no start electrical symptoms: diagnosis?

Schlepper

Active member
Joined
Feb 16, 2013
Location
Grand island, florida
TDI
2005 Jetta MkV/A5 TDI
I have searched thru the threads, and seem to go in circles. Here is the car, the symptoms and would appreciate any direction on accurate diagnosis:

2005 Jetta TDI (new Jetta) bought new in 2005 for high school aged son who drove it for 12 years
Bought back from him last year with electrical issues as follows:
1. battery won't stay charged; dies overnight-had to be jumped to start
2. now, it will not crank when turning key and cannot move shifter out of Park (I removed the starter solenoid wire and jumped it with trigger switch and it does turnover/crank, just does not start; also, while turning key, electrical dash does come on and the amber icon of a steering wheel is what remains on along with a bulb showing out (but don't see a bulb burned out?)
3. a/c has not worked for awhile (may be unrelated) but radio does come on
4. drivers door has at least 1 wire that is severed
5. when I remove the positive side of battery terminal, there is a good deal of sparking both on removal and on placing it back on the battery (assuming this means I have a ground short somewhere but don't have a clue where to start with this)..

Prior to the full blown inability to start from the key switch, I could jump it with a battery booster and it ran great (has the rivet failure looming in the dry clutch which needs to be replaced but is unrelated to electrical issue). The sounds from under the hood when you turn key on (assuming an electrical fuel pump) sounds now do not come on.

My questions:
a. does this sound like a 109 Relay failure?
b. does this sound like a key switch failure?
c. does this sound like a ECU failure? (where is the ECU on these models?)

I've worked on old cars, carburetor inboard v-8 gas boat engines, my sailboat's inboard Perkins diesel engine and am of decent mechanical capability but I am not good with electrical issues... need help as wife wants to junk it, I want to make it a daily driver!

Thanks,
Schlepper

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relumalutan

Veteran Member
Joined
Dec 6, 2012
Location
Michigan
TDI
06 Jetta TDI Special Edition
Just my thought, as I have been dealing with this type of nightmare:

1. I would replace the driver door harness and clean (not just inspect) all the grounds in the engine bay. Note that you need to remove the battery and the battery tray to access one of the important grounds.

2. I believe that due to the repeated complete electric drains the battery is toast. When that happened to me, I could not get it to crank, even with jump-starter cables. The yellow steering wheel warning always comes up after the battery is being disconnected or as in your case, dies overnight. Once you start the engine and you drive for a few seconds, it will go away. Same with the auto down/up function of the windows, you need to re-set it (see # 4).

3. AC might not be working most likely due to a failed RCV valve. Are the fans coming on within 20-30 seconds after you turn on the AC? This issue might be also caused by a toast cooling fan. And lastly, this might be caused by a weird electrical issue, as in my case: my car has the winter package, meaning it has heated windshield wiper nozzles. As you sitting in front of the car, facing the engine bay, you will see on the passenger side a black harness going into the hood of the car. That harness is too short, and over time some of the 4 electrical wires will break, causing a electric shortcut and causing AC to not work (G65 pressure sensor short to plus error in VCDS) . I would undo the electrical insulation on that harness and check for broken wires, as that might also be the culprit for your overnight battery drain. Fixing the broken wires solved my AC problem.I see you're in Florida, you might not have that package.

4 See #1. Also, this is just a guess: sometimes due to aging and daily wear and tear, the window power motor module (looks like this: https://www.ebay.com/p/2005-VW-Jett...wer-Window-Motor-Module-1K5837402H/1023944680) gets tired. That's why once in a while the windows auto up-down feature will not work, and you have to re-set it by doing a few up-down cycles while keeping pressed the window switch. My battery drained overnight when that happened (I have the auto window up feature when I lock the car from the key-fob, sometimes one of the windows fails to go up when I lock the car). It might be a coincidence, I don't know.
 
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Schlepper

Active member
Joined
Feb 16, 2013
Location
Grand island, florida
TDI
2005 Jetta MkV/A5 TDI
ECU on 2005.5 Jetta TDI

Do you know where the ECU is and is there a way to test it to see if that is the problem? What I wouldn't give to go back to just a plain vanilla turbodiesel without all the electronics.
 

Schlepper

Active member
Joined
Feb 16, 2013
Location
Grand island, florida
TDI
2005 Jetta MkV/A5 TDI
I have taken the dash partially apart and dropped the Relays behind the dash out and ran a test on them. All have zero Ohms when the electromagnet is energized... so they appear to be working. I did the same test on the three electromagnetic relays under the hood and get about .3 Ohms resistance on all three Relays. I am not getting a Glow Plug or Engine Light on at the turn of the key... getting frustrated. Thoughts on the issue here? Transmission shifter still stuck in Park, it won't move still.
 

