Automatic vehicle hold fault, parking brake fault -- possibly because of driving through puddle

rao_94583

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Location
San Ramon, CA
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AT, Audi e-tron GT
Week old Air Touring is showing this after driving through an unavoidable large puddle on the freeway. Have a call into Lucid -- no response yet beyond acknowledgement.

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How big was this puddle?
 
I don’t know, really. Deeper than it looked, but other cars were going through. And nothing happened right away … the fault showed up about 10-15 minutes later.
 
I don’t know, really. Deeper than it looked, but other cars were going through. And nothing happened right away … the fault showed up about 10-15 minutes later.
Strange. Let us know what customer care says.
 
Water probably made it into a connector and shorted a sensor. Bet it goes away when everything dries up, assuming there is some type of self check/self clearing of the error.

This happens to my Miata's rear o2 sensor when I drive through deep standing water. It will throw a check engine, I pull the code to confirm it's the rear o2, then clear it. Doesn't come back so long as the sensor/connector is dry.

Makes me wonder how you would pull and clear codes on the Air. Does it even have an obd2 port? Can you pull and clear codes?
 
Water probably made it into a connector and shorted a sensor. Bet it goes away when everything dries up, assuming there is some type of self check/self clearing of the error.

This happens to my Miata's rear o2 sensor when I drive through deep standing water. It will throw a check engine, I pull the code to confirm it's the rear o2, then clear it. Doesn't come back so long as the sensor/connector is dry.

Makes me wonder how you would pull and clear codes on the Air. Does it even have an obd2 port? Can you pull and clear codes?
No. Service can, and they connect with a CAT6 cable.
 
As it happens, @NoseyReporter was right on the money. The faults went away on their own, and both auto hold and park are now working correctly. Interestingly (although this might be completely unrelated), the turn signal sound got a lot feebler for about ten minutes or so, and then came back to its normal volume. 🤔

I will still have Lucid look at it, though, when I take my car in to fix the dead front radar sensor.
 
Water probably made it into a connector and shorted a sensor. Bet it goes away when everything dries up, assuming there is some type of self check/self clearing of the error.

This happens to my Miata's rear o2 sensor when I drive through deep standing water. It will throw a check engine, I pull the code to confirm it's the rear o2, then clear it. Doesn't come back so long as the sensor/connector is dry.

Makes me wonder how you would pull and clear codes on the Air. Does it even have an obd2 port? Can you pull and clear codes?
Just curious if you had the Miata long enough to know if such connector would be susceptible to corrosion from moisture.
My landscaper uses waterproof connectors for 12 V lighting so there must be a reason why this is not done for cars.
 
Just curious if you had the Miata long enough to know if such connector would be susceptible to corrosion from moisture.
My landscaper uses waterproof connectors for 12 V lighting so there must be a reason why this is not done for cars.
To be clear this shouldn't be an issue on a new car. In this case, I'd insist they check it and find the issue, or at least have it documented on the service records so if a part needed to be replaced in the future you could point back at this instance. Finding it may be difficult unless it's really obvious a connector isn't snapped together properly.

Most car connectors that are critical will have seals. The O2 being one of them. Each individual wire in the connector will also have a gasket.

Like this, see the gasket around the connector: https://www.bmotorsports.com/shop/product_info.php/products_id/496

And this, the yellow gaskets are for each individual wire:

I don't know much about EV braking systems because I really just play with ICE cars. With ICE cars there isn't much electronics going on around the brakes. Usually just a wheel speed sensor.
 
To be clear this shouldn't be an issue on a new car. In this case, I'd insist they check it and find the issue, or at least have it documented on the service records so if a part needed to be replaced in the future you could point back at this instance. Finding it may be difficult unless it's really obvious a connector isn't snapped together properly.

Most car connectors that are critical will have seals. The O2 being one of them. Each individual wire in the connector will also have a gasket.

Like this, see the gasket around the connector: https://www.bmotorsports.com/shop/product_info.php/products_id/496

And this, the yellow gaskets are for each individual wire:

I don't know much about EV braking systems because I really just play with ICE cars. With ICE cars there isn't much electronics going on around the brakes. Usually just a wheel speed sensor.
That'd make sense. Thanks for the info.
 
As it happens, @NoseyReporter was right on the money. The faults went away on their own, and both auto hold and park are now working correctly. Interestingly (although this might be completely unrelated), the turn signal sound got a lot feebler for about ten minutes or so, and then came back to its normal volume. 🤔

I will still have Lucid look at it, though, when I take my car in to fix the dead front radar sensor.
Glad it worked out! Yeah they should definitely still inspect as there must be an incompetent seal somewhere that led water to get in…unless this was just a coincidence, which it may or may not be since it didn’t happen until 15 min after the puddle?
 
Every one (5) of my faults (except for the dead screens = module) happened in the rain. Don't know if this is co-incidence, but I understand you folk out Arizona way have never seen rain...so don't understand the importance of water-proofing electrical systems.

