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CCM replaced but still no start

5K views 14 replies 6 participants last post by  mrau92me 
#1 ·
I have 2000 1.8T Passat. My son started the car one day, shut it off to clean snow from car and got back in and car did not start. Didnt even turn over. Took into shop and they found the CCM burnt up. Quoted $800 for new module and reprogramming. Well I decided to try myself. Got a new CCM with same part number as previous one. Hooked it up and everything I think the CCM controls works fine. And key fob works everything as well. Ran VAG-COM for any faults and none were found. But unfortunately the car still does not start or even turn over. I can pop the clutch to start and drives fine. But as soon as I shut it off, no crank at all. Nothing. The shop said starter was OK. I did find a fuel leak in rear passenger side, but dont think that would cause car not to even crank. Anyway, I know it might just be the inspection of all the wires coming out of the CCM, but does anyone know which wire could cause no crank that might narrow down my search. No water ever got into the CCM and that area is completely dry and all wires seem to be pristine.

I did have the sunroof drain into the passenger side, so not sure if checking the module on that side (TCM) would be useful as again not sure if that would cause a no start. No faults or issue with gear faults.

Any help would be appreciated before I start inspecting each and every wire.
 
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#2 ·
Just to add to my post. This is a 5-speed. Also, just to rule out the battery, although it was only 8 months old, I took it to where I purchased it and they said it was low, but replaced with new battery. but this did not help my situation. Still no crank at all. Should I go back and relook at the starter, solenoid or maybe ignition switch? Clutch?

Thanks.
 
#3 ·
There are two interlock relays in the circuit from the key to the starter. One is controlled by the clutch safety switch so the starter will only run if you have the clutch pedal pressed. The other is controlled by the alarm system in the CCM. That one keeps the starter from running if the alarm isn't satisfied. Since you had a burnt up CCM, my first thought is a CCM related problem. Check every fuse (with a meter or test light). I think it's fuse #14 for power to the CM that controls the starter interlock.

Tomvw wrote a great post about diagnosing a no-crank situation. http://www.passatworld.com/forums/b...y-not-cranking-comprehensive-diagnostics.html
 
#4 ·
Great, I will look at No crank article.

Checked all the fuses and even replaced #14 with a new fuse just in case. Last summer, I did repair the door lock module after resoldering the broken solder joint. That was a no-start situation too but that one involved the key fob not working, alarm going off and of course not starting. But no similar issue with alarm or key fob now. But I may go that route and recheck that again.

The shop who originally diagnosed the bad CCM found it due to the strong smell of electrical burn. So I opened the CCM and found the board toasted. So wondering if there is an exposed wire from CCM that may have caused a shorting condition. That is why I am curious as to which wire might be related to a no-start situation. I dont know much about wiring so a schematic might not help me much. Like I mentioned, I have replaced the CCM with a new one and all the doors, windows, latches, sunroof and key fob all work fine. Although one other tidbit, they all also worked with the burnt up CCM. So that was very strange. Would that lead you to believe it is more related to the other things you said to check such as switches and relays or even going back to check starter and solenoid.

I will look into your suggestions and let you know how I made out.

Thanks again.
 
#5 ·
When our cars experience water ingress, often the CCM, TCM and/or wiring harness under the carpet can get damaged.

If your original CCM burnt, something was drawing too much current through it. Normally the fuses heading all the various branch circuits are sized so they blow before anything in that circuit burns. It wouldn't hurt to check every fuse to be sure someone before you didn't "creatively fix" a repeatedly blowing fuse by replacing it with a higher amp rating. Make sure all the fuses are rated at what they are supposed to be rated at.

A direct short usually blows a fuse, even if the fuse is over-sized. But a voltage drain like live conductors in dirty water would create, may allow a lot of amps to flow without exceeding the fuse limits. To inspect the CCM harness thoroughly you need to unwrap the outer cloth tape and examine each wire. There are a couple of factory splices in that harness section.
 
#6 ·
Then do you think it is worth inspecting the TCM. I don't want to get into the floorboard like I did for the CCM if you dont think it could be a potential reason for not starting. Also, is there a diagram of where each of the relays are positioned and their numbers.

I will check all the fuses and what is present verus what it is supposed to be. I did notice some where actually higher than what is required. So will replace those with correct amperage.
 
#8 ·
Thanks, that definitely saves some demolition time.

Checked all the fuses - 12 slots had no fuses (they have no or only one terminal so doesnt look like they need one), 17 were correct, 2 were lower amp value (1 for automatic TCM which I dont have and other was headlight washer which I dont have), 12 were higher amp value.

I will get all correct fuse values in tomorrow and see if that does anything.
 
#10 ·
Thanks for feedback but replaced Fuse #6 with no change.

