955 CTT wiring diagram?

[John White]

I'm having issues with my cornering lights, specifically the right side isn't getting any power. I pulled the pigtail and it checks out fine, there is power at the fuse, and I get continuity between the fuse and the left light socket but not the right side. No power at either headlight socket for the cornering light though.

 

So it seems to me there almost has to be short somewhere between the fuse and the right hand socket. But the way it winds through the dash and engine compartment I'm not sure how to track it down now.

 

If someone has a diagram of the wiring it would help a lot. Or if anyone has any other ideas they would be greatly appreciated too.

 

Thanks,

John

[lewisweller]

9 hours ago, John White said:

I'm having issues with my cornering lights, specifically the right side isn't getting any power. I pulled the pigtail and it checks out fine, there is power at the fuse, and I get continuity between the fuse and the left light socket but not the right side. No power at either headlight socket for the cornering light though.

 

So it seems to me there almost has to be short somewhere between the fuse and the right hand socket. But the way it winds through the dash and engine compartment I'm not sure how to track it down now.

 

If someone has a diagram of the wiring it would help a lot. Or if anyone has any other ideas they would be greatly appreciated too.

 

Thanks,

John

I've heard some stories of other bulbs being blown which stopped the direction lights working and wrong spec bulbs with wrong resistance also stop the lights working (only a Porsche could be this clever  Lol), also the light cluster slides into the housing Connector and doesn't fully click in sometimes. You have to push it in snug and then crank the boot tool on that cam arm mechanism until you get a nasty snap sound, yes you will think you broke it but its actually Ok .....unless you really broke it. If the connector is not snapped in tightly the weird light problems can happen. 

[John White]

6 hours ago, lewisweller said:

I've heard some stories of other bulbs being blown which stopped the direction lights working and wrong spec bulbs with wrong resistance also stop the lights working (only a Porsche could be this clever  Lol), also the light cluster slides into the housing Connector and doesn't fully click in sometimes. You have to push it in snug and then crank the boot tool on that cam arm mechanism until you get a nasty snap sound, yes you will think you broke it but its actually Ok .....unless you really broke it. If the connector is not snapped in tightly the weird light problems can happen. 

Yeah, I know about the latch, that was actually my first thought was the plug wasn't seating fully. Not the case though. I get no power at the plug itself. I'm going to try a few more things. The side markers were out at one point but then started working again. I also have another headlight switch, I'll swap that out to see if it could possibly be the culprit.

 

And yeah these cars are just about too smart aren't they!? :)

[hahnmgh63]

John, not sure what year you have but send me a PM with your E-mail address and I might be able to help you out.  Mark

[John White]

22 hours ago, hahnmgh63 said:

John, not sure what year you have but send me a PM with your E-mail address and I might be able to help you out.  Mark

Thanks for the info Mark!!

[John White]

Well I am about at the end of my electrical expertise on this one. Looking over the diagrams and info Mark sent me it seems the only logical answer is a short in the wire somewhere between the fuse panel on the drivers side and the right side cornering light socket. I tried swapping out an old headlight switch, no go. I know I have continuity from the fuse to the left side headlight but not to the right side.

 

There is supposed to be a ground somewhere around the headlight on the passenger side but I'll be darned if I could find it. Unless it's actually underneath the headlight tray?!?

 

What's weird is a couple times I also got a warning about the side markers being out. I took a look at them yesterday and sure enough they were both not working. I pulled the bulbs and both were burned out. Seems an odd coincidence that both were burned out and both happened while I'm having issues with the right hand cornering light. I'll see if they are still working tonight otherwise it may be the short is taking them out too.

[John White]

Did I mention I HATE electrical issues?! I should have mentioned it many times by now.

[ekstroemtj]

Have a look at the ground points:

 

http://rennlist.com/forums/porsche-cayenne-forum/702453-side-markers-fog-lights-and-passenger-side-headlight-does-not-work.html

[John White]

3 hours ago, ekstroemtj said:

Have a look at the ground points:

 

http://rennlist.com/forums/porsche-cayenne-forum/702453-side-markers-fog-lights-and-passenger-side-headlight-does-not-work.html

I had seen that before but I missed the idea of putting a temp ground on the pin for the cornering light. I might try that. I have thought it could be a ground issue too but I simply can't find the darned things. Both MB2 and MB6 could be the culprit but I can't find where they are. Mark sent me a BUNCH of docs and one has a chart that looks like it shows the location on a gridded pic of the car. But I can't blow it up enough to read it.

