I took my Jetta 99' 2.0 Manual to get Smog Tested and their scanner did not communicate with my car. At the shop I tried unplugging the stereo because they said that might be the issue. Failed due to incomplete test. After I did a lot of research I discovered that it could be two common issues, first that it could be no voltage in the area. Some people advised to check the cigarette lighter fuse and other fuses with close approximation. The second advise was if you have an aftermarket stereo (not stock) to look for the K-Wire and cut it or make sure nothing is plugged into it. Unplugging the wires from the back of the stereo wasn't enough. You need to dig deep in and unplug the aftermarket wires. Gladly, the stereo was the issue. Thanks a lot for posting this video.
Yep, you would think that the radio installer would know not to tie onto the communication line unless the aftermarket radio has that option, and probably not one out there. Nice having the procedure in the description to show the procedure and glad it all worked on for you :)
Installers are under pressure to rush... I guess that's where the issue might be. Similar to flatrate techs, needing to take shortcuts to make time. Lots of great flatrate techs out there, but I couldn't do it.
I could never work at flatrate because I would be too slow and would starve to death. I went to a shop having my tires changed and was talking with one of the mechanics of where they are on flatrate. I asked him that if he didn't work on anything that day would he get a minimum wage. He said, "Nope, not a cent!" I told him, "no way in hell would I work under those conditions." And I feel pity for the young soul who goes to work that doesn't have any experience." Have a good one Thomas!
Cool never seen that before Thomas. I read a bulletin on a MK5 Golf that the central locking wouldn't work with the key off if it had an aftermarket radio. That was because the batt+ and ign+ wires were crossed in the ISO connector. Have you ever seen that?
Every time I brought my Passat in for a smog check back in California, the techs would freak out when they saw the aftermarket radio, and I'd have to soothe them with "Relax, no K-Line issues with this car." One guy still refused to smog it until I plugged in my scan tool in front of him and showed him there were no problems. If only people would read the instructions typically included with aftermarket radio harness adapters!
There was a time when we would not scan them either (late 90's)... then I got my ross-tech cable (that took my worry away). Certain customers we won't pull the radios... we let them deal with it (go back to the radio shop). "Ever since you removed my radio!!!"... don't want to deal with that! =)
this is good to know. ill fix mine when i get back to fixing the beetle i hop soon. thank goodness the bleeping wires werent cut and spliced in. my 1987 nissan pulsar nx does and instead of cutting more wire till i ran out of harness i put on male/female insulated blade connectors so just have to unplug it.
From the Ross-Tech link: "Nothing in the car cares if the K-line is shorted to +12. The K-Line is not used for intra-vehicle communications. But a scan-tool initializes a communications session by pulling the K-line to ground. The K-line is supposed to have some voltage on it, but through a high-impedance source. If the K-line has "hard" +12 on it, something has to give! What "gives" is usually the scan-tool's output driver for the K-line. And fixing a VAG-1551/1552 with a blown K-line driver is expen$ive! But the ISO-COM PCCar interface adapter that we provide with our VAG-COM software has a small user-replaceable fuse protecting the K-Line output driver, and there's a spare fuse taped under the lid of the little box. No big worries there..:-) Our other interfaces use output drivers that are thermally protected against shorts. They don't need a fuse. If you plug them into a car with the K-line shorted to +12, they simply won't work in that car, but it won't hurt them either."
So I have a question. I am now at Proud owner of a 2003 VW Beetle. It has 1.8 turbo AWV engine code. I cannot get my generic scan tool to communicate with my vehicle. There is no factory radio in this vehicle. Is a factory radio needed in order to communicate with the vehicle? I do have an aftermarket radio I can install professionally. Any suggestions or comments?
Preston Fore A radio is not needed for OBD communication. An improperly wired radio will however cause communication issues. If you don't currently have a radio in the car, make sure that there is no aftermarket wiring attached to the stock radio harness plugs (the brown & black plugs). Follow the instructions / info that is linked in the description.
