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I appear to have an excessive current drain when parked up that cuased my battery to go flat depsite a new battery being fitted. Have been through this on my 928 but I do not relly know my way around the Cayenne. I have a diagnostic tool I will try tomorrow but doubt that will show anything. Looked for a thread on such but could not find one.
Any suggestions where to start looking or things to check that are known to be problemmatic.
Hey Fred, has the Cayenne been exposed to a lot of wet weather recently? Have you checked the floors under the thick rubber mats for water ingress that then corrodes the splices in the large wiring bundles that run in the front corners of both the driver and passenger compartment?
I would checks the sunroof or pano roof drains, the front cowlmdrsins that have these rubber things in them for fording rivers that prevent small debris from being able to drain through and then back up the water (front inner fender liners need to be removed to get to those), and also the side rocer panel drains, and front a/c drain. Any of those can result in water soaking the front floor and effecting those large wiring bundles.
This has been attributed to a faulty keyless entry system module.
It activates the door locks while parked causing the battery drain.
Search KESSY for details.
I will get the diagnostic code reader on it tomorrow now that the battery is fully charged again. Will research the recommendation.
Will also check the current drain at rest with my new clamp on meter that compliments my laptop oscilloscope to see what that says amps wise.
I also did another Rennlist search this evening this time via the Google search engine and it came up with a thread that suggested turning the mirror adjuster away from the vertical position as this [apparently] has a heater mechanism that can for whatever reason [faulty snesor?] energise itself -not exactly needed over here in our hot desert type of climate!
In response to Pete's post not sure i have ever had the Cayenne out in rain over here. The problem here is that when it rains we tend to get it "all at once" as it were and the accumulated oils that have seeped into the tarmac over the months since it last rained tend to rise to the surface and all hell lets loose so in such circumstance one tends to avoid the roads!
Hey Fred, has the Cayenne been exposed to a lot of wet weather recently? Have you checked the floors under the thick rubber mats for water ingress that then corrodes the splices in the large wiring bundles that run in the front corners of both the driver and passenger compartment?
I would checks the sunroof or pano roof drains, the front cowlmdrsins that have these rubber things in them for fording rivers that prevent small debris from being able to drain through and then back up the water (front inner fender liners need to be removed to get to those), and also the side rocer panel drains, and front a/c drain. Any of those can result in water soaking the front floor and effecting those large wiring bundles.
Hi Pete,
No signs of dampness inside the car but will crawl around on hands and knees tomorrow just to make sure the ac drain has not blocked and flooded. As if the 928 was not enough to worry about!
To be fair I have owned the thing about 8 years now and apart from the battery the Cayenne has given me little issue other than a Carden bearing, a vacuum line split and a split cooling system reservoir- in fact I have to do a thorough service later this year when it cools off.
So OP, I’m guessing the Pepper hasn’t seen much rain if it’s in Oman. Mirror is rare. KESSY is possible, if you have it. I think the mirror control is a 15A at position 15 and Kessy is also 15A at 41 on driver-side fuse panel. That’s what my diagram shows. And for what it’s worth, I also don’t turn on mirror heaters unless needed.
Last edited by hatchetf15; 09-22-2021 at 07:02 PM.
So OP, I’m guessing the Pepper hasn’t seen much rain if it’s in Oman. Mirror is rare. KESSY is possible, if you have it. I think the mirror control is a 15A at position 15 and Kessy is also 15A at 41 on driver-side fuse panel. That’s what my diagram shows. And for what it’s worth, I also don’t turn on mirror heaters unless needed.
Did not know there was such a thing as mirror heaters until the other day. I have barely read the owners manual I am somewhat embarassed to say. Need to spend a bit more time giving some TLC to the poor thing. I presume they are switched on when the **** is over the fuzzy lines and they switch on based on ambient temperature- not much chance of that here but if the temeprture detector is shot..? Either way I set the **** ob mirros tucked in now..
Today I fitted new tyre pressure sensors and in the process had the front wheels rebalanced as there appears to be some vibration i am not happy with. Last time the thing was serviced i had an advisory that the front lower inwboard rear bushes may be on their way out. I have severaloption for replacement- wondered if the list had any preferences for such and what the signs of failing bushes are.
Also, are there any easy ways to check for and affirm such is the case? Some kind of pry bar test I suspect.
Have been doing a bit more investigation into this matter and with my new DC clamp on meter measured some13 amps with the door open and sounds commensurate with the advice above. The positive cable out of the battery splits into 4 sub cables with two seemingly 16mm2 cables and two 4mm2 cables. Disconnecting the 4 sub cables and measuring current flow suggeted that the first 16mm2 cable was passing 8+ amps, the second 16mm2 cable virtually nothing, the first 4mm2 cable about 4+ amps and the 2nd 4mm2 cable virtually nothing. See photo below.
