PicoScope 7 Automotive
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Unknown Protocol
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sigoaprendiendo
- TwoWaves
- Posts: 54
- Joined: Tue Aug 05, 2014 8:58 pm
- Location: Slovenija
Unknown Protocol
Hi everybody.
I recently have an issue with a non familiar DTC, this is U014089 where the electronic brake module lost communication with the master main module in the cabin just beneath the fuse box.
The patient is a Volvo Truck, FH4 model.
After doing a programming job for the main module interface control unit the problem was solved, after a short ride to check the results another DTC showed up, this time is:
C107294 Foot Brake Module Electrical Link Unexpected Operation
The conditions for this trouble code to set up are internal e.g. a switch to wake-up the electronic brake module in case the driver presses the brake the pedal without the ignition, as far as I know there are two additional inductive and two non-contact sensors to monitor the plunger rod stroke of the foot brake pedal which activates the foot brake module.
According to the technical information the failure events are:
*Two stroke sensors are not reporting the same values or
*The wake-up position switch does not match the measured stroke value.
In short, after hooking up my pico to the pedal sensor and the brake module it self I got the same wave forms results. Then after replacing the foot brake module, erased the fault codes and take a short ride, the fault is gone. We have a fix. Trying to get an after repair new wave form I got exactly the same patterns, so now is clear that the internal hardware in the foot brake pedal is capable of sending real good and reliable data through the two communication lines.
Now my question is, I need to decode the signal with Pico software in order to evaluate the IDs and all the relevant information from the modules, but I don't know what kind of signal is, in my eyes it has a clock and a data signal. Here you are a picture from the sensor connector.
Waveform colors:
Blue: Signal 1
Red: Signal 2
Green: Ground
Gold: Supply battery voltage
And this a view from the sensor connector:
I recently have an issue with a non familiar DTC, this is U014089 where the electronic brake module lost communication with the master main module in the cabin just beneath the fuse box.
The patient is a Volvo Truck, FH4 model.
After doing a programming job for the main module interface control unit the problem was solved, after a short ride to check the results another DTC showed up, this time is:
C107294 Foot Brake Module Electrical Link Unexpected Operation
The conditions for this trouble code to set up are internal e.g. a switch to wake-up the electronic brake module in case the driver presses the brake the pedal without the ignition, as far as I know there are two additional inductive and two non-contact sensors to monitor the plunger rod stroke of the foot brake pedal which activates the foot brake module.
According to the technical information the failure events are:
*Two stroke sensors are not reporting the same values or
*The wake-up position switch does not match the measured stroke value.
In short, after hooking up my pico to the pedal sensor and the brake module it self I got the same wave forms results. Then after replacing the foot brake module, erased the fault codes and take a short ride, the fault is gone. We have a fix. Trying to get an after repair new wave form I got exactly the same patterns, so now is clear that the internal hardware in the foot brake pedal is capable of sending real good and reliable data through the two communication lines.
Now my question is, I need to decode the signal with Pico software in order to evaluate the IDs and all the relevant information from the modules, but I don't know what kind of signal is, in my eyes it has a clock and a data signal. Here you are a picture from the sensor connector.
Blue: Signal 1
Red: Signal 2
Green: Ground
Gold: Supply battery voltage
And this a view from the sensor connector:
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Steve Smith
- Pico Staff Member
- Posts: 1594
- Joined: Sun Aug 25, 2013 7:22 am
Re: Unknown Protocol
Hello and thank you for the post
Looking at the image provided the sample rate appears low which ultimately affects the function of the decoder, if decoding is required
Would you have the psdata files for your before and after fix captures?
If you can post here we can take a look and attempt to unravel the mystery
I am intrigued that "C107294 Foot Brake Module Electrical Link Unexpected Operation" only appeared after reprogramming, were there any physical symptoms associated with this fault code (i.e. drivability/brake operation?)
Take care.....Steve
Looking at the image provided the sample rate appears low which ultimately affects the function of the decoder, if decoding is required
Would you have the psdata files for your before and after fix captures?
If you can post here we can take a look and attempt to unravel the mystery
I am intrigued that "C107294 Foot Brake Module Electrical Link Unexpected Operation" only appeared after reprogramming, were there any physical symptoms associated with this fault code (i.e. drivability/brake operation?)
Take care.....Steve
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sigoaprendiendo
- TwoWaves
- Posts: 54
- Joined: Tue Aug 05, 2014 8:58 pm
- Location: Slovenija
Re: Unknown Protocol
Hi everybody and Thanks to Steve for your answer
This is the file I got before replacing the Foot Brake Module:
And this is the waveform after fitting a new one:
As for your question about the last DTC C107294, Unexpected operation; I think I didn't get it before because the EBS (Electronic Brake System module) wasn't able to directly communicate with the main module interface through the Chassis subnet, but only through the CAN network J1939 (there is another network J2284 for another modules in this truck) and this last module(the main interface) is with the OBD diagnostic connector linked to, so the OBD connector don't have direct access to this two CAN networks and and any other subnet, this is my theory about this DTC absence, but not really sure about that. Volvo Trucks diagnostic software has plenty of pitfalls in within.
