CAN-Multiplex Worksheet

Colour of the wire Yellow Black
Time per division: 20us
Voltage per division: 1V

1.4 Record the waveform of the other wire in the twisted pair:

Colour of the wire:  Yellow brown
Time per division: 20us
Voltage per division: 1V

In the following graph there is a pattern for both Yellow Black and Yellow Brown CAN wires at same time on oscilloscope:

1.5
Q.  What is aliasing? describe it.
A.  It is the effect that create the distortion in the signals and causes different continuous signals to indistinguishable when taking on the oscilloscope. (www.wordiq.com)

1.6
Q. How do you know these waveforms are not aliasing?
A. From the first two oscilloscope graphs, we can see the see the distinguished waveform and there is not deformation in the wave pattern.

1.7
In the 1.3 waveform above, what is the main voltage on the line?
About 3.2 V
Q. What is the other voltage on the line, when the voltage is pulled up or down to talk?
A. About 2.2 V

1.8
In the 1.4 waveform above, what is the main voltage on the line?
1.3 V

Q. What is the voltage on the line, when the voltage in pulled up or down to talk?
A. 2.5V

1.9
Observe the signal in 1.3 and 1.4 above with a voltmeter.
1.3 one's is 2.37
1.4 one's is 2.65

2.3 List the different systems that are controlled by CAN?

3.0 Wiring Diagram Excercise:

3.2  Body computer no subsystem (2.4L)

3.3  High speed system are in ECU/ PCM. The pin no. E24 (Red colour) and E11(White) are high speed wires of the system.

3.4  Seat belt input, RR door switch, RF door switch, LR door switch, LF door switch and many more in underdash fuse/relay box 

3.5  The location of the gateway is "Gauge Control Module" in the diagram.

3.6  The system can be diagnose at "Multiplex Control Inspection Connector".

3.7 We connect the Scan tool at Multiplex Control Inspection Connector to diagnose the system. From here we can diagnose every where because the system is communicating   with each other by CAN high and CAN low. Any module having fault will be detected at Multiplex Control Inspection Connector.

3.8 Locate a system that goes to "sleep" after a short time. What is it?

      Alarm Bonnet Switch

3.9 

Q. What voltage do you see when it is "awake"?

A. 0.29 V (DC)

Q. What voltage do you see when it is "asleep"?

A. 0.21 V

Q. On what wire do you see this change?

A. yellow brown (non CAN)

3.10 Amp Drain:

Measure the amp drain at the battery when the system is asleep

0.92 A after 5 minutes

0.6 A after 10 minutes

Q. How long did it take the system to go to sleep?

A. 5 minutes

Q. What made the system "wake up"

A. Alarm Bonnet Switch.