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Discussion Starter #1 (Edited)
My 2003 Passat b5 1.8T has developed a very perplexing behavior. Often the vehicle still behaves and starts normally for the initial drive of the day (i.e., wake-up, head off to work). But for any subsequent trips, it usually reverts into what I call "donkey mode" (stubbornly refusing to go.....as described below).

"Donkey mode" (stubbornly refuses to go) :
- ignition won't crank/start
- can't lock the doors (hit the door-lock button on the door and either nothing happens, or the locks go down momentarily and then automatically pop right back up). My key fob battery ran out long ago but now that I've replaced it, I can't get it to re-program.
- can't control any passenger windows from the driver's door panel
- moon roof doesn't work
- the red LED at the driver's door lock does not blink or illuminate at all (I'm not sure what's considered 'normal' behavior for this).

+ radio works
+ lights work (headlights, dome lights, etc.)
+ driver's window control works
+ individual window controls work but only from their own respective passenger door buttons: the driver cannot control any passenger windows no matter how the child safety button is positioned.

Weirdly consistent 'resolution' to the problem:
After sitting in "donkey mode" for roughly 20 minutes, I will hear either a little clicking sound (like the shift interlock) or the the rear horn beep (as though locking the car) and with that, suddenly, I can turn the key and she fires right up. The strange thing is that it's quite consistent: it goes into "donkey mode", but then after what seems like it's reliably about 20 minutes, it clears and can be started right up. We've been through this cycle dozens of times. Sometimes awkwardly stranded at a gas pump, in a friend's driveway, or trying to leave work. I think there may have been a few times where it sure seemed more like 35 or 40 minutes before it resolves...and maybe a few that were more like 5 or 10 minutes.

At one point we thought it might be heat-induced, but now it's happened to us on 50-degree (f) days, 60-degree (f) days, and 90-degree (f) days. Also, it doesn't seem to be tied too closely to vehicle/motor temperature either.

Water intrusion? I accidentally left the moonroof open, while parked, through a downpour at work shortly before all of these issues presented. I know, I know: automatically assume everything in/around the CCM is completely ruined, right? But, I pulled the carpet up as soon as I got it home (after the downpour), and there was no wetness under the carpet. Nevertheless, I left it in the garage overnight with a board propping-up the carpet and two box fans blowing on it all night....this effectively dried the carpet. Also: there is zero visible sign of any corrosion or water intrusion under the driver's side carpet. The CCM unit itself is uber clean and new looking, as are all of the wires.

Things I've tried/looked at:
+ while vehicle is in "donkey mode", I've tried every combination of locking/unlocking, controls, door actions, key fobs to try to find one that snaps it back to reality, but all to no avail. I can't find any action or combination of actions that help resolve it, except waiting for the required ~20 minutes.
+ I tried plugging in my OBDII scanner and clearing all engine codes while in "donkey mode", so see if that would resolve it (nope).
+ checked every fuse in the fuse panel: by visual inspection (pulling them) as well as testing them in-place with the multi-meter, for the larger ones.
+ pulled the starting interlock relay cube ("53" printed on it) and plugged it back in, just to see if that would do anything (nope).
+ I pulled the carpet back and inspected the CCM, wiring harness and wires. I unwrapped the wire 'snake' down by the driver's door ('spinal cord') and separated all the individual wires so that I could inspect the butt-connectors/splices. They all look perfectly new, clean, and sealed.
+ I took the spinal cord's brown ground wire off of the bolt in the floorboard, inspected it, scratched at it and put it back on the post.

Some of my deductions, rationale, and synthesis of what I've seen:
- It doesn't seem like a plain old broken/shorted circuit (broken wire, corroded connection, blown fuse) because of the way it fairly consistently resolves after about 20 minutes. Also, probably not a 'touchy' connection, since I've physically moved the wiring (gently) while in "donkey mode", to no avail.
- because of the 20 minute wait time....I'm wondering if it could be a relay...or some electromechanical component the 'gathers-up' electricity in a capacitor in some way.
- or, to explain the 20 minute wait time, is there something that re-checks for the system's state/status and after 20 minutes of inactivity, it's reset?
- maybe there is something in the security/anti-theft system that is inhibiting starting because of the fact that there isn't a properly 'paired' key fob?

