EBTCM No Comm.
Instructor
Joined: May 2008
Posts: 218
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From: LA from the 6th sept till the 10th sept california ( then New Zealand)
hey bill , you say to try this....
"3. Disconnect STAR 1 and STAR 2 connectors and read each module serial data terminal to chassis ground. If one of the readings is out to lunch, that module is likely the issue."
can you tell me what readings i should expect to get to chassis ground?
should they all be the same?
am i testing resistance? or continuity? my OHM readings dont seem to register on my meter.
help...
"3. Disconnect STAR 1 and STAR 2 connectors and read each module serial data terminal to chassis ground. If one of the readings is out to lunch, that module is likely the issue."
can you tell me what readings i should expect to get to chassis ground?
should they all be the same?
am i testing resistance? or continuity? my OHM readings dont seem to register on my meter.
help...
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Your voltage/s look OK but still dropped down on the ignition circuit. The module cut off voltage is close to 9 VDC but,, just because the voltage is good today, doesn't mean it will not be bad on the next ignition cycle.
When you get the module back, install it and do the measurements again.
BC
When you get the module back, install it and do the measurements again.
BC
Instructor
Joined: May 2008
Posts: 218
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From: LA from the 6th sept till the 10th sept california ( then New Zealand)
thanks , yes got module back today. plugged it in and No joy.
bill can you clarify my last post re star 1 and 2 ?
also what do you think of my PCM and BCM codes that i posted earlier on in this thread? could this be the problem?
i will test voltage again with the module installed.
bill can you clarify my last post re star 1 and 2 ?
also what do you think of my PCM and BCM codes that i posted earlier on in this thread? could this be the problem?
i will test voltage again with the module installed.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Well,, 11.92 VDC isnt the end of the world. Should be enough to make the module happy. If you want it closer to true battery voltage,,, you will have to repair or replace your ignition switch. I really dont think that will resolve the issue but, you could run a wire directly from the battery POS terminal to the ignition supplied contact and see..
Bill
Bill
Instructor
Joined: May 2008
Posts: 218
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From: LA from the 6th sept till the 10th sept california ( then New Zealand)
OK bill tried that and still no luck..... i hope the speedoguy was 100% honest with me and it did not have a fault....
Does the EBTCM rely on the PCM to come to life or??? or can it have basic function without communication with it? i do have those pcm codes .....
any other ideas??
Does the EBTCM rely on the PCM to come to life or??? or can it have basic function without communication with it? i do have those pcm codes .....
any other ideas??
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Unless those guys have rigged up some sort of fancy test gear,,, I DO NOT see any way for them to test anything.
IMHO, all that they do is inspect the boards solder joints, resolder any that look bad, repair any circuit board traces that look bad and replace the power relay.
The ABS guy says that he adds a special power surge suppressor but, I have never seen it in person.
NONE of them (NONE) can repair any thing but a power related DTC issue. If they have spare modules, they can replace broken hard parts that are soldered to the board.
If the microprocessor has an issue,,,,, Stick a fork in it,, ITS DONE!!
I'm not sure of your meter reading skills and the ability to properly probe for the correct info. If it were me,,,,,,,,,,,,,,,,,,,,, I would disassemble the main EBTCM connector, look for damaged wires, examine EACH pin and insert a male pin in each female pin and insure that each female pin wasn't spread and make positive that all my basic module power and grounds were 100%.
Once you do that,, it has to be the module. You can get a O scope and read the output of the module and see if theres a digital signal there but thats reaching deeeeep.
BC
IMHO, all that they do is inspect the boards solder joints, resolder any that look bad, repair any circuit board traces that look bad and replace the power relay.
The ABS guy says that he adds a special power surge suppressor but, I have never seen it in person.
NONE of them (NONE) can repair any thing but a power related DTC issue. If they have spare modules, they can replace broken hard parts that are soldered to the board.
If the microprocessor has an issue,,,,, Stick a fork in it,, ITS DONE!!
I'm not sure of your meter reading skills and the ability to properly probe for the correct info. If it were me,,,,,,,,,,,,,,,,,,,,, I would disassemble the main EBTCM connector, look for damaged wires, examine EACH pin and insert a male pin in each female pin and insure that each female pin wasn't spread and make positive that all my basic module power and grounds were 100%.
Once you do that,, it has to be the module. You can get a O scope and read the output of the module and see if theres a digital signal there but thats reaching deeeeep.
BC
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Instructor
Joined: May 2008
Posts: 218
Likes: 0
From: LA from the 6th sept till the 10th sept california ( then New Zealand)
Instructor
Joined: May 2008
Posts: 218
Likes: 0
From: LA from the 6th sept till the 10th sept california ( then New Zealand)
Unless those guys have rigged up some sort of fancy test gear,,, I DO NOT see any way for them to test anything.
IMHO, all that they do is inspect the boards solder joints, resolder any that look bad, repair any circuit board traces that look bad and replace the power relay.
The ABS guy says that he adds a special power surge suppressor but, I have never seen it in person.
NONE of them (NONE) can repair any thing but a power related DTC issue. If they have spare modules, they can replace broken hard parts that are soldered to the board.
