M3LR: Steering Assist Reduced, Park Assist Not Available, ABS, Traction Control and Air Bag Warnings (and probably others)

[Wei Zhou Wayne]

I started getting this cluster of faults 3 weeks ago. The first one is always "steering assist reduced" and then the rest come on. While they first showed up , it may be disappeared after 20 or 30 minutes of driving. As of few days ago, it seemed to be elevated, the alert won't stop and my head lights, fog lights started to blink intermittently as programmed <I know, right, let other drivers to remind me>.

While all these alerts are present, my steering works perfectly fine whatsoever, and whensoever by far. It turns well, brakes well, all is well.

I tried "service mode" , yes, thare are 10 alerts active. See below. <including the notorious coolant low alert, well, I hope I have known about "service mode" long before now>

Now I requested SC visit, and the invoice estimate include $2k. In it, $1500 for HW3 <my current is HW2.5>, and $500 or labor and diagnostics. Of course, it includes top off collant :-D.

Thoughts? Guys, I have always have OTA with the latest software. Do you all think it is indeed ECU HW2.5 being bad, or do you think wire loom issue, or purely software issue?
The aftermarket used HW3 are only $300 ~$800<new>, should I buy one and replace myself if it resolves the problem?

 

[jjrandorin]

I started getting this cluster of faults 3 weeks ago. The first one is always "steering assist reduced" and then the rest come on. While they first showed up , it may be disappeared after 20 or 30 minutes of driving. As of few days ago, it seemed to be elevated, the alert won't stop and my head lights, fog lights started to blink intermittently as programmed <I know, right, let other drivers to remind me>.

While all these alerts are present, my steering works perfectly fine whatsoever, and whensoever by far. It turns well, brakes well, all is well.

I tried "service mode" , yes, thare are 10 alerts active. See below. <including the notorious coolant low alert, well, I hope I have known about "service mode" long before now>

View attachment 931225


Now I requested SC visit, and the invoice estimate include $2k. In it, $1500 for HW3 <my current is HW2.5>, and $500 or labor and diagnostics. Of course, it includes top off collant :-D.

Thoughts? Guys, I have always have OTA with the latest software. Do you all think it is indeed ECU HW2.5 being bad, or do you think wire loom issue, or purely software issue?
The aftermarket used HW3 are only $300 ~$800<new>, should I buy one and replace myself if it resolves the problem?

You would need tesla to reprogram your car even if you could replace the hw version yourself (pretty sure they have to change the hardware version on the back end too to match your car). No idea if all that is needed or not, but you dont have many options in getting it repaired either. You certainly are not taking a used HW3 to tesla and telling them to put it in, for example.

 

[android04]

What year is your car and how many miles? Is it out of warranty?

Whoever wrote up the estimate may have made an educated guess based on any records of previous cars they have serviced, and may have quoted the worst case scenario. It may turn out that your car won't need the computer replaced and there might just be an issue with a harness or connection or ground. But they won't know for sure until they start working on it. You don't have to sign the estimate before the service appointment and you can message them on the app to say that you don't want them to replace the computer unless yours is actually bad.

 

[Leafdriver333]

12v battery?

 

[Wei Zhou Wayne]

@android04 @jjrandorin @Leafdriver333
A quick update. I just went out to take care of some errands ,... well, ignoring the alerts.

Right at the sharp right turn and slightly upslope corner, I made a quick turn and all of a sudden, all of the "ACTIVE" alerts <being happily alerting/beeping/etc> stopped and disappeared!

Knowing its nature, I know they will come back. Now I am more confident that there must be some kind of connector/connection issue related to ECU.

Here is the picture in "service mode", see for nearly 11 minutes they weren't active.

And you are right, I will respond to the service message and let them know I won't replace the HW unless it is 100% dysfunctional.
My M3LR is Jan 2019 batch, and current mileage is 42,000.


Thank you folks for all your inputs. Much appreciated.