Schlepper

Active member
Joined
Feb 16, 2013
Location
Grand island, florida
TDI
2005 Jetta MkV/A5 TDI
My plight continues. I got the battery out, topped it off, got it back in the car, pulled off the solenoid on the starter, put the remote trigger switch on it and hooked to the battery and initially got nothing but some sparking... then the starter kicked in and the engine turned over. I had the key switch on... it didn't start. perhaps someone had to be in the cabin with foot on brake, I don't know. I checked all of the fuses, I pulled the relays under the hood and the drop down relays, they seemed to check out when I put electricity to the small tabs.. the Ohms went to zero... I don't know what else to do with this thing... it was once a great car. I guess this will be the last VW I ever own....the Duramax becomes my daily driver now...Regardless, I'm about ready to call the wrecker to tow it to the junkyard. Only 119,215 miles on it, what a shame.
 

Schlepper

Active member
Joined
Feb 16, 2013
Location
Grand island, florida
TDI
2005 Jetta MkV/A5 TDI
i decided to give it one more try today... it's not easy to find the relay diagrams, etc. so having to just check everything. All of the relays underneath the dash appear to be working ok. I am at a loss as to what the heck the problem is. Not able to shift out of Park (AT), and none of the engine electrical symbols pop up on the instrument cluster at the turn of the key... Totally flummoxed. This just should not be this difficult.
 

Schlepper

Active member
Joined
Feb 16, 2013
Location
Grand island, florida
TDI
2005 Jetta MkV/A5 TDI
I took the positive lead off the battery, and the negative lead and touched them together for 2 minutes. I took off all of the relays and tested them for off/on with the application of power and then did another test on the voltage flowing thru the large tabs with the switch being 'on' simultaneously. All checked out. I'm not electricity expert, but it would seem that if 12.85 volts are flowing thru the circuit, then the contact is good. The Ohms were at 0.0 as well when the Ohm test was done with the switch 'on'. I tested the relays in the engine compartment box and they appeared to be good too. In searching thru these threads on this site, I've not found where anyone solved the problem that I have on an A5 Jetta or Golf. All recommendations are to fire the codes thru a diagnostic tool but never hear of a 'fix' that is successful. The other recommendations are to check the ground straps and wires. I pulled and cleaned three grounds on the chassis in 2 places and on the transmission. They didn't appear corroded but I cleaned them to a shine.

So I will put the question out there: Has anyone had the following symptoms that they have successfully resolved on an A5(?):
- AT will not shift out of Park
-Engine electrical circuit not getting power (glow plugs, starter circuit, electric fuel lift pump, etc.)
-right from marker light will not stay working...
-battery constantly drains

I'm sure there are other issues, but those are what I'm seeing right now... anyone ever solve these problems? I see plenty that have experienced same but not seeing them successfully resolved... .if so, what solved the problems?
-
 

sptsailing

Veteran Member
Joined
Jul 9, 2010
Location
Safety Harbor, FL
TDI
2006 Jetta Manual, stock with Panzer Plate & Franko6 modified EGR cooler & CAM
My A5 Jetta is a manual, which of course cannot be started unless the clutch is depressed. I suspect an automatic cannot be shifted into gear unless the brake is depressed, with a sensor of some sort checking the status. A good read on the electrical system can be downloaded from one of these two links:

http://www.vaglinks.com/vaglinks_com/docs/ssp/VWUSA.COM_SSP_873403_MK5_Jetta_Electrical_System.pdf

https://mafiadoc.com/vwusacom-vw-mk...troduction-ssp-_598030311723ddf056a7ce2c.html

Since the car is so dependent on electronics, the battery will always have at least a small load, if for nothing else, to make the blinking door lock lights, so the question is, how much is the drain. The ammeter function of a multimeter can measure that. My car was shipped to the buyer with a solar panel just for that reason.

Years ago, I concluded that a VCDS was a necessity if I was going to own this car, as it is required to find out what the car's systems will tell you.

In my opinion, although these can be frustrating cars, they are well worth spending the time and usually worth the money to keep them running.
 