Much appreciate if anyone can confirm these numbers make sense and if the 4 cables can be identified as to what they are feeding or where they actually run to in the vehicle. Unfortunately i do not have a wiring diagram at the moment.
I will shortly do another test- this time with the doors closed and the car locked to see what the current draw falls to. I am assuming that soemthing like the 928 there will be a short time needed before the lock arms and the current drops- presumably to something like 50mA or so.
Just recently did this repair on my 05 CS. Seems to be a very common issue with these models and something you may want to check (possible current draw?). Also when doing this fix/repair, I switched to using replacement LED bulbs (no heat). BTW, leaving the side mirror heating switch in the off position is probably a very good idea. Keep us posted on what you find. Good luck. https://rennlist.com/forums/cayenne-...nd-photos.html
I'm replying mainly to hear how this turns out. I've had a few KESSY related codes since I bought my Cayenne... something about an antenna in the rear bumper and something else.
It's gotten worse lately... sometimes I have to wake the system up by first opening the rear hatch so that it lets me in. Otherwise, if I use the key manually the alarm goes off.
Most recently I have to unlock my left rear door with the switch up front.
Anyway, my battery only went dead once a few weeks ago but I thought it was that I left my Garmin GPS on for a week or so.
Are there any aftermarket devices wired in such as radar or laser detector or such. I had a parasitic draw and removed the laser detector and all associated wiring. Problem solved for me.
Have been doing a bit more investigation into this matter and with my new DC clamp on meter measured some13 amps with the door open and sounds commensurate with the advice above. The positive cable out of the battery splits into 4 sub cables with two seemingly 16mm2 cables and two 4mm2 cables. Disconnecting the 4 sub cables and measuring current flow suggeted that the first 16mm2 cable was passing 8+ amps, the second 16mm2 cable virtually nothing, the first 4mm2 cable about 4+ amps and the 2nd 4mm2 cable virtually nothing. See photo below.
Much appreciate if anyone can confirm these numbers make sense and if the 4 cables can be identified as to what they are feeding or where they actually run to in the vehicle. Unfortunately i do not have a wiring diagram at the moment.
I will shortly do another test- this time with the doors closed and the car locked to see what the current draw falls to. I am assuming that soemthing like the 928 there will be a short time needed before the lock arms and the current drops- presumably to something like 50mA or so.
Terminal strip
#1 powers the the left fuse box
#2 right fuse box fuse #2
#3 right fuse box fuse #9
#4 to relay 15 in the fuse box above battery.
Welcome to the convoluted Cayenne wiring. It would take many pages to trace through the various fuse boxes.
Since diagrams are copyrighted material they cannot be posted on this forum.
Suggest you try ebay.
Hi chaps- thanks for the various inputs that are helpful. Got a bit non plussed over the thing and then had some back issues that resulted from a smash in my previous 928 some 16 years ago so had to put matters ontot he back burner as it were.
After doing a bit more testing i am puzzled. I put the thing to sleep by locking the open driver's door manually to let the braisn think it was all locked up and everything and the thing seems to go to sleep quite quickly. when at sleep it seems to drain around 0.1 amps as per my new DC capable clamp on meter. My 928 measures about 40 mA so have good reason to believe the meter is accurate.
At charge the battery indicates 12.8 volts and drains down to about 12.2 volts in 5 days. Thus it is going from 100 amp hours to what one presumes to be 50 amp hours in about 5 days and down to 25 amp hours in about a week [12 volts]. I never used to have this type of drain but the recently [last couple of years] I have not been using the car much at all since I retired and then covid struck. 0.1 amps is 2.4 amp hours per day so that draw of 50 amp hours should last at least 20 days suggesting that in fact the actual draw is closed to 0.5 amps. Puzzled as to what is actually going on.
As per some of the comments as far as i know there is no other battery but not even sure i would know where it was if it ha done other than somewhere in the tool tray area under the hatch area. As I can fathom out this is not the case with the Turbo S but...? Had a look at the relays in the driver side engine bay but no sign of any heat there. I was surprsied at the small number of relays so maybe there are others elsewhere as in the fuse locations.
As I am aware there are no after market additions but that is not to say such do not exist- just that I can find no signs of such.
This made me wonder if there are any other features that could be left on "unwittingly" to create a constant draw. Have listened carefully to see if I could hear anything like fuel pumps whirring away but nothing to date.
I change the batteries in the remote unit from time to time and change them on both keys- only have one key within range. The locks open when I approach the driver's door. I invariably press the lock button when I leave the car- trust that is not something unwittingly dumb. Starting seems fine and voltage with the engine running is about 14 volts as expected.
No signs of any lights being left on- the interior lights go out about 10 seconds after closing the doors and immediately after pressing the lock button. I do not seem to have a lamp in the engine bay area as I do on the 928 - whether i should have one I do not know.
At least i understand and familiar with my 928 but the Cayenne remains something of a mystery. Must check what is available manual wise.