{Peter being English (tease) ... never known an English car that ran in the wet. Lucid is a dry-climate car.}

Now would be a good time to test drive a batch of Lucids in the "atmospheric river". Maybe build a factory in Aberdeen, WA and test drive them in the Olympic Park?
 
Every one (5) of my faults (except for the dead screens = module) happened in the rain. Don't know if this is co-incidence, but I understand you folk out Arizona way have never seen rain...so don't understand the importance of water-proofing electrical systems.

{Peter being English (tease) ... never known an English car that ran in the wet. Lucid is a dry-climate car.}

Now would be a good time to test drive a batch of Lucids in the "atmospheric river". Maybe build a factory in Aberdeen, WA and test drive them in the Olympic Park?
It’s been pretty snowy and wet here in Boulder since I got my car. And knock on wood, no issues yet. I do have to wonder if there’s a seal somewhere in your car that is letting water in. Certainly a good hypothesis.
 
I saw the same exact sequence of errors today on my Air Touring. My car was in the shop getting PPF and tinted for the last ~7 days. I've had the car since Jan 7th, 2023 and have never seen a Shock and Tilt alert. While at the shop I got two kinds of "Shock and Tilt" notification on my phone at different times
a. Shock and Tilt Alert - Vehicle is being towed
b. Shock and Tilt Alert - Intrusion detected

I called back on both occasions. For (a), I was told that vehicle was at an incline. I did drive by the shop later that day and did observe that front wheels were on a small stand and the rear was on the floor. This shop had done ~2 or 3 Lucids before mine so I thought they knew what they were doing. For (b) I was told that the person that was applying the tint opened the door while it was locked. Maybe the fob was kept away and the car auto-locked while person was inside? Dont know. Today while waiting at the shop to pick up the car, I saw (b) again on my phone. I drove the car back home - ~15 mile drive - without any issues. Highway assist, navigation worked, the car felt "normal". Parked it in the garage. After an hour went to drive out and started seeing "Brake System Fault" followed by "Automatic Vehicle Hold Fault" when I tapped the brake. Called Lucid customer support and was told to get the car towed to Costa Mesa for further inspection. I was at 2.0.47. I upgraded to 2.0.48. Brake fault alert persists.
 
Could it be that they sprayed the car underside prior to the PPF (or even after, I suppose)? If they really do have an iffy seal in there, I can imagine it causing a fault after a little while. And maybe it will just disappear, like mine did. The service center could not see anything in the logs.
 
Could it be that they sprayed the car underside prior to the PPF (or even after, I suppose)? If they really do have an iffy seal in there, I can imagine it causing a fault after a little while. And maybe it will just disappear, like mine did. The service center could not see anything in the logs.
Hello @rao_94583, possible, I'll check with the PPF shop on Monday. If this is similar to the issue you had maybe it solves itself before the towing service arrives tomorrow afternoon.
 
Just so folk do not lose heart, both my problems were resolved by replacing bad modules, (first was video/ second 12v system controller) which were diagnosed and replaced. No issues since. All of my faults happened in the rain. I am convinced the actual warning (drive system/ brake system / 12v system/ etc.) is not literal...it's just trying to scare you and make you pull off the roadway. I'm now wondering how many of the hardware replacements (batteries/motors/etc) I've read of here were just a faulty chip? Pandemic chips: I bet there are chip failures everywhere in our society what with everyone scrambling to find substitutions during supply-chain failure.

To show how much confidence I have in Lucid Care I'm going out to find an EA charger and top off, and then drive out the PA turnpike to visit family. It's 262 degrees K. I really do not want to be trying a reset on the PA turnpike in this weather.
I am not afraid !
 
Thanks @Cosmo Cruz. I had to flatbed my Lucid to Costa Mesa last week. Service center representative said it will be there for about 2 weeks or so - not sure if they are overwhelmed with repairs. So far no feedback on diagnosis or possible root cause of the "Brake System Fault". Car has ~500 miles on it. I'm bummed :-(. If anyone else has encountered similar/identical faults and had it repaired, would appreciate your feedback on what the root-cause was and the fix.
 
Thanks @Cosmo Cruz. I had to flatbed my Lucid to Costa Mesa last week. Service center representative said it will be there for about 2 weeks or so - not sure if they are overwhelmed with repairs. So far no feedback on diagnosis or possible root cause of the "Brake System Fault". Car has ~500 miles on it. I'm bummed :-(. If anyone else has encountered similar/identical faults and had it repaired, would appreciate your feedback on what the root-cause was and the fix.
I just got those same two faults today after removing the original rear tire, replacing it with a spare, and driving down a steep incline. I then remembered that my spare was only at 20 psi, so I quickly went back home and pumped it up to 42 psi but the warnings persisted. I drove to my destination and back which was about 60km while those two faults kept cycling and beeping in the background.

I'm wondering if it has to do installing a spare without tpms and driving with the spare? I also happened to update to 2.0.61 while having the non-tpms spare on. I'm updating to 2.0.64 now; hoping that might resolve the two faults.
 
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