Schlepper

Active member
Joined
Feb 16, 2013
Location
Grand island, florida
TDI
2005 Jetta MkV/A5 TDI
Sptsailing... thank you for the response and the information. I had a 2005 Passat that I drove for about 7 years while our son drove the 2005 Jetta that is the subject of my frustration. I traded the Passat on a 2013 SPortwagen that was a fantastic vehicle and I never had any issues with it before selling it back to VW as part of the 'scandal'. I wish now that I had kept it.

I'll look into the links you attached.

I see 'sailing' in your handle... and you're in Safety Harbor. Do you sail in Tampa Bay or over in Clearwater? I keep an old Morgan down in Palmetto...but live North of Orlando which I want to keep this 40 mpg vehicle for my commutes to the boat! I need to figure it out.
 

sptsailing

Veteran Member
Joined
Jul 9, 2010
Location
Safety Harbor, FL
TDI
2006 Jetta Manual, stock with Panzer Plate & Franko6 modified EGR cooler & CAM
I'm a trailer sailor, although my Bay Hen hasn't been wet for over a year due to aging parent issues, other family issues and car repairs. So far this year I have done 3 timing belt jobs, 2 wheel bearing jobs, 1 cam job, 4 cv axles and 2 all round brakes and rotor jobs. I have sailed the West coast of central FL between Cedar Key and Cayo Costa State Park, but usually just St. Joseph Sound and around Anclote Key. The boat needs some paint on the few wood parts.

I have found it to be a general rule that sailboat owner/sailors tend to be high IQ individuals, so I am fairly certain that if you decide to, you will be able to solve the problems with your TDI, but as I previously mentioned, using a VCDS is vital.

The links I posted are two different repositories of a single PDF file named: "VWUSA.COM_SSP_873403_MK5_Jetta_Electrical_System.pdf"

This is a training document for VW technicians that outlines how the electrical system in an A5 Jetta works. Others on this board and I have found it to be helpful.

Among many others, I have found the numerous posts by Franko6 and Oilhammer to be quite useful and reliable. Oilhammer has a lot to contribute regarding electrical problems.
 

Schlepper

Active member
Joined
Feb 16, 2013
Location
Grand island, florida
TDI
2005 Jetta MkV/A5 TDI
sptsailor,
Sorry to hear about the aging parent issues... We haven't done much sailing this year between weather, some mechanical issues (boat has the old Perkins 4-108 in it and it has had a few issues with IP.. but simple to solve relative to the TDI electronic mayhem!).
I downloaded the documents and read thru them. They do help from the standpoint that it clearly shows the interconnectedness of everything. I had no idea it was that involved. I seem to be having four main issues that may or may not be interconnected: 1.) the shifter won't go out of Park (now I see that might be caused by a brake/shifter solenoid being bad and I can hopefully resolve that) 2.) I don't seem to be getting electrical power to the engine bay, at least not strong enough to energize the starter solenoid (a voltage test revealed about 3.5 volts is all that was getting there from the key switch when tested with multimeter), 3.) the a/c has not worked in awhile (i see from this document that could be interconnected with a chronic state of battery discharge in a shut down mode), 4.) parasitic battery draw that is keeping the battery discharged... oh, and the bonus problems 5.) at least one wire to drivers door is severed... and 6.) I cannot keep a light bulb working in the passenger side front marker light...
#3, #4 and #6 have been prevalent since before my son sold the car back to me; the car was at least able to start with a booster at that time. Since then, it has developed #1 & #2... I just need to get the diagnostic tool or have someone with one diagnose so I can sort it out and know for sure what's causing these problems and then fix them.
Once I get all of that resolved, I have a DSG dual mass flywheel that needs to be replaced before catastrophic failure results... and on the aesthetics side of things, i have a droopy headliner...

Other than that.... it has great potential to be a 'cheap' daily driver as it only has 119k miles on it and it's a 13 year old car.

BTW, the sailboat we have is near constant maintenance, either varnishing teak, mechanical repair/preventative maintenance, plumbing/toilet/holding tank, packing nut for rudder and prop shafts, etc. but it's a labor of love. Once I figure out more of what/how to go about it with this VW, I think I can get it back to square.

Thanks again for the help... and direction. Good luck with your challenges...
 

Ol'Rattler

Top Post Dawg
Joined
Jul 3, 2007
Location
PNA
TDI
2006 BRM Jetta
Did you remove the airbox and clean and tighten the major chassis/steering ground that is hidden underneath the airbox? It is a known problem on the A5's. Once you have the airbox removed, look for an acorn nut securing 2 somewhat large wires to the chassis.

The best fix for the drivers door is to replace the harness. Trying to fix your door harness is problematic and ends up usually being a temporary fix. The early A5 door harness was made slightly to short and was upgraded in production in I think 6/2006 to be slightly longer.