Another thing to consider is that this foot brake module has four hoses connected to it. Two of them come from individual air reservoir for front and rear brake. The other two are outlets for front and rear break individually. Brake system can work electronically or in back-up mode (pneumatically with this four hoses) in case of electrical problems.
I will try to get more waveforms suitable for decoding purposes is we need it
Kind regards
Dario
This is the file I got before replacing the Foot Brake Module:
And this is the waveform after fitting a new one:
As for your question about the last DTC C107294, Unexpected operation; I think I didn't get it before because the EBS (Electronic Brake System module) wasn't able to directly communicate with the main module interface through the Chassis subnet, but only through the CAN network J1939 (there is another network J2284 for another modules in this truck) and this last module(the main interface) is with the OBD diagnostic connector linked to, so the OBD connector don't have direct access to this two CAN networks and and any other subnet, this is my theory about this DTC absence, but not really sure about that. Volvo Trucks diagnostic software has plenty of pitfalls in within.
Another thing to consider is that this foot brake module has four hoses connected to it. Two of them come from individual air reservoir for front and rear brake. The other two are outlets for front and rear break individually. Brake system can work electronically or in back-up mode (pneumatically with this four hoses) in case of electrical problems.
I will try to get more waveforms suitable for decoding purposes is we need it
Kind regards
Dario
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Steve Smith
- Pico Staff Member
- Posts: 1594
- Joined: Sun Aug 25, 2013 7:22 am
Re: Unknown Protocol
Hello again Dario and thank you for the feedback and psdata files
I can now see sample rate is not our issue here and so no worries there.
A little more time across the screen (200 ms/div) with a clear change of pedal state (press and release) midway through one buffer would be useful but for now not essential
The protocol does appear unique to either the VM or the manufacturer of the device (Brake Module)
I can see we have repetition in Channel B and changing packets on Channel A but need to understand the rules surrounding the protocol structure in order to decode
I have spoken to Ben who will make some inquires with a number of HGV "contacts" and together we can hopefully pull out data we can convert into readable values
I will be in touch ASAP
Take care.....Steve
I can now see sample rate is not our issue here and so no worries there.
A little more time across the screen (200 ms/div) with a clear change of pedal state (press and release) midway through one buffer would be useful but for now not essential
The protocol does appear unique to either the VM or the manufacturer of the device (Brake Module)
I can see we have repetition in Channel B and changing packets on Channel A but need to understand the rules surrounding the protocol structure in order to decode
I have spoken to Ben who will make some inquires with a number of HGV "contacts" and together we can hopefully pull out data we can convert into readable values
I will be in touch ASAP
Take care.....Steve
Re: Unknown Protocol
Knorr bremse uses 5 V TI CAN in some of their modules.
Maybe someone can make head and tails of these, if indeed applicable:
https://www.ti.com/lit/ds/symlink/sn65h ... 1464873541
https://n0c357rmy1njbuit2friqwu.blob.co ... EN_005.pdf
Maybe someone can make head and tails of these, if indeed applicable:
https://www.ti.com/lit/ds/symlink/sn65h ... 1464873541
https://n0c357rmy1njbuit2friqwu.blob.co ... EN_005.pdf
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sigoaprendiendo
- TwoWaves
- Posts: 54
- Joined: Tue Aug 05, 2014 8:58 pm
- Location: Slovenija
Re: Unknown Protocol
Super. Will be interesting if you can add this protocol to PS7
This module is not exclusive to Volvo, Renault and maybe more Trucks-Makes share the same part. Here you are a pic from the module Volvo and Renault use.
Kind regards
Dario
This module is not exclusive to Volvo, Renault and maybe more Trucks-Makes share the same part. Here you are a pic from the module Volvo and Renault use.
Kind regards
Dario
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sigoaprendiendo
- TwoWaves
- Posts: 54
- Joined: Tue Aug 05, 2014 8:58 pm
- Location: Slovenija
Re: Unknown Protocol
Hi Liviuliviu2004 wrote: ↑Fri Aug 26, 2022 12:35 pmKnorr bremse uses 5 V TI CAN in some of their modules.
https://www.ti.com/lit/ds/symlink/sn65h ... 1464873541
https://n0c357rmy1njbuit2friqwu.blob.co ... EN_005.pdf
Very interesting documents. Thanks for sharing this information
Kind regards