2000 ABS/EBCM problem
 

Hi guys.
I bought a C-5 Corvette back in 2000. I have kept it covered and in the garage most of the time. And well maintained. It now has 6,400 miles. After firing it up and driving a bit this summer it read a 1571 code (ASR Desired Torque). I have looked into this in detail and it seems to be a problem with the EBCM/ABS unit. I have inquired with GM and the part has been discontinued. The car is only 10yrs old. Has anyone out there experienced the same problem. I don't think it will pass smog this way. I have checked with ABS fixer etc, and they don't have an answer. Has anyone experienced this. I am not sure where to go from here. There seems to be a big problem with the 2000 Corvette with this issue. Any suggestions.

Gordon

It won't have any affect on the car passing smog. Have you tried clearing the code and seeing if it comes back? Is it just the ECBM or the hydraulic part of the ABS. I'm sure the ECBM is still available, but the'yre not cheap, $1200.

How do you know the EBCM is bad? Did you already troubleshoot per the service manual procedure for a P1571?

2000 EBCM problems.
 

I had my mechanic at West Coast Corvette diagnose the problem. He is sure it is the ECBM. Chevrolet has discontinued the part. I am having no luck in finding a replacement. I am going to take it to the dealer but I don't think there is much they can do. Apparently for the yr 2000 you cannot get the EBCM any more. Before or after are still available. I am wondering if anyone had the same problem and how they resolved it. It has never been driven in the rain and is stored in a CA garage for the past 10 yrs so I am sure it is not a corroded ground issue. Only 6400 miles. Very frustrating. Thinking of trading it in at the dealer but that may not fly. Right now it is a showroom condition parts car. Thanks for your help.
Gordon

I think one problem does not make this a parts car......:lol:

Without knowing exactly how the system was evaluated, I would not be convinced that the EBCM is bad. Sorry, but I've corrected many problems for other people, that so called C5 experts misdiagnosed.....or simply could not figure out. Given the availability and cost of the part, I think a second opinion is in order........

Thanks. I will do just that.
Gordon

I have the same issue with the same car (23k miles). Two years ago I located a salvage part ECBM and it lasted until now. ABS Fixer could not repair it because he only does 2001-2004. He claims the 2000 are not rebuildable.
I took the part out and the car works fine but w/o the safety features.
I am looking at Auto computer systems for a warranteed rebuild for 359. Their # is
1 877 870-8148

EBCM repair
 

Hello, did you ever find anyone to repair your EBCM on your 2000?? Thanks

2000 ECBM Problem
 

I found a site called BBA Reman (1866 573-2740) that will "try" to repair it. I was told that when I get it back I have to reinstall and test it on the car. They will give a refund if its a failure. .

The problem with the pre-2001 units is that when you start the car, it self checks all of its systems. The voltage spike that tests the ABS pump tends to burn out the ECBM. It is also more difficult to repair the printed circuits on these units. The 2001-2004 can be repaired and the "ABS Fixer" guy puts in a surge protector for an extra $50.

thank you, I will give them a call.

FYI 2000 EBCM Source
 

they say they can rebuild 2000 year Corvette EBCMs (ABS controller), Rebuild cost is $495.00,
Included is a 2 Year Warranty
To ship... 1st visit their website www.autoecu.com, click the forms tab, then click the R&R form, complete all the needed information, Package your part well and ship to address on the form. If you would like to contact.. their toll free for U.S. & Canada is 1-866-983-6688
If you need removal Instructions or Technical information email: tech@autoecu.com

Heres the write up for the DTC. Its a ONE wire signal from the EBTCM.

Give me an E mail address and I will send you the schematic and entire DTC protocal. Cant attach it all to the forum as it wont copy the picture when I copy it.

Circuit Description
The PCM supplies 5 volts on the desired torque circuit to the electronic brake and traction control module (EBTCM). The EBTCM toggles this 5 volt signal to a ground in order to produce a duty cycle signal. The signal is proportional to the amount of engine output torque reduction requested by the EBTCM. The EBTCM supplies this signal when it detects a wheel slip. In order to reduce engine output torque, the PCM reduces the amount of spark advance and in some cases, the PCM disables a number of fuel injectors. This diagnostic tests for a Desired Torque signal failure. If the PCM does not receive the Desired torque signal, this DTC sets.

Conditions for Running the DTC
The traction control has not failed.
The engine speed is greater than 500 RPM for 20 seconds.
Conditions for Setting the DTC
The desired torque signal is not received by the PCM for 3 seconds.

