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Iver
TwoWaves
Posts: 182 Joined: Mon May 27, 2019 2:55 pm
Post
by Iver » Tue Jul 23, 2019 1:47 pm
Hi
Can anyone help me with ABS & Can Network diagrams for this little beauty.
Many fault codes but NO COMMS with ABS is my starting point.
Many thanks.
Iver
TwoWaves
Posts: 182 Joined: Mon May 27, 2019 2:55 pm
Post
by Iver » Mon Aug 05, 2019 4:23 pm
Getting nowhere fast with this !
I now have the factory diagrams and manual for this. It is a Bosch 8 Premium ESP setup with a 47 pin plug.
I have identified 1.32. & 47 to be the Positives. 16 & 47 are Ground. The all load test well with headlight bulbs.
This car has 4 networks. 2x CAN & K line.
The ABS (NFR), Aero Lifter (NSV) & Power Steering (CSG) are diagnosed over K line.
CSG is only on K Line & Not on any CAN network
ABS, NSV, PCM x2, Yaw Rate, TCM, are on the HS CAN and can be diagnosed.
I can communicate with NSV & CSG but not with ABS, that is my issue.
We have a replacement used ABS module which makes no difference.
Anyone got any ideas with this.
Gaz_13
OneWave
Posts: 11 Joined: Tue Aug 06, 2019 6:49 pm
Post
by Gaz_13 » Wed Aug 07, 2019 8:26 am
Just an observation on the scope capture, the voltage is a little above 10volts. I understand the k line communication is binary and switches between battery voltage and ground. Would a slightly discharged battery affect communications? I understand that you have communications to other ecms on the k line. Tough one...
Iver
TwoWaves
Posts: 182 Joined: Mon May 27, 2019 2:55 pm
Post
by Iver » Wed Aug 07, 2019 8:35 pm
Would a slightly discharged battery affect communications?
Dont know. I would never attempt any diagnosis knowing I have a poor battery. This is being tested with a Battery Support Unit attached set at 13.5v.
K line has a protocol and rules just as every thing in life.
Requests Pull the the voltage closer to Zero than Replies from the slaves .
The first capture is with comms to PAS - Good Comms
The second is with with ABS ECU. Request but no reply..
Can anyone validate this as a fact for me ?
I may put a low amps clamp around the wire today to see which way current is flowing to get belt and braces on this