LCA not functioning
My wife and I recently bought a 2017 Cayenne GTS. We love the car and have been enjoying it, but the Lane Change Assist has not been working. If the LCA button on the armrest is pressed, a warning saying service required will pop up on the dash. The dealer replaced both of the rear sensors for the LCA, but still no dice. Maybe they didn't recalibrate it or some other issue, not sure. However, I've noticed that the LCA lights on the mirrors will flash with the turn signals. Is this normal operation, or did a previous owner reprogram the lights to flash with the turn signals? I did a brief search but couldn't find anything about it. Let me know if you have any insight! Thanks.
Last edited by texascayenne; Apr 3, 2023 at 01:04 PM.
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Last edited by Needsdecaf; Apr 3, 2023 at 03:11 PM.
LCA module in rear bumper died.
New module and ½ hour of doppler calibrating.
The fancy doppler machine recalibrates the sensors.
I would call dealership and say, "Hey, how can we rectify the LCA?"
That is why you brought it to them the first time.
Maybe it needs recalibrating? Just shooting in the dark.
Good luck. Keep us up to date.
As far as OP is concerned, throw it back at the dealer. "It doesn't work, you've failed to fix it now do it properly!"
Bought my 2016 Cayenne GTS in early 2022. LCA worked but it was displaying the same error. I also noticed a strange behavior, LCA would work at night but not during the day... Weird.
Then I had all my door switches & electronics die one day. Turns out there's a leak in the connector grommet causing all the pins to corrode over time and lose connection. Replaced all the male pins on the car-side after sourcing hardware from eBay, the door-side still was lightly corroded, didn't warrant replacing entirely. I cleaned them up to the best of my abilities (really tight space) and reconnected everything, then voila door switches came back and LCA became fully functioning, even during day time.
My guess is LCA lights are brighter during day-time, therefore pulling more power. Corrosion in the connection caused higher resistance previously, tripping the error in the module.
For future sakes, I want to replace the driver-side harness entirely, since I'm not fully at peace with the remaining corrosion in the driver-side connector. But am having trouble finding & sourcing the door-side wiring harness matching my specific configuration - maybe I need to call the dealer.
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LCA module in rear bumper died.
New module and ½ hour of doppler calibrating.
The fancy doppler machine recalibrates the sensors.
I would call dealership and say, "Hey, how can we rectify the LCA?"
That is why you brought it to them the first time.
Maybe it needs recalibrating? Just shooting in the dark.
Good luck. Keep us up to date.
Bought a pair of used ones and took it to the dealer to have it programmed and it doesn’t work. The dealer says it shows no communication with slave sensor (drivers side). I checked the wire harness and all the wires for corrosion, cuts or kinks. Everything was fine. The Porsche tech told me it has to be the module under the dash. He said those rarely go out and it’s extremely expensive. The tech told me to check pin 5 because that’s the communication wire. It looks fine no damage. He said another option would be to run a new wire from pin 5 to the module under the front dash.
I will check it with my spare key to see if it starts working. I don’t have pp
Last edited by porsches4ed; Jul 4, 2023 at 06:37 AM.
I was just going to buy an aftermarket kit and use their sensors the tap into the oem lights with the wires the kit comes with or just use their mirrors with the blue dimmed / heated mirrors.
Just found this amazing item on AliExpress. Check it out! $176.00 | 2019-2022 for Porsche Cayenne car BSD BSM blind spot detection 24GHZ Microwave Radar Sensor alert LCA Mirror light alarm system
https://a.aliexpress.com/_mrG0yRa
I was just going to buy an aftermarket kit and use their sensors the tap into the oem lights with the wires the kit comes with or just use their mirrors with the blue dimmed / heated mirrors.
Just found this amazing item on AliExpress. Check it out! $176.00 | 2019-2022 for Porsche Cayenne car BSD BSM blind spot detection 24GHZ Microwave Radar Sensor alert LCA Mirror light alarm system
https://a.aliexpress.com/_mrG0yRa
Last edited by evilcorgi; Jun 11, 2024 at 10:33 PM.
For a couple of months it didn't work. I then got a PIWIS and cleared codes and the LCA became again operational and has been faultless since August. I haven't changed the lead battery or done anything electrical to the car. It is not garaged so it gets plenty of rain.
Then again, my longest drive has been about 60 miles.
I do wish this function had an audio component to it. Mine is 100% visual cues only.