Nice to find and see this video. We do have two Skoda Fabia combi Elegance make 1 year 2005. I tried to read fault codes at one of them, with my Vgate VS 450, and got a few link error in my screen. For example link error for Central locksystem and interior monitor. I thought the scanner was broken down, but plugged it to the other car. There everything is working, and i also could erase a code for central locking. The only difference between the cars is the radio. The link error car has a aftermarket one, the other a original one. I followed the video, an disconnected the wireharness at the aftermarket radio from the stock harness. But unsuccesful. Do i have to doe some more steps to get my Vgate connected again?
It affects the expensive scanners as well... it can actually fry the scan tools. VCDS has a safety built in... that's how it's able to show the red LED / Warning. All you need to know about the issue can be read here: www.ross-tech.com/vag-com/aftermarket-radio.html
Is that common on MK3's? I'm having issues with mine, I swapped in a black interior when I changed my heater core and installed the stereo last summer.
I have an Impala 2011, I am having trouble with ANY car audio harness I use. They are always generating false fault codes. I have taken it to 2 different local shops, and the dealer. PAC OS-5 caused intermittent stabilitrak errors, transmission control module errors and LAN communication issues. At one point it actually turned off all my gauges. No Tach, Speed, temp, or fuel gauges. I then switched to a Maestro RR. This one is generating the same stabilitrak fault codes as well. Between switching the car audio harnesses, I gave some time in between. About 1 month, when I had nothing connected to the dash. The factory harness plugs were completely disconnected. As soon as I plugged in the Maestro RR harness, the following day it generated stabilitrak fault code again. Ideas? Tips? Would be helpful thanks.
Not sure... I would have to look at a wiring diagram. A good radio / audio shop should be able to determine where the issue is (radio / wiring is interfering with vehicle electronics / communication issue).
Great video. This is currently happening to me. Fiat punto 2001, this morning, took the aftermarket radio out, light still red. I cannot take the radio fuse because this 10 amp fuse it is shared between radio and obd port. The thing is I cannot find the stock conector. Any ideas?
I can only suggest to keep looking. Other things besides radio can also cause communication issues. Rule out the radio / connectors first, then look for other possible issues.
@@EXOVCDS awesome, I will do look for another causes. But what should I start looking at? Just to get me starting on this task. Once again, thanks for taking of your time to reply. You're the man.
@@korbendallas9689 I would need to look at a wiring diagram to see how the communication wiring is spliced & how many modules the car has. Sometimes a bad module can cause communication issues with the system... disconnecting one module at a time, can help determine if a module is at fault. Using a scope to view communication signal attempt, can also help guide you in the right direction... but not everyone has a scope. The radio issue is more common on VWs. I have no experience with Fiat, sorry.
I just bought a new harness for aftermarket radio and it comes without that wire in the harness. Surprised they removed it. I guess they know of the problem. Anyways now I can scan car without removing the radio
04 GLI with an aftermarket radio and 12v between pins 4 and 7 on the obd connector. I can't understand the graph rosstech has on their website my radio harness doesn't look like the one they show so I can't figure how to fix it
You will have to use a stock wiring diagram for the factory radio... to see / compare how the aftermarket radio is wired into the factory wiring. Then, eliminate the wire that is causing the issue.
I completely disconnected the radio, and it did not change anything. Still can’t read engine or abs/brake codes. Suggestion on next step to take? Already checked fuses / fuse boxes.
1999 Audi A4 B5 1.6 gasoline. Problem is still there. I disconnected that connector and nothing, still can't connect to vehicle ECU. And that 3 pin wire is constant power to my radio, it should be like that ? Also I check voltage between 4 and 7 pins in OBD II port and it shows 11 V so it should be problem with K-line. Also I use OBDII elm327 mini bluetooth scanner (branded), not the best tool but I wanted try it before buying normal VAG K+CAN, I would be very appreciated to any help.
If there are no other aftermarket items in the vehicle that were possibly wired incorrectly, then it is one of the modules in the vehicle that could be causing the issue. Check the comfort control module for wetness (under the carpet), the ABS module is also a common item that can cause no comm. Disconnect one module at a time until you get communication back. I can look for a wiring diagram for your vehicle after I get home from work later tonight.
I had the same issue after installing a new radio, the harness has a cable that goes back to other pin. I chopped the crap out of that little cable and voila!
I am having similiar problems. I just found this videos. thanks a lot. My car does have an aftermarket radio... Before I dismantle it ill try by removing the fuse first .....
