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Got it, so eventually checking again my DLC (OBD2 port in car) at Pin 12 and 13 with voltmeter will give me valid information?
You check pins 12 and 13 with the ohm meter with the battery DISCONNECTED and you should see 60 ohms…if a wire is broken you will see 120 ohms…with IGNITION on you will see those voltages…a good mechanic with electrical experience can diagnose this…dealerships here don’t diagnose because all they do is change parts…electrical systems knowledge is not changing oil and brakes…I enjoy electrical diagnostics because I have a pretty solid foundation and I still do this type of training whether in person or online.
You check pins 12 and 13 with the ohm meter with the battery DISCONNECTED and you should see 60 ohms…if a wire is broken you will see 120 ohms…with IGNITION on you will see those voltages…a good mechanic with electrical experience can diagnose this…dealerships here don’t diagnose because all they do is change parts…electrical systems knowledge is not changing oil and brakes…I enjoy electrical diagnostics because I have a pretty solid foundation and I still do this type of training whether in person or online.
Awesome, today i checked with battery connected, maybe that was the issue.
Will update you again as far the information you needed tomorrow.
thanks really alot!
Awesome, today i checked with battery connected, maybe that was the issue.
Will update you again as far the information you needed tomorrow.
thanks really alot!
Battery MUST be disconnected to measure for the 60 or 120 ohms !!…2 part video if you want to watch !!
[QUOTE=C5 Diag;1608227095]Battery MUST be disconnected to measure for the 60 or 120 ohms !!…2 part video if you want.
Hi
this morning i checked as per your direction the resistance in the PIN 12 and 13, and the Volt aswell.
The test resulted in a correct resistance value of 1 (to be multiplied by 40) so i guess around 60 Ohms becauseif it was 120 i would have got 2 or 3, and a good voltage in both CAN PIN of 2,6v.
What is the next thing i could check to hunt down the problem?
Thanks
below you can see my RPO codes,
Also, the error i have in the EBCM : U0422-00 (Invalid Data Received from the Chassis Module A) is current and doesn't go away even after i clear all the DTCs, and is the Only DTC.
Any guess?
Last edited by s n v f f; Oct 5, 2024 at 08:37 AM.
Battery MUST be disconnected to measure for the 60 or 120 ohms !!…2 part video if you want.
Hi
this morning i checked as per your direction the resistance in the PIN 12 and 13, and the Volt aswell.
The test resulted in a correct resistance value of 1 (to be multiplied by 40) so i guess around 60 Ohms becauseif it was 120 i would have got 2 or 3, and a good voltage in both CAN PIN of 2,6v.
What is the next thing i could check to hunt down the problem?
Thanks
below you can see my RPO codes,
Can you take a picture of your DVOM and your reading…you should not have to multiply anything….you have G96 but that is not an issue right now…think you need a new DVOM because you have to trust your equipment.
Can you take a picture of your DVOM and your reading…you should not have to multiply anything….you have G96 but that is not an issue right now…think you need a new DVOM because you have to trust your equipment.
Can you take a picture of your reading ??…I would try another measurement with another DVOM…don’t worry about the “400” number before your ohm symbol !!…the reading you get is what you get…what does your ohm meter read with the leads held apart and when touched together ??…can you communicate with the Chassis Control Module, Suspension Control Module, and Power Steering Control Module and the EBCM ??…if you can view “Live Data” for each module that means you can communicate with it…I think an electrical shop is your best bet right now.
Can you take a picture of your reading ??…I would try another measurement with another DVOM…don’t worry about the “400” number before your ohm symbol !!…the reading you get is what you get…what does your ohm meter read with the leads held apart and when touched together ??…can you communicate with the Chassis Control Module, Suspension Control Module, and Power Steering Control Module and the EBCM ??…if you can view “Live Data” for each module that means you can communicate with it…I think an electrical shop is your best bet right now.
While touching the red and black lead togheter i have a "0.02" value, and while Apart i have a "0L" value.
Also i tried again the test on the Pin 12 and 13 with the battery disconnected, and it gives "0.02", so it is a zero right?
meaning a short in the CANBUS?
Can you take a picture of your reading ??…I would try another measurement with another DVOM…don’t worry about the “400” number before your ohm symbol !!…the reading you get is what you get…what does your ohm meter read with the leads held apart and when touched together ??…can you communicate with the Chassis Control Module, Suspension Control Module, and Power Steering Control Module and the EBCM ??…if you can view “Live Data” for each module that means you can communicate with it…I think an electrical shop is your best bet right now.