Action Taken When the DTC Sets
The powertrain control module (PCM) stores the DTC information into memory when the diagnostic runs and fails.
The malfunction indicator lamp (MIL) will not illuminate.
The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.
Conditions for Clearing the MIL/DTC
A last test failed, or the current DTC, clears when the diagnostic runs and does not fail.
A history DTC clears after 40 consecutive warm-up cycles, if failures are not reported by this or any other emission related diagnostic.
Use a scan tool in order to clear the MIL/DTC.
Diagnostic Aids

Important
Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the module. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM.
For any test that requires probing the PCM or a component harness connector, use the Connector Test Adapter Kit J 35616-A . Using this kit prevents damage to the harness/component terminals. Refer to Using Connector Test Adapters in Wiring Systems.
Do not perform this diagnostic procedure if the customer's concern is not related to the ABS and/or the Traction Control systems.

For an intermittent condition, refer to Symptoms .

Test Description
The numbers below refer to the step numbers on the diagnostic table.

This step determines if the EBTCM is receiving the 5 volts from the PCM. Use the connector test kit adaptor J 35616-A when probing the EBTCM connector.

If no DTCs are set, inspect connections at the EBTCM.

DTC P1571 Desired Torque Circuit Step
Action
Values
Yes
No

1
Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?
--
Go to Step 2
Go to Powertrain On Board Diagnostic (OBD) System Check

2

Important
Perform this diagnostic procedure only if the customer's concern is related to the ABS and/or the Traction Control systems. Refer to Diagnostic System Check - ABS in Antilock Brakes System.


Install the scan tool.
Turn OFF the ignition.
Disconnect the EBTCM electrical connector. Refer to Electronic Brake Control Module (EBCM) Replacement in Antilock Brakes.
Turn ON the ignition with the engine OFF.
Probe the Desired Torque circuit at the EBTCM electrical connector with the DMM connected to ground.
Does the DMM display near the specified value?
5V
Go to Step 3
Go to Step 4

3

Important
Verify communication between the scan tool and the EBTCM before you continue with this diagnostic. Refer to Diagnostic System Check - ABS in Antilock Brakes System.


Are any ABS/TCS/BCM DTCs set?
--
Go to Diagnostic System Check - Body Control System in Body Control Systems or Diagnostic System Check - ABS in Antilock Brake System
Go to Diagnostic Aids

4
Probe the Desired Torque circuit at the EBTCM electrical connector with the DMM connected to ground. Refer to Probing Electrical Connectors in Wiring Systems.

Does the DMM display near the specified value?
B+
Go to Step 7
Go to Step 5

5
Probe the Desired Torque circuit at the EBTCM electrical connector with a test lamp connected to B+.

Is the test lamp illuminated?
--
Go to Step 8
Go to Step 6

6
Test the Desired Torque circuit for an open. Refer to Testing for Continuity in Wiring Systems.
If you find an open circuit, repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 11
Go to Step 9

7
Repair the short to B+ on the Desired Torque circuit. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?
--
Go to Step 11
--

8
Repair the short to ground on the Desired Torque circuit. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?
--
Go to Step 11
--

9
Inspect for poor connections at the PCM. Refer to Testing for Intermittent and Poor Connections in Wiring Systems.
If you find a poor connection, repair the terminal as necessary. Refer to Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 11
Go to Step 10

10

Important
Program the replacement PCM.


Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement .

Is the action complete?
--
Go to Step 11
--

11
Select the Diagnostic Trouble Code (DTC) option and the Clear DTC option with the scan tool.
Start the engine and idle at the normal operating temperature.
Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number with the scan tool.
Operate vehicle within the Conditions for Running this DTC as specified in the supporting text, if applicable.
Does the scan tool indicate that this test failed?
--
Go to Step 2
Go to Step 12

12
Select the Capture Info option and the Review Info option with the scan tool.

Does the scan tool display any DTCs that you have not diagnosed?
--
Go to applicable DTC
System OK



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Document ID# 610939
2000 Chevrolet/Geo Corvette

2000 ECBM nightmare
 

But they are the only rebuilders who can warrantee for five years. Most give 30 days. They also said that they reverse engineer the rebuild to eliminate the original design flaw.
I will let you know what happens when it comes back.

GordonR and others, please keep the Forum updated on your progress. Good luck.

OT - I went w/ATE for my 2001 rebuild as they seem to be the most thorough in terms of testing - they test before they send it back to you and have a long warranty. And only $50 for the 2001-2004 rebuild.
I haven't received the unit (actually sending in 2) back yet, so will have results later.

How does this help? the 01' units are different. Most of the outfits that do this do 01-04 and nothing earlier.

OT = off the specific topic
But it is on the topic of choosing from which place to buy the replacement

How do they know there was an original design flaw? Just because something failed doesn't mean there is a design flaw. I wonder how they reverse engineer a module that has components with manufacturer specific part numbers on them with no data on what those components do or what is inside the components.

Bill

wild guess, they could use components (relays, switches, caps, resistors) rated to higher current values or higher quality components if those are failing.