CAN-BUS Resistance on DLC 14 + 6 for early 2001 Jetta 1,9l TDI -

Uli Owner/Technician Ontario Posted   Latest  
Unsolved
Driveability
2001 Volkswagen Jetta TDI 1.9L (ALH) 5-spd (02J) — 3VWSP69MX1M216642
P1650
Intermittend Abs Traction
Airbag Light Comes On
Sometimes A No Start Due Flashing Immobilizer

Dear Friends:

this ( build May 2001) Jetta has no Gateway and apparently, to Alldata, the DLC connector 14 + 6 go to: Instrument cluster “Data Bus on Board Diagnostic Interface” if I measure resistance between 14 + 6 it reads ‘OL’. Okay, on a late model car I would expect 60ohm! Before I go on a wild goose chase, does anybody know what the reading should be.

The VW descriptions tells me: ..….. enables data to be exchanged between the vehicle CAN Data-Bus network and the Data Link Connector (DLC) “K-wire”.

Does this early car ONLY run over Pin 7 “K-Line”? Even it shows all the “orange+???” Data wires in the diagram.

Long story short: Does anyone have an old Jetta TDi in the shop and can measure pin 14 + 6 for me?

Thanks in advance,

Uli

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Obie Technician
Washington
Obie
   

If you can go to Ross-tech. They have good description about that system. Also ABS is a problem. Is it better when ABS is disconnected? Also, IIRC the cluster is the gateway. I know that aftermarket radios are a problem and take down a K line. That did not affect any other system. Check with a scope and look for anamolies. If you see them disconnect controllers one at a time. Also check under…

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Bob Engineer
Michigan
Bob
 

Hi Uli, Sorry, it is hard to tell what your real problem is from the description. Probably why Obie threw a number of unrelated items at you at the same time. I'll take a stab at decoding and also addressing the other items. Obie is partially correct. There is a K-line to CAN gateway that is located in the cluster. If I recall correctly your P-code is related to a gateway failure. I'd look…

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Robert Diagnostician
Qatar
Robert
 

A know good terminating resistance reading would be 60 Ohms on pin 14+6 at the (DLC) connector If a 120 Ohms is what you read in multimeter that means you have a break in the line between the two parallel resistor For what i understand in “OL” Reading on a multimeter is Over limit

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Bill Owner/Technician
Michigan
Bill
 

6&14 go directly to the gateway on this vehicle your resistance test is not valid on this design…. Pin 7 K line is your communication line.

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Bob Engineer
Michigan
Bob
 

I'm fairly certain that you are correct. Pins 14 and 6 are not a CAN bus, but other control signals to the gateway. Therefore, your standard CAN termination values are not valid here. CAN is only an internal bus on these vehicles, which is why they need a K-line to CAN gateway. My bet is still the gateway or the associated wiring/connector based on the P1650 code.

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Robert Technician
Michigan
Robert
 

01 has CAN H I'll take your word for it , all I have is an 03 true K line is a scanner comm and low speed bus signal for like a radio and accessories but a 1 wire scanner comm line probably close to 5v…CAN H sounds shorted does 6 2.3-3.5v & 14 1.5-2.5v.. CAN H probably goes to every module except a 1 or 2 … Thinkin this is classis battery disconnected and disconnect modules until &…

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Caleb Diagnostician
Indiana
Caleb
 

As Bill stated not a valid test. On my experience with VAG if there is no separate gateway module then the gateway is whoever the module is that is connected to the DLC. I'm this case the IPC. I had a 14 Bentley Continental the other day that the IPC was the gateway. It did not have separate gateway. If you put a scope on pins 6&14 they should 2.5 volt bias with car running/terminal 15 on…

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Uli Owner/Technician
Ontario
Uli
 

Dear Friends: Thanks to all which took the time to respond. I am sorry my question, got everyone confused. The main question was: What is the resistance value on an early Jetta if you put an ohm meter into pins 14 + 6? I have the Ross Tech HEX-CAN with the VAG-Saver (green/red LED), K line is fine! The customer complain was/is: 95% of the time car starts and drives fine. But…

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Bob Engineer
Michigan
Bob
   

OK, Uli, here's what I see. K-line is fine = no issue with ABS module or aftermarket stereo. There never was a real issue with ABS modules on Jetta from that era anyway. Only A4/A6/A8/Passat. Sometimes Google is not your friend. P1650 is related to failed gateway communication. The gateway is in the instrument cluster. It follows that intermittent warning lamps and “hitting the dash” could show…

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Robert Technician
Michigan
Robert
   

ABS Chassis will be on CAN High Homie says its not CAN please El German0 Boshski .. same system VW used 01 -05 or somesing …. K line is slow stuff like HVAC controls and Radio and limited modules on K line .Im not repeating meself …Yes I could be wrong but Im not diving into SI for some 01 VW Fox. Idoes agree with Bob on that Gateway part he said i think i did the once through …back out to…

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Bob Engineer
Michigan
Bob
   

Hi Caleb, Unfortunately 2008 and beyond vehicles have a completely different architecture than 2001s. 6 and 14 are required to be the legislated OBD CAN communication bus on newer vehicles. No such requirement on earlier cars. Those pins can be anything the OEM wants them to be. On this Jetta they are most likely control signals for the gateway. Cheers, Bob

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Robert Technician
Michigan
Robert
   

I guarantee you … is CAN High on 6/14 and can be Ohm battery disconnected ,my 1st VW was a 1977 Sciracco

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