Also, I'm able to access all the modules, including the 2 that doesn't communicate with my Diagnostic (for example i moved the exhaust flap in the CCM (this one is communicating) or moved the read differential pistons for the ELSD in the RDCCM that is not communicating) so I am able to access the modules, yes the SWASM and RDCCM result Not Communicating, and I have the above said constant error in the EBCM from a non valid data coming from the CCM
While touching the red and black lead togheter i have a "0.02" value, and while Apart i have a "0L" value.
Also i tried again the test on the Pin 12 and 13 with the battery disconnected, and it gives "0.02", so it is a zero right?
meaning a short in the CANBUS?
Yes, that would be a short…what do you read if you put one lead on pin 12 and other on a good ground such as the driver door hinge bolts ??…do the same on pin 13….like I mentioned anything beyond this will require an electrical specialist.
Yes, that would be a short…what do you read if you put one lead on pin 12 and other on a good ground such as the driver door hinge bolts ??…do the same on pin 13….like I mentioned anything beyond this will require an electrical specialist.
Anytime you take a resistance measurement on the CAN bus unless you let the modules “go to sleep” you should disconnect the battery or you will get incorrect results.
Will get back about it tomorrow as i left the garage where the Corvette is.
Another thing, i don't know if related or not.
currently my car is sitting with a (99% sure) broken rear spyder gear in the differential waiting for the new carrier to arrive next week.
can this 2 things be related? By logic no in my opinion, but the mechanical failure of the differential and the rear differential clutch control module (RDCCM) not communicating as well? It's strange.
I don’t know what connectors might have been disconnected right now so I could not tell you…nothing “mechanical” removed from the car would not affect the electrical side…below is the resistance readings I see on my CAN high and low to ground…7.87 K Ohms which is 7,870 Ohms…I don’t have a Chassis Expansion Bus but you should see high resistance readings…maybe you should trade in your C7 for a Ferrari or Lamborghini…LOL !!…those cars are what I cut my teeth on when I was young and first started working on cars…my friends Dad had a body shop and garage specializing in those cars and I worked there for a few years…only wish I had the money to buy a 1973 Daytona Ferrari that was for sale back then…loved the sound of those V-12’s !!…I could have been very rich today if I sold it today…Ciao !!
I don’t know what connectors might have been disconnected right now so I could not tell you…nothing “mechanical” removed from the car would not affect the electrical side…below is the resistance readings I see on my CAN high and low to ground…7.87 K Ohms which is 7,870 Ohms…I don’t have a Chassis Expansion Bus but you should see high resistance readings…maybe you should trade in your C7 for a Ferrari or Lamborghini…LOL !!…those cars are what I cut my teeth on when I was young and first started working on cars…my friends Dad had a body shop and garage specializing in those cars and I worked there for a few years…only wish I had the money to buy a 1973 Daytona Ferrari that was for sale back then…loved the sound of those V-12’s !!…I could have been very rich today if I sold it today…Ciao !!
At the moment nothing has been removed from the car.
She's sitting as she has been towed home since the mechanical failure.
the only thing i found bizarre is that the rear differential failed gear and at the same time the CAN communication loss of it's module.
now, I'm not 100% sure those 2 thing happened together as i started diagnosing after the mechanical failure, but I'm pretty confident the car could not be driven with those modules non communicating, or not?
i had in the months few service rea axle messages randomly, but I've alway thought related to maybe a low battery level seen that i started to use a tender just 1 or 2 months ago, and after that i had never again rear axle messages until the mechanical failure.
At the moment nothing has been removed from the car.
She's sitting as she has been towed home since the mechanical failure.
the only thing i found bizarre is that the rear differential failed gear and at the same time the CAN communication loss of it's module.
now, I'm not 100% sure those 2 thing happened together as i started diagnosing after the mechanical failure, but I'm pretty confident the car could not be driven with those modules non communicating, or not?
i had in the months few service rea axle messages randomly, but I've alway thought related to maybe a low battery level seen that i started to use a tender just 1 or 2 months ago, and after that i had never again rear axle messages until the mechanical failure.
If the Differential Clutch has its own Module you would have to check the electrical connections at the differential…I don’t know how bad of a mechanical failure it was but it’s good we know “the rest of the story”…I would wait until the repair is made, all electrical connectors inspected and reinstalled and then a complete scan of all modules.
If the Differential Clutch has its own Module you would have to check the electrical connections at the differential…I don’t know how bad of a mechanical failure it was but it’s good we know “the rest of the story”…I would wait until the repair is made, all electrical connectors inspected and reinstalled and then a complete scan of all modules.
Already done, both connectors of the rear differential module were good and tight, i unplugged them, cleaned with contact spray and installed back, not the issue.
