Connect ECU to Cluster on bench

Hello.
Looking to connect a immo3 ECU to cluster on the bench for testing.

Looking to know which CAN high and CAN low to use on the cluster end.

On this pinout there is CAN in and out? Which ones would you use? or does one go to the ECU and one go the the OBD?

These are 2 options I have though of. If anyone knows if one of these is correct or if both are wrong any advice would be great

Thanks

In this way Im not sure what CAn to use for the cluster. It has both in and out.
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In this way im not sure if the CAN come in from the OBD or in from the ECU?
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Here is the pinout im going by for the cluster CAN lines in and out.

2k2 model, Golf/Jetta (Bora) - euro:
32-pin, green:
1 - vacant
2 - reading coil for immo 1
3 - warning lamp for side lights
4 - data bus (CAN), screening for input signals
5 - W-wire
6 - washer fluid shortage
7 - brake pad wear
8 - vacant (CAN + High) connect to T23/9 of the ccm**pre 2002, Immo II cars only.
9 - vacant (CAN - Low) connect to T23/6 of the ccm** pre 2002, Immo II cars only.
10 - vacant
11 - signal for vehicle stationary
12 - aircon system cut-off
13 - warning lamp for hand brake
14 - warning lamp for ASR/ESP
15 - vacant
16 - vacant
17 - reading coil for immo 2
18 - oil temp & level warning signals
19 - data bus (CAN), high input signal
20 - data bus (CAN), low input signal
21 - vacant
22 - bonnet switch input signal (connect to T15/5 of the CCM)
23 - MFI call up button, top
24 - MFI call up button, bottom
25 - MFI memory switch - reset
26 - ambient temp input signal
27 - data bus (CAN), high output signal
28 - data bus (CAN), low output signal
29 - vacant
30 - clock**
31 - data**
32 - enable**

I have found the following

ECU CAN Connections

edc15________Cluster
J248 pin 6 ----> T32a pin 20 CAN LOW input
J248 pin 7 ----> T32a pin 19 CAN HIGH input

ME7x
J248 pin 58 ----> T32a pin 20 CAN LOW input
J248 pin 60 ----> T32a pin 19 CAN HIGH input

So now I am assuming the following, adn if someone can confirm that would be great

The can outputs in the cluster go to the OBD
and does the kline need to be connected to all devices. ECU.,Cluster and OBD.
Or just to the cluster?

Thanks Guys

I have tried with the connections above and still cannot adapt a key on the bench.

There must be something connected wrong or missing.

I am wondering where pin4 in the cluster connects.

Can data bus input signal. Pin 4?

Do you have terminators at the end of your CAN network?

No,
I just have the leads connected directly from the cluster to the ECU.

You should have 120 ohm resistors on either end ( it may be in the cluster).

When off the resistance should be 60 ohm between the lines with everything powered off.

Like this?

Yep. But you honestly have to measure the resistance. There's no knowing if VW buried a terminator in the ECU or cluster.

Ok so with nothing connected to the leads ill measure on the ECU side and the cluster side separately.

If there is a terminator it should give a reading like this?

That is correct. If it reads open then it means you need a terminator there.

Excellent.
Ill give it a go.
It hasn't worked for me so I'm sure at least one end is open.

Are you trying to figure out if you can put the cluster and ECU in another vehicle for a TDI engine swap? Just curious.

I'm trying to adapt IMMO 3 keys on the bench.
I can do immo2 no problem but IMMO3 needs to see the IMMO-ID from the ECU over the canbus.

I'm hoping bridging a resistor across both ends of the can high/low wires will allow it to work.

I have been tinkering for months with this.

I did a quick test and found that the ECU has 120Ohms of resistance between the CAN HIGH and CAN LOW.

But the cluster is open circuit.

What are you guy talking about resistors.
You do not need any resistor .
All you need to do connect CAH-H and CAN -L between Cluster and ECU and OBD.
Run K-line form Cluster to OBD.
Then you have to connect W-Line to cluster form ECU .
Also you need to have Immo coil connected to cluster.

Also you need to have 12V and ground as well.

You do not need any resistor

Click to expand...

