We found the twisted wire pair on the ABS control module.
1st waveform
Wire colour: yellow-brown
Main voltage: o.5V
Talking voltage: 2.5V
2nd waveform
Wire colour: yellow-black
Main voltage: 1.70V
Talking voltage: 0.3V
When tested with a mulitmeter on the AC setting the readings were 5V and 4.5V.
Compared to the above DC setting the AC is not very accurate as it can't tell you if the signal is switching. It reads the wires both front and back so to say so it doesn't know the difference when it is switched.
Aliasing is when you have a jagged effect of a smooth line or curve. Looks like zigzags on an oscilliscope.
You can tell that the waveform is not aliasing by use of the oscilliscope so you can actually see what the pattern is. You may have to play with the settings on the oscilliscope to remove the aliasing.
Scan tool observations
We used the Autoboss scan tool on the Range Rover.
The different functions on the scan tool to examine the CAN system were:
Control unit version
Fault codes
Acutal values(all select)
Actual values(manual select)
Systems controlled by the CAN:
Wiring diagram exercise
This wiring diagram shows most of the controls that you can operate as the passenger or driver such as the cruise control, air con and power windows.
The highspeed and low speed comes from the ECM on page 2.
The gateway is in the dahsboard control unit.
The system can be divided into each separate modules, this will help diagnosis by separating the problem from the CAN. Then by process of elimination you can figure out which module is bringing the CAN down.
The power window module would go to sleep as it is not always needed.
Cant measure the voltage or amperage on this circuit...
There are a few things that you have misunderstood here. the High speed CAN comes from the ECM but it is the high and low signal NOT speed. Just a calcification the gate way is the Gauge control unit, best to use the right terms for each wiring diagram.It would also have been good to explain what the gate way does. How and were can the CAN system be divided? you should have explained how this helps also.Also You have not listed all of the nodes that are connected to the low speed CAN what their pins and wire colour would have been good also. Again this is just feed back, not asking you to add more
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