I'm at my wits end (my wits aren't that long) and I'm open to your suggestions, tips, and best guesses.
 

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No codes at all on ANY of the modules (cluster, CCM, etc) ?
 

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It looks like you have a corrosion problem in the CCM wiring.

I suggest you completely unwrap all of the CCM harness and pull the wires apart to find the splices, any corroded splices need
to be cut back, soldered, and covered with marine grade heat shrink tubing. (You might need to add short wires to replace what you cut out)
Also check ground connections (1 on floor and on "A" Pillar), and check CCM/TCM and "A" Pillar connectors.

Have a good look at this link, before you start.
Passat Comfort Control Module - harness repair.docx
 

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Discussion Starter #4 (Edited)
No codes at all on ANY of the modules (cluster, CCM, etc) ?
I only have a very cheap OBDII scanner.


It looks like you have a corrosion problem in the CCM wiring.

I suggest you completely unwrap all of the CCM harness and pull the wires apart to find the splices, any corroded splices need
to be cut back, soldered, and covered with marine grade heat shrink tubing. (You might need to add short wires to replace what you cut out)
Also check ground connections (1 on floor and on "A" Pillar), and check CCM/TCM and "A" Pillar connectors.
In my mind, wire corrosion is inconsistent with the fact that the problem seems to reliably 'resolve' after 20-30 minutes - how would you reconcile this fact? (I'm not discounting your diagnosis, but I'm just trying to understand what you think might be going on). Can anyone expound on a plausible scenario that would account for both of these factors?
 

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I only have a very cheap OBDII scanner.



In my mind, wire corrosion is inconsistent with the fact that the problem seems to reliably 'resolve' after 20-30 minutes - how would you reconcile this fact? (I'm not discounting your diagnosis, but I'm just trying to understand what you think might be going on). Can anyone expound on a plausible scenario that would account for both of these factors?
It is totally consistent.
Lift the carpet, open the CCM and unwrap the harness, and I think you will find it pretty obvious.
 

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Discussion Starter #7
Again: I'm not trying to start an hostile argument, but I'd genuinely like to know what kind of scenario you have in mind when you say
It is totally consistent.
You haven't explained that to me yet.

From my original post (emphasis added this time):
Things I've tried/looked at:
...
  • I pulled the carpet back and inspected the CCM, wiring harness and wires. I unwrapped the wire 'snake' down by the driver's door ('spinal cord') and separated all the individual wires so that I could inspect the butt-connectors/splices. They all look perfectly new, clean, and sealed.
  • I took the spinal cord's brown ground wire off of the bolt in the floorboard, inspected it, scratched at it and put it back on the post.
There was nothing obviously wrong. In fact, all of the wiring looked brand new and all the butt splices were clean and tidy. I mean, I could just keep unwraping things and digging into the wiring more and more, but now it's at the point where it seems there's greater potential to do harm rather than good.
 

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What's consistent is that all your troubles are CCM related, i.e. everything that doesn't work in Donkey Mode is controlled by the CCM (including the starter interlock relay). Wetness/corroded connector contacts/corroded splices are typically the culprit...

But I am really very puzzled at where the 20 minutes might be coming from. The only thing that comes to mind would be the reset timer for the alarm, but your car isn't alarming. There are couple of circuit breakers--one for the window motors, the other I forget--but the CCM control power is provided from fuses. I assume you've unplugged the CCM connectors to check for water, etc.

Short term, I would be strongly inclined to open up the starter interlock relay and "prop" the contacts closed, e.g. with a piece of a paper match or cereal box. The CCM would be none the wiser and you wouldn't be stuck, at least. (I'd bet the engine will run just fine in Donkey Mode.)

You could try replacing the CCM (with exact part number), but that's a long shot.
 

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I think there may have been a few times where it sure seemed more like 35 or 40 minutes before it resolves...and maybe a few that were more like 5 or 10 minutes.
This is not consistently 20 minutes, I would say it is quite random.
I don't have time to explain and justify every suggestion.

Have you checked the CCM PCB for moisture, corrosion or bad connections ?

It is generating CCM codes, it would help if you got it properly scanned and post the codes.
I would suggest using VCDS. You can download the free version of VCDS Lite software from...

As a temporary fix for the no start issue:
Remove the relay that is in position #12 and connect a bridge across the socket pins that connect to the relay contacts.
 