False:

The termination resistors on a cable should match the nominal impedance of the cable. ISO 11898 requires a cable with a nominal impedance of 120 ohms, and therefore 120 ohm resistors should be used for termination. If multiple devices are placed along the cable, only the devices on the ends of the cable need termination resistors. Figure 2 shows an example of how to terminate a high-speed network.

All you need to do connect CAH-H and CAN -L between Cluster and ECU and OBD.

Click to expand...

I'd say 99 out of 100 of our problems with CAN at work are based on resistor problems. Either the Techs don't include them or they see an open CAN port on the line and go "well this looks like a good place for a resistor". Current record is 10 terminating resistors in a single line.

jetta said:

What are you guy talking about resistors.
You do not need any resistor .
All you need to do connect CAH-H and CAN -L between Cluster and ECU and OBD.
Run K-line form Cluster to OBD.
Then you have to connect W-Line to cluster form ECU .
Also you need to have Immo coil connected to cluster.

Also you need to have 12V and ground as well.

Click to expand...

When running the CAN wires to/from the cluster

A-CAN HI/LOW (in) from ECU and then CAN HI/LOW (out) to OBD

OR

B- CAN HI/LOW (in) from ECU and use the same lines to to to OBD

darkscout said:

False:

The termination resistors on a cable should match the nominal impedance of the cable. ISO 11898 requires a cable with a nominal impedance of 120 ohms, and therefore 120 ohm resistors should be used for termination. If multiple devices are placed along the cable, only the devices on the ends of the cable need termination resistors. Figure 2 shows an example of how to terminate a high-speed network.

I'd say 99 out of 100 of our problems with CAN at work are based on resistor problems. Either the Techs don't include them or they see an open CAN port on the line and go "well this looks like a good place for a resistor". Current record is 10 terminating resistors in a single line.

Click to expand...

Please you are talking non sense, we are talking about 2 device ECU and Cluster on the bench table.
I have bench wiring harness made 4 years ago with out any resistor, and made over 100 adaptation cluster to ECU and ECu to cluster , match the keys and etc.
Look at this video , this was done with my wiring harness on the bench:
http://www.youtube.com/watch?v=lbeRRFop6Mc

Also I have done CCM windows mode on the bench many times , and never had any resistor.

So it is very simple:
You DO NOT NEED any resistor for bench tool .

floyd27 said:

When running the CAN wires to/from the cluster

A-CAN HI/LOW (in) from ECU and then CAN HI/LOW (out) to OBD

OR

B- CAN HI/LOW (in) from ECU and use the same lines to to to OBD

Click to expand...

I am not very good in drawing but I think it will help you.You will need to add 12V Terminal 15 and terminal 30 , and ground.
Gray wire is K-line.
Here :

You DO NOT NEED any resistor for bench tool.

Click to expand...

You're the one spouting nonsense. It's in the CAN/J1939 specification. It's DESIGNED to work like that. Perhaps you got lucky.

Before trying to trouble shoot why certain things don't work it's best to have a properly setup network. Just because it works for you doesn't mean that's the correct way

You can sometimes also cheat and put a 60 Ohm resistor across 2 devices making the resistance of the entire line 60 Ohm instead of using 2 - 120 Ohm resistors.

I'm familiar with plenty of other data networking standards that require terminators. It is not AT ALL unusual for them to "work" with a simple (ie 2 device) network while missing their terminators, but if there is any EMI noise or anything else in the area things go screwy. The standards include those resistors for a reason.

Yup, back in my day the Internet was called "10Base-2 coax cable to your big-ass mainframe" and would run kinda ok over short hops ifyou forgot the twist-on terminating resistors at the far ends, but all kinda weird ghosts-in-the-machine cropped up if the run had any length to it...or more than one tap.

Just like belly-flopping in a pool.,.reflections and constructive/destructive interference.

darkscout said:

You're the one spouting nonsense. It's in the CAN/J1939 specification. It's DESIGNED to work like that. Perhaps you got lucky.

Before trying to trouble shoot why certain things don't work it's best to have a properly setup network. Just because it works for you doesn't mean that's the correct way

You can sometimes also cheat and put a 60 Ohm resistor across 2 devices making the resistance of the entire line 60 Ohm instead of using 2 - 120 Ohm resistors.