Thomas EXOVCDS never mind man. Should have paid better attention to my wiring diagram. Obd port is in the same circuit with the radio LOL. Suzuki Jimny 2003.
Thomas EXOVCDS removed the radio. It wasnt enough to get the obd port talking. I found a mess. I bought the car from a friend. The radio wiring seems altered. It’ll take me some time leaving the wiring back to stock. I’ll update then
Could you just remove terminal 7 out of the OBD port and by pulling the k-line fix the issue? My Jetta has no radio but I’m still getting the k-line fault preventing the OBD from communicating.
Perfect time for you to make a video about it! =) The closest I have come to make a video about is... is THIS video. The more information I have, the better I "might" be able to help. What engine? What Transmission? Power windows / Door locks? Aftermarket radio? What scan tool are you using? Can your scan tool communicate with OTHER modules (in your car). If not, get a different scan tool, so you can check (if it's a scan tool issue).
what is the color of k-line wire you removed from radio connector im having same problem with my 03 silverado ls someone put an aftermarket radio and obd 2 keeps giving linking error any help will be appreciated thank you...
I don't know if the Silverado radio is a "smart" radio (has diagnostic capabilities / communicates with other modules). The wiring colors are most likely different anyways.
I recently got a Aftermarket Radio & Speakers installed in my 08 VW R32. After they installed everything and the backup cam. My airbag light is on. ABS light is on, Traction Control Light is on and I plugged my ob2 in and im getting TCM Communication Circuit Range/Performance & Lost Communication with ECM/PCM A. Any ideas how this may have happened? Any help would be great.
Something with the network communication wires for the radio is causing lack of communication with the network... you probably need to install an interface box, to reestablish communication amongst the network. Something link this: catalog.pac-audio.com/catalog/radio-replacement/c2r-vw2 Contact the manufacturer and explain your situation to see what they recommend (the above link is just a sample... I don't know if that's the one you need). pac-audio.com/contact/
Yes sir, plus it's the almost impossible government emission control standard that drives a lot of it (I'm thinking). We do get great performance from our cars when there right though.
I removed the blue wire and pin from the aftermarket plug. But when I reinsert the factory’s plug the scan tool won’t read still. But if I disconnect the wire harness the scan tool reads ? What is the problem now ?
One of the other wires then... if you can't find the wire that is causing the issues, just scan with the radio disconnected. I have a few customers with similar issues... they don't want to pay me to find the problem, they just want me to disconnect the radio every time I need to scan the car.
I have a 99 cabrio and about to install after market radio I read link but still confused on how to test with volt meter. Do I put meter in the 5 and 6 spots or 4 and 7? Also which wire do I remove from harnness and is wire removed from stock plug or aftermarket plug?
I can not explain it better than what is mentioned in the ross-tech link. Simply follow those instructions. It doesn't matter which side of the connector the wire is disconnected... the #3 wire in the black connector (as mentioned in the link).
Hi EXOVCDS, my car did the same thing (seat ibiza 6k2 cupra 2000), when i plug the scan tool the light is red like in your video. I don't have an aftermarket radio, but i think it use to have one since i found some aftermarket harnesses on stock 8 pin black. I did remove that harness but still the same issues. I did cut as well the location 3 wire from the stock 8 pin black, but not working. And i see that i have only 3 wires connected on my obd2 port. Could you help me please?
Not sure... remove the K-Line pin at the DLC / Diagnostic Link Connector (do not cut the wire) and see if you now get communication. Your vehicle might be using CAN-Bus to communicate, rather than K-Line. If you still have communication problem with the K-Line removed, then there is a CAN-Bus communication problem... possibly a problem with one of the modules in the vehicle or a wiring issue. Some reading material: www.ross-tech.com/vag-com/aftermarket-radio.html www.volkspage.net/technik/ssp/ssp/SSP_238.pdf
I have 3 vcds scan tools that works other cars. hex-net hex-can and micro-can. I have got a passat b5.5 and none of them are communicating or it says gateway not supported and it wont scan. and the car has stock radio. I even tried a cheap streetwize scan tool that powers up but still fails to check. before I dig into whats causing the problem is there ways of checking up?