After you fix the door harness, check out this TSB for diagnosing parasitic battery drain if you still have battery issues.
http://pics.tdiclub.com/data/500/TSB_27_08_04_Matrix.pdf
 

Schlepper

Active member
Joined
Feb 16, 2013
Location
Grand island, florida
TDI
2005 Jetta MkV/A5 TDI
Ol'Rattler, thank you for the response... I did remove, clean and retightened the 4 ground connections on the drivers side in the engine compartment... didn't help. I did get the car in neutral this evening so I can at least move it to the garage now to work on it.
Right now I am just trying to get power to the starter and the fuel pump so it will start... i just don't know what could be causing the problem... it gets power everywhere except full voltage to starter and to run the engine.
 

Schlepper

Active member
Joined
Feb 16, 2013
Location
Grand island, florida
TDI
2005 Jetta MkV/A5 TDI
Ok, I have a theory that I think may resolve my no crank/no start issue...

Symptoms:
1.) the shifter won't go out of Park (now I see that might be caused by a brake/shifter solenoid being bad and I can hopefully resolve that)
2.) I don't seem to be getting electrical power to the engine bay, at least not strong enough to energize the starter solenoid (a voltage test revealed about 3.5 volts is all that was getting there from the key switch when tested with multimeter),
3.) the a/c has not worked in awhile (i see from this document that could be interconnected with a chronic state of battery discharge in a shut down mode),
4.) parasitic battery draw that is keeping the battery discharged... oh, and the bonus problems
5.) at least one wire to drivers door is severed... and
6.) I cannot keep a light bulb working in the passenger side front marker light...
#3, #4 and #6 have been prevalent since before my son sold the car back to me; the car was at least able to start with a booster at that time. Since then, it has developed #1 & #2...

I have formed the theory that the brake light switch is the issue. Why? Because you have to press the brake pedal to:
1.) start the engine
2.) put transmission in gear

It may not resolve the parasitic drain, and it may not fix the front right marker light issue, but I suspect it will at least get the car running. Hopefully I can get a test of that theory early tomorrow morning... I will be ecstatic if that proves to be the case. I think the parasitic drain may well be the alternator... but first things first... get it running, then go for the rest...
 

Ol'Rattler

Top Post Dawg
Joined
Jul 3, 2007
Location
PNA
TDI
2006 BRM Jetta
Did you remove the air cleaner box and check the ground underneath it? That ground has 2 wires on it. One Wire about the size of a pencil and is pink that grounds for the electric steering and a much bigger black wire that is a major chassis ground and can cause many electrical problems like you are having if is not clean and tight.

Those 2 ground wires are bolted to the chassis rail by an acorn nut that is just like the acorn nut that bolts the battery ground cable to the chassis.
Put your remote starter switch away. It is of no use in troubleshooting your problem. If your ECU is not getting power or is not grounded well, the ECU can't send trigger power to the starter to energize it.

Also, next to the battery, there is a fuse box that have several red wires on the front of it. Between the 2 nuts on each wire are fusable link type fuses.

 

Schlepper

Active member
Joined
Feb 16, 2013
Location
Grand island, florida
TDI
2005 Jetta MkV/A5 TDI
Ol Rattler,
Yes, I did get all the grounds on that side removed and cleaned... there are 4 contact points I could find.... the battery negative cable, the ground from chassis to the transaxle, and the 2 wire ground just behind the driver's side headlight assembly... those have all been removed, cleaned and retightened. I will doublecheck all for tightness, but am certain that is all ok... Thank you for your input, it is greatly appreciated.
 

Schlepper

Active member
Joined
Feb 16, 2013
Location
Grand island, florida
TDI
2005 Jetta MkV/A5 TDI
I posted this over on the MkV page but I should also put the same info here. I finally found a site that lists every relay and every fuse and what it goes to for each iteration of the MkV Jetta.... the link is here: https://www.autogenius.info/volkswagen-jetta-2003-2009-fuse-box-diagram/

I put all of this on an excel spreadsheet and then went methodically thru every single fuse and placed the correct fuse amperage in the correct slot, etc. That got me back to being able to start the vehicle, which I'm almost 2 years from having it running last.

Now, the battery drained over night, so I'm back to trying to track down that original problem, finding the culprit to the draining. Now, armed with the spreadsheet I am much better prepared to find this problem and resolve it. Since posting this, I retired at the end of 2018 and have my workshop in better stead to work on things thus finally able to get to this and tackling it.
 
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