Sunday, November 27, 2011

Can systems

Controlled Area Network Board




Using the dual trace feature on the oscilloscope capture the full pattern of the H-CAN and L-CAN. Identify which wire is the H-CAN and which is for the L-CAN.
Chanel one is high can and channel 2 is low- can and they both connected to the positone .


On your capture also identify were the data pattern starts and finishes.


Describe the relationship between the two patterns and their base voltages (what volts when not switched)

They both mirrior each other the high and the low can in the picture above the yellow patterns are the low can they start off normal and they drop down but blue one is high can patterns they start off normal and then it jumps up and this test was done without any wipers or light on . so this was done standard.
For each of the following inputs capture the pattern and identify were it changes in relation to the original pattern:

Right indicator

 
Rear wiper

Reverse lights

Fuel pump

Using the wiring diagram and CAN board Identify the input /output pins, wire colours, Relay or transistor for the right hand indicator and rear wiper:

OK i choose right hand indicator so its starts off with pin 7 it goes to resistor 5 after that it goes straight ti chip 6 -vp18f258/ra4/tocki.
Then it comes out through can-high and can- low straight though channel 1 and then it foes out through con 1 and 2 though 4 and 5 then it goes to the can ship entering 7 and 6 goes out through 4 all the way straight to 12 /rxcan/n which is the iC chip then it goes through 5 pass through resistor 32.
After that ti enters the optocaupler  the it goes out passes through pull down resistor goes to the transistor then it travels to the connector output 5.


Using the wiring diagram identify both voltage regulators that resemble the one that you built in TTEC4824. Note all the input pins and were the outputs are connected to.

U17805 output pin20 + ve
                 
               input Pin1 connector block input 12 v close to power supply to all the chips.

U27805    Output pin 14 VDD

                Input pin2 connector block input supply 12v before OP amp.


Using the wiring diagram follow one circuit though from the input to the output. Note all the inputs/IC/relays/transistors and describe how the circuit operates

So i start off with the rear wipers it goes from Pin 8, R14b R14a, then to u14bc5471045 after that it goes to pin 10 gp6/clkout straight pin 12  rx can /nc,  
Then pin 13 TX can /txcan , uc5350n Dil , cab Hpn 7 can low pin 6 then to pin 7  which is can low to pin 6 , and pin 4 4h pin 5l 
Then connector 3 connector 2 foes to pin1 can h and pin 1 can low pin 6 CAN low pin 7 can high / TXD pin 1 ,pxd pin 4 uc535On D/L, vp18f258, pin 23 RB2/ cantx pin 24 R133/ cab RX ,RB4 2D7 Zener 5v,10k 
R15,R8 14500, pin9 rear wiper.
This was really hard to understand but this how it goes accrodling to the wiring diagram on moodle or the one we got given in class but i hope you can understand it and the reason we get this to do class is to let us understand how to how to read wiring diagrams and get better in it because we would need to know all this stuff before we can out and work at some auto electrical shop.

 CAN – Multiplexing 

The job we had to was check and test out the CAN systems on Range Rover 2001 model . So to test this out we had to oscilloscope to measure voltages and get the wave forms and also using the scan tool to get the codes the reason for having a CAN system is to reduce of having heaps of wires going to each actuator but now there is only 2 wires going between the nodes makes the job alot easier and you wont have heaps of wires going everywhere .

CAN Waveform on Oscilloscope  


1.1  Locate the Range Rover or other suitable vehicle with easily accessible CAN system twisted wires.  Which vehicle do you have? (Year, make and model)

The car we were doing it on was 2001 model Range Rover.


1.2  Locate a twisted wire pair. Describe where the wires are located:  

The rear ABS module



1.3  Record the waveform of one of the wires below: (Make sure your time is small enough so you don’t have “aliasing”.)

 
Colour of wire:Yellow/browen

Time per division:10 Us

Voltage per division: 2V


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


Colour of wire:Yellow/Browen

Time per division:10 Us

Voltage per division: 2V


is aliasing? Describe it.  

In signal processing and related disciplines, aliasing refers to an effect that causes different signals to become indistinguishable (or aliases of one another) when sampled. It also refers to the distortion or artifact that results when the signal reconstructed from samples is different from the original continuous signal.
i didnt know the meaning of this word so i went and searched it up Google and that what i came up with  and here is the reference


http://en.wikipedia.org/wiki/Aliasing

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

2.35 V

What is the other voltage on the line, when the voltage is pulled up or down to “talk” ?