Does the car run? Won't connect to ECM, ABS, TCM... or nothing? You need to check the DLC connector www.ross-tech.com/vag-com/images/DLC.png for correct power & ground, as well as the other pins for correct voltage signals (square waves)... ideally with a scope (so you can see disturbances). ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-uKnQI2IScPU.html
@@EXOVCDS yes the car runs and drives but has reduced power. nothing seems to stand out and I cant see any problem and the engine still purrs nicely like nothing happened. Ill have a look. thank you.
@@EXOVCDS I tested the ecu by inserting pieces of wires into the back of the ecu pins and connected the other ends to the scan tool and it worked I also bought a bunch of wiring loom of a parts car and replaced it the wiring loom on this car was all hacked, soldered, taped and chewed I don't know what previous owners were at and it'll take forever to figure out. and with the new wiring they all came with pins attached but the car was butchered to get all that out. I copied all the wires with original. and I soldered some onto it. it works. I thought it may need an ecu and cluster and transponder. took me a while to do it, it was a nightmare. previously I checked fuses and back radio and pulled out all the engine connectors and modules etc thank you very much for help I enjoy all of your videos.
@@bencrosbie Thank you for the update! Wow... good investigating & repair work! I'm sure it will start to run better once the ECM gets all the correct signals / information (and viewing scan tool info will help you as well)!
I need help big time, so please respond anyone if you may. I’ve been messing with my oem radio on my 2005 Audi s4 b6 and it’s come down to where I know I have several fault codes in my radio, but vcds can not communicate with the radio. What has been done is an aux cord has been added to the original Audi wiring harness plug. So if you understand my troubles, please help me. Thank you.
Hey Thomas I'm having the same issue, I used to be able to scan car no problem with a cheap scanner and my vcds and now I can't. Any help would be appreciated. 04 Jetta TDI 1.9 bew -thanks in advance
Aftermarket radio? Did you check the wiring as per information in the description? Did you check if any of the pins in the data link connector are pushed back (do not make contact with the scan tool connector)?
@@EXOVCDS yes aftermarket radio, I tried to find the pin like it said in the description link but to no avail I couldn't find it. It will connect but only while the car is off. I used to be able to connect using vcds while car was running.
Have you done a full system scan with vcds? Maybe there's a module that's causing issues once the engine is running. If you get any "no communication" faults from certain modules, disconnect those modules and see if you can then communicate while the engine is running.
With the key in the ON position... is the "check engine light" ON (it should be)? Yes / no? There's no 109 relay... but there is a 428 relay. Next to the brake fluid reservoir, there's a plastic square / rectangular box. Remove the lid and you should see a relay marked 428. No need to check the relay if the check engine light IS on.
Hi i own a Audi A3 1998 and having problem with Reading the obd2 port i have tried with 5 different readers and all they say is that the protocol was not found. I have a aftermarket stereo installed just like you. But when i inserted a 1K ohm resistor into pin 4 and 7 it dosent get hot. Dont really know what to Think of it.
I just needed to know if it starts or not... if it didn't, then I would have suggested that the ECM was not getting power. I'd still start off with disconnecting the aftermarket radio (also remove any wiring harness connectors from the stock plugs, if there are any) to see what happens.
Love your work fella ... I bought a second hand Caddy which had the flashest of flashes stereos in to my horror when I had to pull the fascia out let's just say people who do that thing do a wire harness need their fingers cut off as there is linked adaptors for most radios is there not ? I take some reassuring given your working on volkswagen's that losing 10 minutes was a problem take this time and put a big fuck you shout out to Volkswagen as they deliberately make it fucking hard to extract any info
Not VW's fault if someone installs a radio incorrectly. If the manufacturer of the adapter doesn't make the public aware of a possible communication issue... 90% of installers will not worry about it / check OBD for communication after installing an aftermarket radio.
@@EXOVCDS yes its beyond belief .... my gripe with vw is they make it more than obvious that they drag their feet and are a deliberate hindrance in releasing or giving you any information to help ....not what you would normally expect if you were a customer of the parent company I find this to be quite disgusting... I can't be the only one who's noticed this attitude ?
Sorry I didn't get a notification for your last reply. I'll have a look for a diagram tomorrow. Don't know if I will find one... we don't have Caddy's in North America.