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Discussion Starter #10
UPDATE to original post:

All my same issues persist and my troubleshooting efforts continue. More and more I'm convinced it's not cranking due to some part of the alarm system. I'll reiterate: the car always starts....eventually. It just doesn't always start when you first try.It sometimes requires a wait. Something is 'resetting' after a relatively short period of time. This 'resetting' action causes the door locks to suddenly actuate; that's your sign that it's definitely ready to crank/fire/run the next time you turn the key.

I talked to my local VW shop experts about the symptoms, in hopes they'd seen these same symptoms elsewhere and also to get an idea of what $ I might be facing if I handed the whole mess over to them. Of course, no one knows how many hours of labor would be required for troubleshooting an issue like this, but the shop figured it's likely be 2-5 hours ($109/hr). Then, if it's the CCM, several hundred $ more for the part, install labor, programming. Bottom line, if CCM is bad, would likely be around $1,000. (that's a lot of dough, but man is it tempting to just give this to someone else!)

I followed an errant theory, for a while, that it might be a bad ignition switch. So, I took off the steering column covers inspected the wiring and replaced the ignition switch, to no effect.

Since the ignition switch is ruled-out, my top theories are:
  1. Generally bad CCM
  2. Bad alarm interlock relay (position #12)
I ordered a VAG-COM cable which I intend to use with VCDS Lite, in hopes I can get more information about the issue. Since I'm new to VAG-COM, what would I expect to see if the CCM is bad? Is the tell-tale sign of a bad CCM some type of "cannot establish a connection" error in VCDS? How will I know if my CCM is fried?

While the VAG-COM cable is shipping, I will try to rule-out the alarm interlock relay. From another post by @TomVW, I think I can jumper it by connecting pin 30 to pin 87 in the sockets (I'm not 100% sure this description applies to both relays #13 and #12, but that's how I read it).

Anything I missing? Thoughts? Logic critiques? Strategies?
 

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While the VAG-COM cable is shipping, I will try to rule-out the alarm interlock relay. From another post by @TomVW, I think I can jumper it by connecting pin 30 to pin 87 in the sockets (I'm not 100% sure this description applies to both relays #13 and #12, but that's how I read it).

Anything I missing? Thoughts? Logic critiques? Strategies?
To eliminate CCM problems, you can bypass relay #12.
 

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Discussion Starter #13
Update: I tested the inhibitor relay, #13 (and there is no alarm system....no relay in #12 position).
---> While the vehicle is not acting up: I pulled relay #13 and jumpered terminals 30 & 87, turned the key to 'crank' and she started right up. Likewise, with the relay plugged in and my finger on it, I can feel it click appropriately as cranking is initiated.
---> Conversely, when the vehicle is acting up: the relay does not click when turning the key to crank, and a jumper wire across 30 & 87 does nothing.

So my question is: what conclusions can we draw from this, and what does it rule out? My assumption is that this tells us the inhibitor relay is most likely working correctly, right? Does this lend more credence to the theory that I'm facing an issue with my CCM?

At this point, I'm becoming more and more inclined to source a used CCM from somewhere and just try swapping it. My only apprehension is what I don't know about 're-programming'....is this always necessary with a new CCM and what does it entail?

As always, I'm open to alternate opinions, critiques, suggestions, slanders, trolling, and general life advice.
 

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The relay in position 13 is the starter interlock relay. It is not controlled by the CCM.
To borrow a phrase from Chicago, the CCM says "innocent!"

If automatic transmission, it will be relay 175, controlled by the Park/Neutral switch.
If manual transmission, it will be relay 204, controlled by the clutch position switch.
In either case, the switch switches the ground side of the relay coil. The +12V comes from the ignition switch "start" contact.
But read on...

Rereading your previous post, you say "a jumper wire across 30 & 87 does nothing." Those are the relay contacts (not coil), so that indicates the ignition switch is the trouble--it switches the +12V to both the contacts and coil of this relay (regardless of transmission). Therefore, if the +12V is missing, the relay won't activate even if the Park/Neutral or clutch switch is providing ground.

You should see +12V at terminals 30 and 86 of this relay with the key to "start," but I'll bet you don't (when it's acting up).
Ignitions switches are a known failure item--sounds like you need one.
 

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My guess is a bad connection in the wiring that doesn't allow enough current to flow to energize one of the suspect relays. I'd check and clean all the ground points and maybe the power connections too.
 

