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While diagnosing my 14 C7 Z51 M7 with GDS2,
I've noticed that the "Rear Differential Clutch Module" and the "Steering Wheel Angle Sensor Module" result Not Communicating.
Along with that I've another (probably related) error, in the EBCM : U0422-00
Both apparenrly are on DLC Pin 12, 13.
I've checked all the Fuse, Relays all fine.
Harness or wiring issue maybe? Some shorts or interrupion on the wires that run across the tunnel?
Since you know those modules are on pins 12 and 13 are you using an information bus wiring diagram from somewhere ??
Thanks for replying,
actually not, but the GDS2 clearly says that both modules are on DLC Pin 13 and 12.
having that information i went right after to check the Ohms between those 2 pins on the OBD2 port, and i had "0" as result, I'm not an expert, but could it mean there is a short?
But, if i check the DLC diagram, it says that Pin 12 and 13 are Not Used..
if someone can clarify this as well, i can't understand.
Last edited by s n v f f; Oct 4, 2024 at 02:16 PM.
Thanks for replying,
actually not, but the GDS2 clearly says that both modules are on DLC Pin 13 and 12.
You have a DVOM and know how to use it ?? ...also do you know how to read a wiring diagram ??...also do you have RPO code G96 which is a Chassis Control Module ??...RPO codes in the glove box.
I tried to check the Ohms between the 2 Pin 12 and 13, and I had "0" as result, (means that there is a short? I'm not an expert, i expected 60 for an undamaged line).
By the way, looking at the DLC diagram, Pin 12 and 13 appearing "Not in Use".
can someone clarify this?
You have a DVOM and know how to use it ?? ...also do you know how to read a wiring diagram ??...also do you have RPO code G96 which is a Chassis Control Module ??...RPO codes in the glove box.
I have no access at the Car right now but i will be able tomorrow to send you that details.
thanks
I received your PM but I don't have that APP...I understand your predicament and unfortunately diagnosing this issue over the Internet is next to impossible....most likely a broken wire depending on if you see 120 or 60 ohms between pins 12 and 13...you need to know where the connectors are such as X201,X202, X350,and X311 are located...maybe there are some electrical specialists where you live....some DVOM's say OL or 1 when the leads are not touching each other denoting an open circuit...99.99% of mechanics and dealerships here in this country would find it hard to diagnose this...I don't know where you are getting your service info from but that is the first step.
On the right you can see where pins 12 and 13 are and I highlighted the 2 modules you can’t communicate with…if you don’t have a chassis control module you just bypass that module…where you see -G96 means it not a module in the car…as you can see from the steering wheel angle sensor the wiring goes to the Rear Differential Clutch Module if you don’t have G96.
On the right you can see where pins 12 and 13 are and I highlighted the 2 modules you can’t communicate with…if you don’t have a chassis control module you just bypass that module…where you see -G96 means it not a module in the car…as you can see from the steering wheel angle sensor the wiring goes to the Rear Differential Clutch Module if you don’t have G96.
Thank you so much for the extremely helpful information.
I'm 99% sure my car has a Chassi Control Module (the one with 2 connectors) in the trunk under th carpet.
too bad I'm not able to read your diagram, but i will try to understand it.
so you confirmed that in my OBD2 port (above the pedals) the Pin 12 and 13 are actually in use and has to give a 60 value if working properly? Or 120 if not? Mine actually gave 0 for some reason.
On the right you can see where pins 12 and 13 are and I highlighted the 2 modules you can’t communicate with…if you don’t have a chassis control module you just bypass that module…where you see -G96 means it not a module in the car…as you can see from the steering wheel angle sensor the wiring goes to the Rear Differential Clutch Module if you don’t have G96.
Also, the wiring that brings the CAN communication between all that modules is the one that run from the front of the car to the back in the tunnel area? See attached image for reference
Thank you so much for the extremely helpful information.
I'm 99% sure my car has a Chassi Control Module (the one with 2 connectors) in the trunk under th carpet.
too bad I'm not able to read your diagram, but i will try to understand it.
so you confirmed that in my OBD2 port (above the pedals) the Pin 12 and 13 are actually in use and has to give a 60 value if working properly? Or 120 if not? Mine actually gave 0 for some reason.
Just look at the RPO codes to see if you have that module…the 2 wires just goes in and out of each module…I posted a picture of your 2014 DLC and you can see you have this Chassis Expansion Bus…if wiring is good from one end to the other you will see 60 ohms…if a wire is broken you will see 120 ohms.
Also, the wiring that brings the CAN communication between all that modules is the one that run from the front of the car to the back in the tunnel area? See attached image for reference
No, but I've just purchased one (the one you see in the picture) eventually if it includes the problem, i would have my mechanic replacing it in full that would be easier than finding a short.
Is that the wiring that brings the CAN communication to the modules? Or i need a different one?
No, but I've just purchased one (the one you see in the picture) eventually if it includes the problem, i would have my mechanic replacing it in full that would be easier than finding a short.
Is that the wiring that brings the CAN communication to the modules? Or i need a different one?
Just look at the RPO codes to see if you have that module…the 2 wires just goes in and out of each module…I posted a picture of your 2014 DLC and you can see you have this Chassis Expansion Bus…if wiring is good from one end to the other you will see 60 ohms…if a wire is broken you will see 120 ohms.
Tomorrow as i will have access to the car i will send the RPO info needed, thanks
No, but I've just purchased one (the one you see in the picture) eventually if it includes the problem, i would have my mechanic replacing it in full that would be easier than finding a short.
Is that the wiring that brings the CAN communication to the modules? Or i need a different one?
Depending what you see with an ohm meter and voltmeter will tell you whether you have an open or the CAN wires are shorted to each other.
CAN missing communication for 2 modules