If the microprocessor has an issue,,,,, Stick a fork in it,, ITS DONE!!
I'm not sure of your meter reading skills and the ability to properly probe for the correct info. If it were me,,,,,,,,,,,,,,,,,,,,, I would disassemble the main EBTCM connector, look for damaged wires, examine EACH pin and insert a male pin in each female pin and insure that each female pin wasn't spread and make positive that all my basic module power and grounds were 100%.
Once you do that,, it has to be the module. You can get a O scope and read the output of the module and see if theres a digital signal there but thats reaching deeeeep.
BC
IMHO, all that they do is inspect the boards solder joints, resolder any that look bad, repair any circuit board traces that look bad and replace the power relay.
The ABS guy says that he adds a special power surge suppressor but, I have never seen it in person.
NONE of them (NONE) can repair any thing but a power related DTC issue. If they have spare modules, they can replace broken hard parts that are soldered to the board.
If the microprocessor has an issue,,,,, Stick a fork in it,, ITS DONE!!
I'm not sure of your meter reading skills and the ability to properly probe for the correct info. If it were me,,,,,,,,,,,,,,,,,,,,, I would disassemble the main EBTCM connector, look for damaged wires, examine EACH pin and insert a male pin in each female pin and insure that each female pin wasn't spread and make positive that all my basic module power and grounds were 100%.
Once you do that,, it has to be the module. You can get a O scope and read the output of the module and see if theres a digital signal there but thats reaching deeeeep.
BC
Last edited by m88vet; Nov 6, 2012 at 07:35 PM.
Instructor
Joined: May 2008
Posts: 218
Likes: 0
From: LA from the 6th sept till the 10th sept california ( then New Zealand)
ok, what does ebtcm need to come to life? in other words what wires ( input and output ) does it need to no show a NO COMM ?
does it need just pin A B + and F and G- on the connector? which wires does it need for basic function on the serial side of things?
thanks again.......
does it need just pin A B + and F and G- on the connector? which wires does it need for basic function on the serial side of things?
thanks again.......
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
ok, what does ebtcm need to come to life? in other words what wires ( input and output ) does it need to no show a NO COMM ?
does it need just pin A B + and F and G- on the connector? which wires does it need for basic function on the serial side of things?
thanks again.......
does it need just pin A B + and F and G- on the connector? which wires does it need for basic function on the serial side of things?
thanks again.......
You can actually read the Serial Data line for that module with an O Scope and see if there is any output.
If your EBTCM actually has all the power inputs and the proper Grounds,,, it should work.
Your are going to need to be HANDY with the electronic surgical tools (meters and schematics) to make a proper diagnosis.
Bill
Instructor
Joined: May 2008
Posts: 218
Likes: 0
From: LA from the 6th sept till the 10th sept california ( then New Zealand)
thanks bill. hoping later this week to try a 2001 vettes module on mine or visa versa... i will report back with my findings .... if i need a new or replacement module can you recommend a source? thanks ...
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I normally get all my GM ONLY parts from Gene or Patrick at Gm Parts House. www.gmpartshouse.com
Give them a call and see what kind of deal you can get.
Bill
Give them a call and see what kind of deal you can get.
Bill
Instructor
Joined: May 2008
Posts: 218
Likes: 0
From: LA from the 6th sept till the 10th sept california ( then New Zealand)
The EBTCM doesn't tell you that it has NO COMM... Other modules do. The modules look for something called State Of Health messages If a module doesn't send one out. The BCM will report it NO COMM.
You can actually read the Serial Data line for that module with an O Scope and see if there is any output.
If your EBTCM actually has all the power inputs and the proper Grounds,,, it should work.
Your are going to need to be HANDY with the electronic surgical tools (meters and schematics) to make a proper diagnosis.
Bill
You can actually read the Serial Data line for that module with an O Scope and see if there is any output.
If your EBTCM actually has all the power inputs and the proper Grounds,,, it should work.
Your are going to need to be HANDY with the electronic surgical tools (meters and schematics) to make a proper diagnosis.
Bill
Instructor
Joined: May 2008
Posts: 218
Likes: 0
From: LA from the 6th sept till the 10th sept california ( then New Zealand)
OK ...are we out of ideas here? Is the culprit still the EBCM module? I have asked David Ruberg ( speedoguy ) how he tested the module to confirm it works 100% !! i hope to hear from him soon.....
i will copy and paste his reply here ...
My money is still on the EBCM. What else could it be?
still getting codes as follows:
40 BCM B0502 HC
40 BCM B0507 HC
10 PCM PO650 C
10 PCM P1571 HC
58 SDM U1040 HC
i will copy and paste his reply here ...
My money is still on the EBCM. What else could it be?
still getting codes as follows:
40 BCM B0502 HC
40 BCM B0507 HC
10 PCM PO650 C
10 PCM P1571 HC
58 SDM U1040 HC
Instructor
Joined: May 2008
Posts: 218
Likes: 0
From: LA from the 6th sept till the 10th sept california ( then New Zealand)
OK here is David ruberg's reply when asked how does he test the ebcm modules
" hi we test all the stuff on tester that preform all test and fuctions of unit dr "
" hi we test all the stuff on tester that preform all test and fuctions of unit dr "