One comment was that I called the VW dealership to get the actual CCM P/N to use based on the VIN#. They said the part should be 3B0959797AB (wanted $460 from dealer, $250 on ebay for used). Well before buying a used one, I took the old one out and it was 1J0959799AJ (5DK 007 954-61) which has been in the car working fine since I bought it 7 yrs ago. So I bought a replacement ($35 on ebay) with exact same letters and numbers except for the last digits which appear to be a serial number or batch number (old was III11500 versus replacement/used I24099). All the locks and lights work with replacement one but no start still. And also to confirm, the only programming needed is for the key fob which is currently working. So no reprogamming required that would affect no start situation???

I am starting to inspect the wires. I went ahead and removed to the driver door to inspect wires to door lock actuator (as well as wires going between car and door panel) since I had repaired the solder joints on door lock actuator last year when the car did not start, key fob did not work and alarm would go off when trying to start the car.

I noticed where it looks like a short existed before I got the car based on one wire having electrical tape on it and the others showing burn marks on outside of what looks to be thick factory heat shrink. I removed the electrical tape and looks Ok as wire splice has been soldered. I opened a couple of the burnt factory heat shrink and seem to be OK.

So my question is should I just go ahead and open up all those factory heat shrinks and redo all those joints? I would have assumed if these were shorted out, the door locks would not work. But they all do using locks on the door and using the key fob. Is there anything in this bundle of about 6 or 7 wires that could be the cause of my no start?? Wondering if this burnt out my original CCM?

Although my used CCM has a "warranty" label on it, I am going to go ahead and open it up to see if it has any issues with the board even though it is not showing any error codes using vagcom. Si
 
#11 ·
Where in MD are you? If you can connect to it with Vagcom, it works in some capacity. There are a few factory splices in the CCM wiring that could be bad as Steve stated. My 99, even though had no water ingress, had badly corroded splices on the floor.
 
#12 ·
Im in Salisbury. Yes it definitely works in some capacity since lights, locks, sunroof, etc. I am not sure what all the CCM controls, but seems everything works except obviously no start. i think it will just be a search and seizure to find that wire that is the culprit. I have a local VW expert that I will probably end up taking it to anyway since I have a rear passenger side fuel leak, but wanted to do this time consuming activity instead of paying someone to investigate.

I work a lot with PCBAs as I am in the telecommunications industry producing filters and antennas and see a lot of burnt boards that 90% of the time are burnt due to a short. Which leads me to believe there is a bad splice, solder joint or exposed wire that may have shorted. So hopefully I can track it down.
 
#14 ·
After finally losing patience looking for the Holy Grail, I finally took the car to a local shop who specialize in VWs. Low and behold, it ended up being the starter. The original shop I took it to that found the burnt CCM (I use for general maintenance) told me the starter was OK as I specifically asked. But I really think he found a smoking gun (literally) and stopped looking any further. But thankfully we are up and running again and the fuel leak was luckily only a hose. I still truly believe I have a short (exposed wire) somewhere which triggered the burnt CCM. Although as I mentioned, hard to believe, but I had put the old CCM back in and things (doors, fob, sunroof, lights, etc.) still worked.

To add to the frustration, as I was putting the door trim panel back on, all of a sudden the door started to alarm and locks/fob wouldn't work. Same as I had last summer when the Door Lock Actuator went bad on me. Luckily once I got it all back together that issue went away (I think lock knob is a little loose). So long story short, I will look back into that door and possible wiring problems. But for now, I need the car to be on the road, so that investigation will be on a lazy Saturday or Sunday when I have nothing else to do.

Thanks again for everyone's feedback and assistance. And take my advice, if you can't do it yourself, go to someone who KNOWS VWs!!!
 
#15 ·
My daughter, who's at college, her '03 Passat AWM with AT is having a similar problem. The problem began like this...she came out of the grocery store and when she turned the ignition her fingers quickly slipped off the key. She's pretty sure the starter did start to turn over for that split second. But, when she tried again and every time since then that somebody's turned the ignition switch, there'll be one click and then nothing...the starter motor doesn't turn.

I was thinking starter motor, too, but my wife, who went down yesterday to take her a good car, told me that the horn is not beeping to signal that the doors locked whenever she turns the key in the door (BTW, the battery in the key FOB has been dead for a while due to a stuck button). Alphaqtwo, since your starter was bad, do you know if your horn was beeping or not when locking the car? We've verified that the 6-month old battery is still good (12.53 V across the terminals and 11.8 V while trying to crank). Also, all the power options seem to work fine. It's 2 hours away in Birmingham, Alabama, so I ended up having it towed to a shop listed on a local VW club's website. Last I heard from him, he was leaning toward a bad starter motor, and he was about to test it. For testing the starter, he gave me the impression he knew how to do what is in Tomvw's "DIY: not cranking" sticky. I also asked him to check fuse 14 and 6, too.
 
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