assists steering. At medium speeds, no current is commanded and steering is assisted by hydraulics only. At high speeds, a positive current is commanded, which creates steering resistance. Ignition voltage and ground are provided through the EBCM. The EBCM has the ability to detect malfunctions in the actuator or the circuitry to the actuator. Any malfunctions detected will cause the system to ramp to zero amps and steering will be assisted by hydraulics only.

Here is the diagnostic for the one fault code related to this subsystem:

Diagnostic Instructions
DTC Descriptor
DTC C0450: Steering Assist Control Solenoid/Motor/Actuator Circuit
Circuit/System Description
The variable effort steering (VES) system uses the electronic brake control module (EBCM) to control current to a bi-directional electromagnetic rotary actuator. The EBCM commands current from negative 3 amps to positive 3 amps to the actuator. At low speeds, less than approximately 24 km/h (15 mph), negative three amps of current is commanded, providing maximum assist to steering. As speed increases, increased (more positive) current is commanded, reaching zero amps at approximately 96 km/h (60 mph). The EBCM commands positive current only during steering input at higher speeds, based on the above inputs and the vehicle calibration, which creates steering resistance.
Conditions for Running the DTC
•
Ignition voltage between 10.5-17 volts

•
Off state test--Initial ignition ON, no engine RPM or vehicle speed present.
•
On state test--If off state test passes, engine RPM and vehicle speed present.




Conditions for Setting the DTC
The EBCM detects an open, short to ground, or short to voltage in the VES actuator or the actuator circuits.
Action Taken When the DTC Sets
•
DTC C0450 is stored in memory.

•
The driver information center (DIC) displays the SERVICE STEERING SYSTEM warning message.
•
The VES system is disabled for the remainder of the ignition cycle.





Conditions for Clearing the DTC
•
The condition for setting the DTC is no longer present.
•
The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.



Diagnostic Aids
The vehicle may need to be driven to view full VES Actuator Commanded and Actuator Feedback Data parameters.
Circuit/System Testing
1. Ignition OFF, disconnect the VES actuator harness connector.
2. Measure for 0 volts between the variable effort steering actuator supply voltage circuit terminal A and ground.
⇒
If the voltage is greater than the specified range, test the variable effort steering actuator supply voltage circuit for short to voltage. If the circuit tests normal, replace the EBCM.
3. Ignition ON, measure for 12 volts between the variable effort steering actuator supply voltage circuit terminal A and ground.
⇒
If the voltage is less than the specified range, test the variable effort steering actuator supply voltage circuit for short to ground or open/high resistance. If the circuit tests normal, replace the EBCM.
4. Connect a test lamp between the variable effort steering actuator supply voltage circuit terminal A and the variable effort steering actuator control circuit terminal B at the VES actuator harness connector.
5. Using a scan tool, command the VES actuator ON. Verify the test lamp illuminates.
⇒
If the test lamp does not illuminate, test the variable effort steering actuator control circuit for open/high resistance. If the circuit tests normal, replace the EBCM.
6. If all circuits test normal, test or replace the VES actuator.
Component Testing
1. Ignition OFF, disconnect the VES actuator harness connector.
2. Measure for 5-10 ohms of resistance between the VES actuator terminals A and B.
⇒
If the resistance is outside the specified range, replace the VES actuator.
3. Measure for infinite ohms of resistance between each VES actuator terminal and the VES actuator housing.
⇒
If less than the specified range, replace the VES actuator.



This may not be the problem but it is easy to check yourself using a DVM.

Bill

http://forums.corvetteforum.com/c6-t...h-helpppp.html