CCM relay issue

[TDI4MI]

So, after months I may have found my culprit. At times my interior lights would not come on. Oddly, I could press the reading lamp or attempt to turn on the interior light switch, or other rear lights and it would show the door ajar light on the dash. I could not figure this out. Wiring looked fine, as I traced the entire harness, and the door functions all work and security system works fine. VCDS only showed intermittent time error for lights... I just so happen to replicate this issue one day and I thought what the hell, let me jostle the CCM. Poof, the lights came on. No breaks in the wiring looms as I unplugged all connectors, and jiggled all the wires while connected...the lights did not go out. Then on the highway, it happened again randomly... kicked the underside of the dash, and poof, lights came on...

So...it seems that from what little I read, there is a relay or pads that one could check. I was hoping to see if anyone had experience on this?

 

[oilhammer]

I think the CCM's internals are all solid state.

I've had various strange CCM failure conditions, not super common, but the ones I think of that I have seen more than once are one or the other side turn signals staying stuck on.

At this point, I'd just find another used CCM with the same part number and try swapping it to see if it fixes that problem. Record the soft coding on your existing one just in case the replacement is coded differently. You'll need to re-pair up your fobs, too (easy).

 

[BobnOH]

^That's a better answer than what I posted in the other thread.

 

[TDI4MI]

I think the CCM's internals are all solid state.

I've had various strange CCM failure conditions, not super common, but the ones I think of that I have seen more than once are one or the other side turn signals staying stuck on.

At this point, I'd just find another used CCM with the same part number and try swapping it to see if it fixes that problem. Record the soft coding on your existing one just in case the replacement is coded differently. You'll need to re-pair up your fobs, too (easy).

How does one record the soft coding? VCDS?

 

[Seatman]

I think the CCM's internals are all solid state.

I've had various strange CCM failure conditions, not super common, but the ones I think of that I have seen more than once are one or the other side turn signals staying stuck on.

At this point, I'd just find another used CCM with the same part number and try swapping it to see if it fixes that problem. Record the soft coding on your existing one just in case the replacement is coded differently. You'll need to re-pair up your fobs, too (easy).

That problem with the indicator is actually caused by a faulty relay in the ccm, I swapped out the relay in a friends mk4 for that very reason. New relay was really cheap from an electronics place. Problem is finding a post by someone who's already fixed the issue and can tell you which part is at fault.

There's a few inside but not sure what they all do. Wouldn't hurt to pop it open and look for anything obvious though.

 

[oilhammer]

Soft coding will be displayed in VCDS, yes. Any module that has it will be shown (and labeled) on the module's main screen. The Engine, Trans (if pedal deficient), ABS, Radio, etc. all have soft coding.

 

[TDI4MI]

That problem with the indicator is actually caused by a faulty relay in the ccm, I swapped out the relay in a friends mk4 for that very reason. New relay was really cheap from an electronics place. Problem is finding a post by someone who's already fixed the issue and can tell you which part is at fault.

There's a few inside but not sure what they all do. Wouldn't hurt to pop it open and look for anything obvious though.

Do you recall which relay and did they solder a new one in? I have a donor unit, but it also has issues...so I am trying to determine if I can isolate and correct.

 

[Seatman]

I don't recall which it was but it was me who soldered it, it's a mini one inside the ccm though, I'll need to go digging and see if I can find the info again.

 

[Seatman]

Do you recall which relay and did they solder a new one in? I have a donor unit, but it also has issues...so I am trying to determine if I can isolate and correct.

Here we go, it's actually on this forum, post #10

FAQ? One side signal/marker lights stuck on, after locking/arming

Turn Signal gets STUCK ON, after using Key (or Remote) to Lock or Unlock doors! This issue has been Identified and Resolved (Fixed) (11-Apr-2008), read through to latest post. Also rewriting / cleaning up this first post ... UPDATE, Feb 2016: See THIS POST for an overview of approaches that...

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