0.34V

 the 1.4  waveform above, what is the main voltage on the line? 
2.56V

What is the voltage on the line, when the voltage is pulled up or down to “talk”?

0.29V

Observe the signals in 1.3 and 1.4 above with a voltmeter. Compare it with DC volts or AC volts setting. Which setting would tell you if the signal is switching. Explain

5.5 V/AC         0.4 V/AC

When you set the voltmeter on the AV volts you can see the signal is switching that means the AC volts are pulled up and down more clear then the DC volts



Scan Tool Observations 

  Find a vehicle that will show CAN system operation on a scan tool (such as the Range Rover.

 The vehicle we were using was Range Rover 2001 model and the scan tool we had was Auto boss it wasn't that good because it was really slow but it still does the job but just takes a bit longer then you expect.

What different functions are available on the scan tool to examine the CAN system?

Zke/Gm( central body electronics/GM base module
 The was found in auto boss scan tool when we were searching and this is what it does so it controls the unit version fault codes also the actual values (select all) actual values and (manual select) Actuation.



List the different systems that are controlled by CAN? (note which are high speed and which are low speed)

In the picture blew there are other different types of systems that are controlled by the CAN.





Locate a system that goes to “sleep” after a short time.  What is it? 

One of the Can lines-low can lines.
 also i got a short clip showing when the system goes to sleep and after a short time 
here it is


What voltage do you see when it is “awake”?    2.36V

            What voltage do you see when it is “asleep”? 0.3V

            On what wire do you see this voltage change?Yellow / brown


Honda Multiplexing

The task we had for Honda multiplexing board the parts were from Honda accord and they from 1196 to 2002  the board used 2 nodes which was from honda Can system we did these to help us understand more and more also this is practical so when you do something practical you understand it more and the more you do it the more you get better at it or understand Can system diagnostics

This multiplex system was used for body controlled functions on 1996 to 2002 Honda
accord and 1996 onward prelude. It utilises three nodes (control units) drivers door,drivers
side and passenger side.The testing procedure is divided in to three sections
Communication lines and nodes from mode 1,inputs from mode 2. If the system passes
these tests from mode 1 and 2, but is still faulty the problem is likely to be an output.


 Using the wiring diagram identify the plugs/ pins and wire colours for the communication lines between the nodes.

Door side is brown which is A15 - A2
Passenger pink - B1-B9 

Using the wiring diagram identify the plugs/ pins and wire colours for the Earths and
voltage supply lines between the nodes. 

Black wires are earth so positive - pin A1 (Door) 

Ask your instructor to create a fault in the unit
Describe in detail how this fault is affecting the normal operation of this system.


The driver side rear door light don't work which means that the door is open and it wouldn't turn on like all the other ones.  

 Using the wiring diagram analyze the fault and describe in detail what may be causing
this fault.


There could be a bad ground that's causing it or there is break from the multiple to the rear door side switch. 

After reading the manual put the system in to test mode 1. Note the codes (if any) and
possible faults that the system gives you. 


i check it all and there was no codes so no faults.

Do the codes concur with what you thought the problem might be from question 4,
explain. 


Also for this one there was no codes coming up  

Go to step 5, can you conduct this test? Why /why not. 

yes all the lines were good condition no corrosion or any damage .

Conduct the tests in step 6, what is your results and conclusions. 

All the communication line The door - drivers brown wire was good so its got 5.2 volts and within the specs of 3.5 - 9.5
 so drivers passenger was also good which was 5.20 specs were 3.0 to 10 pink wire  .

Put the system in to diagnostic Mode 2, conduct the input tests and note the results. 

everything was in perfect condition apart from the driver side rear door which did not beeb causing a fault .

Explain your results and conclusions, Does it concur with your diagnosis from question
4?


Its got the input the switch could be faulty as all the others were working but the drivers side rear doesn't we tested them all the communication lines and they all good . 
I also had to put the system in to sleep mode and measure the time it take so the results i got was 4.03 volts and 10 seconds and .66 amps and the last one 018 amp. 

  
 

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