 

I think I'll try the temp ground and if that fixes it I might have to get the car up in the air and totally remove the passenger side wheel liner. I've looked from on top, in front, with a mirror, with a flashlight.......the good part is I put in a CAI and it's really easy to pull that out instead of the stock airbox. Lots of room to see in behind there but I can't find those darn grounds.

 

Thanks for another tip though, I'll try the temp ground next.

[lewisweller]

9 hours ago, John White said:

I had seen that before but I missed the idea of putting a temp ground on the pin for the cornering light. I might try that. I have thought it could be a ground issue too but I simply can't find the darned things. Both MB2 and MB6 could be the culprit but I can't find where they are. Mark sent me a BUNCH of docs and one has a chart that looks like it shows the location on a gridded pic of the car. But I can't blow it up enough to read it.

 

I think I'll try the temp ground and if that fixes it I might have to get the car up in the air and totally remove the passenger side wheel liner. I've looked from on top, in front, with a mirror, with a flashlight.......the good part is I put in a CAI and it's really easy to pull that out instead of the stock airbox. Lots of room to see in behind there but I can't find those darn grounds.

 

Thanks for another tip though, I'll try the temp ground next.

Hi John, I didn't twig this earlier but yes the earth mb2 is under the wheel arc cover along with some other electrical connectors. You can just unscrew the front portion and flop it back to access these electric and also the DV if you wanted to pop it out and have a check whilst your there. I just did alternator twice (don't ask why) and I had a good look at these electrical stuff whilst in there to make sure earth was tight no corrosion etc. See picture of the view with wheel arc flopped back, to the right upper corner of the intercooler you will find your earth and connectors. 

 

[John White]

7 hours ago, lewisweller said:

Hi John, I didn't twig this earlier but yes the earth mb2 is under the wheel arc cover along with some other electrical connectors. You can just unscrew the front portion and flop it back to access these electric and also the DV if you wanted to pop it out and have a check whilst your there. I just did alternator twice (don't ask why) and I had a good look at these electrical stuff whilst in there to make sure earth was tight no corrosion etc. See picture of the view with wheel arc flopped back, to the right upper corner of the intercooler you will find your earth and connectors. 

 

 

Cool thanks! I just had that cover half off to replace the burned out side marker bulb. But it's not hard to do. I might have some time tonight or tomorrow to look at it. The side markers are still working so I got that goin for me at least!! :)  The other MB6 must be up back under the headlight bracket or down low somewhere. I'll have to root around for that one too.

 

Thanks again for the help!!

[lewisweller]

2 hours ago, John White said:

Cool thanks! I just had that cover half off to replace the burned out side marker bulb. But it's not hard to do. I might have some time tonight or tomorrow to look at it. The side markers are still working so I got that goin for me at least!! :)  The other MB6 must be up back under the headlight bracket or down low somewhere. I'll have to root around for that one too.

 

Thanks again for the help!!

Mb6 couldn't be the earth strap from the alternator to the chassis rail could it? Diagram alittle deceiving as to exact place. 

Also on the chassis rail a few inches away from the alternator strap bolt point is another earth point not used on my ctt. I wonder why it is unused? 

[bigbuzuki]

On 12/10/2016 at 2:28 PM, John White said:

.......I know I have continuity from the fuse to the left side headlight but not to the right side......

 

Can you specify from which points you are measuring from.

Specifically what fuse and what headlight connection socket position.

 

There is no power circuit direct from the fuses to the headlight, the power circuit goes via control modules.

 

You may also be chasing a missing ground for no reason.

A quick check is if your high beam is turning on when selected, the MB6 ground is ok.

 

As there are multiple ground circuits from the headlight to MB6, may I suggest you carry out the following procedure:

You should have continuity when measuring from the right headlight socket positions A7, A8, A10 to any part of the chassis.

 

Edited October 15, 2016 by bigbuzuki

[John White]

On ‎10‎/‎15‎/‎2016 at 11:35 AM, bigbuzuki said:

Can you specify from which points you are measuring from.

Specifically what fuse and what headlight connection socket position.

 

There is no power circuit direct from the fuses to the headlight, the power circuit goes via control modules.