 

[Wei Zhou Wayne]

@Leafdriver333

In "service mode" , low voltage says 14.6v... But, but, but I will for sure open the hatch and check the connection tomorrow knowing there exist an unknown connection issue.

 

[Wei Zhou Wayne]

My M3LR is out of the regular warranty now with only power-tran warranty remaining, so I welcome any suggestions to work on it. I kinda miss the old days, plug in your bluetooth reader find the faults, find the parts, swap it and back in the game days.

 

[android04]

My M3LR is out of the regular warranty now with only power-tran warranty remaining, so I welcome any suggestions to work on it. I kinda miss the old days, plug in your bluetooth reader find the faults, find the parts, swap it and back in the game days.

Being able to access service mode is similar to plugging in an OBD code reader. And it could be tricky with both to figure out what the actual codes mean.

Since you are out of warranty, Tesla would charge you a diagnostic fee to find out what the problem is. Tesla technicians are likely to find out the exact issue more quickly than you might be able to.

If you want to look around to see if you can find and fix the issue, you can start under the frunk and look for any loose connections or damaged wiring. Sometimes rodents get under vehicles and start chewing on the wires. The next part would be to look at all the connections at the ICE computer, which is two computers sandwiched together (the infotainment computer and Autopilot computer). To access that, you need to open up the panel under the dashboard in the passenger side.

 

[Wei Zhou Wayne]

So I did. Bam! Here I opened the front hatch and carefully examined every joint and connection, no visible damage from cut, burnt, rubbing, twisting and rodent damage.
Then, I opened the ECU compartment, right under and behind glove box and visually visited the "wire loom".... Among "most" of the neatly laid out connectors and wire cables, there are "few" wires are strangely coexist among the cables. I meant,... for lack of a better word, the "few" wires' arrangement style just don't fit in. If you see yours, you will know what I mean here.

Ok, here are two pictures I have taken in my garage.

Under the glove box. The "out of style" wires are right behind the arrowhead.

Nothing out of ordinary, finger carefully checked every connectors and nothing fell out or felt loosely connected.
Put together back everything, the alert stays on. Sad. Top up the coolant jar with G48. That alert went away.
Now I have drove it 2 days, and the "11" alerts seem to went away and come back, and then went away again...

This morning, I sent kiddos to school and came back, None of the alerts were firing. NOW I AM EVEN MORE CONFUSED.

A FEW Thoughts to share,
1. Is it really types of issues caused by "loose connections"? Grounds were all good and connectors are ... mostly fine.
2. I topped up coolant, well, the level wasn't very low, the level was high enough to keep everything running fine. Or maybe the ECU wasn't cooled enough and went crazy to throw the alerts? Maybe? Can someone carry out an experiment?
3. Still, is it software related ?
4, There weren't significant difference in ambient temperatures among these days when alerts were active and today, alerts haven't fired at all.
5. The way active alerts fired, they stayed on and on, I couldn't even hear the turning signal sound, nor could I make a phone call. But when they disappear, the whole system acted like absolutely normal.

Feel free to ask me anything regarding this.

 

[KenC]

Too bad you don't have an OBD reader and SMT to look at some of the temps to see if there's a bad thermostat or something.

I'd still try a new 12v just to be sure.

 

[Wei Zhou Wayne]

@KenC I have checked the battery, and will replace one since it is over 4 years now. Just for insurance.
I do have veepeak OBD bluetooth. What you mentioned is true and I should check into that. Will report back. By far the alerts weren't coming back.

 

[Wei Zhou Wayne]

@android04 @Leafdriver333 @KenC
Update: Today, I put on 60 miles by far, none of the alerts is firing.
Thoughts: Filling up the coolant, cooling down the cpu, might have done the magic.

 

[Wei Zhou Wayne]

Unfortunately, after 2 days of silences, all alerts came back now.
Thoughts?
1. Clogs in MCU cooling housing that causes cpu overheat again?

 

[DocHolliday]

If you have a 4-year-old 12V, replace it.