Click to expand...

I guess you are not very familiar with VAG cars. Those resistors are built in the every module in VAG cars , and that way you do not need them in harness. I will give you $ 1000 if you find me resistor in any VAG car wiring harness.
That way when you have problem with CAN Bus in VAG cars it tells you first to measure resistance at CAN Bus pins in faulty module.
It looks like I have you draw it everything for you.
Picture can say 1000 words:

http://www.keil.com/forum/21024/

Those resistors are built in the every module in VAG cars

Click to expand...

If that's true then why did his ECM measure 120 Ohm and his cluster read open? The ECM has the terminator built in as it's designed as the last stop on the tracks. The cluster is not. It probably goes to the radio or something where there is a terminator there.

I will give you $ 1000 if you find me resistor in any VAG car wiring harness.

Click to expand...

I'll take that $1000. It's in your ECM. Just because the terminating resistor is built into a device doesn't mean that it doesn't exist. A lot of devices will have a jumper as to if you want them to have internal resistance or not.

darkscout said:

http://www.keil.com/forum/21024/



If that's true then why did his ECM measure 120 Ohm and his cluster read open? The ECM has the terminator built in as it's designed as the last stop on the tracks. The cluster is not. It probably goes to the radio or something where there is a terminator there.

Click to expand...

Probably he did not check it correct pins or his ECU is faulty.
For cluster He probably did not read correct pins in cluster.

In MK4 Golf/Jetta I did measure at my spare ECU and it has 62 Ohm between pin 6 and 7.
Cluster reads much more ( 2.4 KOhm) and this is because in VW Cluster is main unit with CAN Gateway module built in and where all CAN bus module goes through .
K-line Audi cluster is little different since there is not Can Gateway module built is cluster , but it is based on same technology.
MK5 Golf/Jetta also works different way and you need to have external Can Gateway module connected along with ECU and cluster.
And can talk about this for ever.
When I connect ECU and Cluster on bench and code cluster properly like all modules is there, Cluster will have faulty code for missing controller ( EX. ABS) but ECU will not have. That why cluster has different resistance.


One thing is OP never specified what car he is working on, and what year.

darkscout said:

I'll take that $1000. It's in your ECM. Just because the terminating resistor is built into a device doesn't mean that it doesn't exist. A lot of devices will have a jumper as to if you want them to have internal resistance or not.

Click to expand...

Like I said before you are not familiar with VAG cars .
The link you post above is just a basic info , But every Manufacture does different way.
Please read post above again. It tells you very CLEAR when you checking wiring you can not have any resistance between pin , this mean there is no resistor in wiring.
They are built in Each module.
MAYBE some other cars has , but not happening in VAG cars.

So reality is :
YOU DO NOT NEED ANY RESISTOR FOR BENCH TOOL IN VAG CARS.

Audi A4 2004 ME7.5 ECU-- 120ohms across canH and canL

2002 Passat VDO immo3 cluster.
Open across all combinations of CanH CanL
Both on the "in" and "out" lines.

By the way. I was not trying to pair those.
Just the closest ones I had next to me to test.
Both are 100% working functional parts.
The ECU is actually out of my own car.

floyd27 said:

Audi A4 2004 ME7.5 ECU-- 120ohms across canH and canL

2002 Passat VDO immo3 cluster.
Open across all combinations of CanH CanL
Both on the "in" and "out" lines.

Click to expand...

Audi ECU works different way.And you can not adopt VW cluster to Audi ECU regular way, you have to do it manually.
On cluster did you measure resistance between pin 19 and 20 on green connector?

I was not trying to pair the AUDI to the VW cluster.
Just has a Audi ECU and tested it.

I re-tested the clusters and as I dont have a auto ranging DVOM, when at the ohms scale it reads open. I switched it to K ohms and got the proper readings.
I was expecting 60-120 Ohms so I never though of changing the scale.
My fault there.


AUDI ME7.5 120 Ohms
VDO Passat IMMO3 Cluster 2.40K Ohms
VDO Golf IMMO2 cluster 2.39K Ohms
VDO Jetta/GLI IMMO3 cluster 2.39K ohms

All reading are with the OEM harness (cut off of course). Across the CAN-H and CAN-L lines