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Discussion Starter #16
Matters seems to be getting muddled, owing mostly to my lack of electrical knowledge and inability to articulate things in clear terms. Here's an attempt at clarification.

The relay in position 13 is the starter interlock relay. It is not controlled by the CCM.
To borrow a phrase from Chicago, the CCM says "innocent!"
I don't know what you mean by this. My testing seemed to suggest that there was nothing unusual going on with the relay...so doesn't that eliminate it as a possible suspect and leave the CCM?

If automatic transmission, it will be relay 175, controlled by the Park/Neutral switch.
If manual transmission, it will be relay 204, controlled by the clutch position switch.
In either case, the switch switches the ground side of the relay coil. The +12V comes from the ignition switch "start" contact.
But read on...
I don't suspect my issue is caused by the transmission interlock relay.

Rereading your previous post, you say "a jumper wire across 30 & 87 does nothing." Those are the relay contacts (not coil), so that indicates the ignition switch is the trouble--it switches the +12V to both the contacts and coil of this relay (regardless of transmission). Therefore, if the +12V is missing, the relay won't activate even if the Park/Neutral or clutch switch is providing ground. You should see +12V at terminals 30 and 86 of this relay with the key to "start," but I'll bet you don't (when it's acting up).
Ignitions switches are a known failure item--sounds like you need one.
When I say that using a jumper wire to bypass relay #13 "does nothing" I mean "it doesn't improve or resolve my problem...my intermittent problem persists in the same way and manner that it existed without the jumper wire, when the relay is in its place". Also, if you read back in the thread you'll see that I replaced the ignition switch with a brand new one, to no effect. I'm reasonably confident my problem is not with the ignition switch itself.
 

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Discussion Starter #17
My guess is a bad connection in the wiring that doesn't allow enough current to flow to energize one of the suspect relays. I'd check and clean all the ground points and maybe the power connections too.
Others suggested this type of thing early on in the thread, but all the wiring I could see looked great (factory-fresh). And, I don't believe a bad wiring connection would be consistent with the fact that it always cranks/starts after a short wait period. Can you elaborate any more on why this would always eventually resolve (after 10-30 minutes)? When a bad ground exists, and not enough voltage is present, does the insufficient voltage gradually "build-up" in a capacitor or something to the point where there is finally enough of it to do what it's meant to do? I don't understand how this would work.
 

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When a bad ground exists, and not enough voltage is present, does the insufficient voltage gradually "build-up" in a capacitor or something to the point where there is finally enough of it to do what it's meant to do? I don't understand how this would work.
Kinda sorta. I don't think capacitance makes much difference but resistance causes heat and heating up a connection can change its characteristics. And sometimes, if things are right on the cusp, sometimes they work and sometimes they don't. Plus certain circuits may turn off or change state after a certain period of time which can cause the behavior to change. In short, it was just a swag so take it for what's worth.
 

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Connect the jumper across relay #13, check if there is voltage on the jumper while trying to start (when it won't crank).
If there is about 12V at the jumper and it is not cranking.
The fault is is in the wire that goes from the relay, through some connectors to the starter solenoid.
Most likely a bad connection where it connects to the starter solenoid. (small wire)
 

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Discussion Starter #20 (Edited)
Connect the jumper across relay #13, check if there is voltage on the jumper while trying to start (when it won't crank).
If there is about 12V at the jumper and it is not cranking.
The fault is is in the wire that goes from the relay, through some connectors to the starter solenoid.
Most likely a bad connection where it connects to the starter solenoid. (small wire)
This is helpful - thank you. I tried this procedure today.
  • Whenever the vehicle correctly cranked & started, the voltage on my jumper wire across relay #13 quickly ramped up from 4V up to about 10V (I suspect it just doesn't have time to get all the way up to 12V before the engine starts, the key is released, and power to this circuit is cut).
  • Whenever the vehicle did not crank, there was no voltage on my jumper wire across relay #13.
So, I think this vindicates relay #13 as well as most of the circuit that exists 'downstream' of the relay, and it casts further suspicion on everything that is 'upstream'. Is the CCM upstream? Is the CCM responsible for sending the voltage to relay #13? Aside from the actual wires themselves, are there any other upstream components that should still be ruled out?
 
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