 

You may also be chasing a missing ground for no reason.

A quick check is if your high beam is turning on when selected, the MB6 ground is ok.

 

As there are multiple ground circuits from the headlight to MB6, may I suggest you carry out the following procedure:

You should have continuity when measuring from the right headlight socket positions A7, A8, A10 to any part of the chassis.

 

 

For power I have checked at the plug for the headlight and at the plug on the backside of the pigtail. No power on either right or left sides.

For continuity I ran a wire from the left hand fuse #21 to the plug pin #9 at the headlight. I get continuity on the driver's side but not the passenger side.

 

 Now that I know what MB6 is I doubt that's the one. Headlights, high beams, turn signals, etc. all work fine. It's only the cornering light that is out. I was just looking at grounds in the vicinity. But I also don't see the cornering lights listed anywhere else and now looking again it seems MB2 is for the secondary air pump.

 

Looking at the diagram for the plug to the headlight it looks like pins 9 and 10 are for the cornering light. Is 10 the ground coming back out? I might look tonight at where 10 goes once inside the headlight. Couldn't be that I knocked something loose inside there could it?? I'm gonna be pissed if it turns out to be something that stupid.

 

[bigbuzuki]

The fuse wiring does not run to either of the light assemblies direct, so I can't comment on what your measuring.

 

The fuse wiring runs direct to the "onboard computer network control unit" as per the diagrams I have.

 

From the control unit, there are seperate outputs to the individual cornering light assemblies.

 

Creating direct connections to the light assembly may cause damage to the control unit.

 

What is known about the cornering light system is that if either the left or right circuit is not connected properly, both lights will be disabled.

 

I would look at confirming the integrity of the connections of the headlamp assemblies to the car wiring when installed.

 

A loose connection in either assembly connector would disable your cornering light system.

 

 

 

[John White]

Actually looking back at the diagrams (I'm slowing learning how to trace a wire from page to page) there is a ground for the cornering light that goes to MB6. But on the MB6 diagram it's only listed as xenon headlight and on the headlight diagram it's listed as turn signal/parking light . I'm going to pull the headlight back out and start from the ground wire at the socket and work back from there.

[John White]

On 10/11/2016 at 8:29 PM, John White said:

Did I mention I HATE electrical issues?! I should have mentioned it many times by now.

Once again, did I mention how much I hate electrical issues? I FINALLY figured this out tonight. Went back inside the headlight and  was going to test the ground wire coming off the cornering light. Turns out it was a bit frayed at the connector. I fixed that and it seems to have solved the issue.

 

I think I have an idea what happened to cause all this. One of the bulbs went out awhile back and I grabbed new ones at the local parts place. I threw them out when I replaced them when all this trouble started so I can't check, but I have a sneaking suspicion they may have been a higher wattage bulb and caused the problems with the wire shedding the insulator like it was. Maybe, maybe not. Supposed to be 55w bulbs which is what I have now but I'd be willing to bet the ones I had last time were 100w.

 

Did I mention how much I hate electrical issues? I've been chasing my tail for way too long on this issue only to have it be a simple fix right back at the light.

 

Thanks for all the help and ideas though!!!

[lewisweller]

7 hours ago, John White said:

Once again, did I mention how much I hate electrical issues? I FINALLY figured this out tonight. Went back inside the headlight and  was going to test the ground wire coming off the cornering light. Turns out it was a bit frayed at the connector. I fixed that and it seems to have solved the issue.

 

I think I have an idea what happened to cause all this. One of the bulbs went out awhile back and I grabbed new ones at the local parts place. I threw them out when I replaced them when all this trouble started so I can't check, but I have a sneaking suspicion they may have been a higher wattage bulb and caused the problems with the wire shedding the insulator like it was. Maybe, maybe not. Supposed to be 55w bulbs which is what I have now but I'd be willing to bet the ones I had last time were 100w.

 

Did I mention how much I hate electrical issues? I've been chasing my tail for way too long on this issue only to have it be a simple fix right back at the light.

 

Thanks for all the help and ideas though!!!

When I replaced my directional lights (same like you one bulb knocks out two) my wiring was also a little crispy and flaky, I tried to move it a least I could to do the swap as the more I moved the more bare world I could see. I put some electrical tape back over any exposed areas and buttoned it all back up. Been working for 7 months so fingers crossed won't give me anymore lip.