The other day I was at a store and pulled into a parking pot. I did as I normally do and crank it at the end to line myself up in the final foot or two. The steering went hard for the final crank. I turned off and got out of the car and hit the button to lock as I was walking away. Nothing happened. So I got back in the car and noticed the lights were on and the start button was orange. What happened was the computer did a hard reboot and didn't bother to turn itself off.

This is the third or fourth time over the last 6mo - 1yr that this has happened. Though normally when the steering starts to get hard it is kind enough to wait until I get back in the car to start it, before it will do a full reset.

I mentioned this issue at the end of a transmission issue post I made a while back, that was the first time this happened. But decided to make a new post so the title reflected the issue.
Has anyone ran into this before? Any guidance you can give?
2010 rx 350. 158k miles. This issue is intermittent. Power steering works great in between occurrences. But will start to show signs of it getting sluggish when sitting still and turning a day or two before the reboot.
Thanks. )

 

I am lost in the description of the problem as you are also trying to diagnose. It would lot clearer if you limit the post to just the symptoms/observations. You can always add your hypothesis in a separate paragraph.

My armchair diagnosis is the vehicle is randomly dying before you shut off. Next time, after reaching your destination, let the vehicle come to idle for about 30 sec before you hit the kill switch.

Once that is determined, we can delve into why it fails to hold a warm/hot idle.

Are you up to date with milage/time based maintenance?

Salim

 

Power steering randomly goes out once every few months.
When this happens... the next time I start the car the computer does a full reboot. Only this last time it did it immediately.
I assume a full reboot because the radio is back on FM, on some random station. Yet my saved stations and bluetooth connections are still in tact. My mpg average, after refuelling, average speed, etc are all reset to zero.
Car runs great 100% of the time except for when this happens.

Maintenance:
I don't keep the car in tip top shape. but I do take care of it.

 

Pretty random advice but this is the best I can do.

Please have your 12v battery load tested and charging system checked up. If your battery is 4+ yrs old, I would suggest replacing it. If you have not used quality gas, or you are at 150k + miles a throttle body cleaning may be in order.

Salim

 

And if you opt to clean the throttle body, clean the mass air flow sensor as well. Be sure to use the proper chemicals --- CRC makes a good throttle body spray cleaner as well as a good mass air flow sensor spray cleaner. They are two different products.

 

Thx for the advice. Was kind of what I was thinking. I just didn't want to start buying parts one by one trying to fix. That rabbit hole gets deep.
It happened again. On the road. Had to press hard on brakes. Phone was fast charging, so pulling amps. Power steering light came on. Navigation screen went to the 'disclaimer'. Then made it to my destination. Waited twenty or so secs to turn off car. When I turned off the computer did a 'system loading. do not turn power off.'

Battery is two or three years. I'll get it load tested. Will check alternator voltages under load and not. etc. Probably just buy one and replace. And go ahead and do a throttle body/mass air flow cleaning.

Thanks again. ))

 

If it happened while driving, it is your alternator. Take it to autozone or advanced auto parts to check charging system. You can also check it yourself with a multimeter, voltage should be 13.5v across battery terminal if car is running.

 

Although my advice may seem random, but it starts with evidence based diagnosis and then it does go into non-evidence based attempt to fix. I too hate throwing parts in the hope of getting a fix.

Salim

 

On most modern vehicles, when the alternator begiins to die an icon typically lights up on the dash to warn you.

 

Yeah not getting low voltage light. I did realize last night as I was thinking about the issue. I was also fast charging my phone when it happened the other day...original post. Just got a new phone. So decided I wanted 35w charging in the car. Seeing as I could. Obviously it was not the greatest of ideas.

I'm wondering if I shouldn't get rid off the charger. Even after I replace and clean things... is using the fast charger going to add too much stress on the electronics?

 

The warning light is when the alternator fails to charge the battery.

There are number of complications like a bad/weak battery AND bad/weak alternator will not turn on the light.

Voltage is one aspect, but there is the all important current which requires special setup to measure.

The alternator puts out multiphase AC which is rectified and under low load the voltmeter will not pickup the problem if one or more phase diodes fail.

I personally prefer bench testing but a good enough test can indicate issues is a underload test of the battery and charging system offered by auto-parts stores.

As far as 35watts load is concerned .. you have to see what else is going on. Brakes, lights, weak battery, AC, + other electrical load [so many things are being run of 12v now] can overwhelm the system.

Salim

 

Very easy to rule out alternator. Just visit a car parts store or use multimeter to measure across battery terminals while car is running.

 

I keep mentioning the car charger because that 7 amps, which after inefficiencies is probably more in the 9 amp area, is the cause. This first started happing last winter, according to my previous post. Which is to say the heated seats where the thing that added to the problem. Perhaps also charging... though that would have only been one amp. I went through all of the warm months with zero issues.... until I got the fast charger.

I finally managed to get out there and get some numbers.
12.57- off
13.98- no load 1500 rpm
13.6- load 1500 rpm
13.3- load 1500 rpm using steering while parked, but on gravel.
I add my phone to that and we are down to 13.4/13.1....from the looks of it.
0.037v AC- most likely at least one bad diode.

Then after all of that I went to measure voltage drop. Popped off the motor cover. Found a mouse nest and chewed up coil wires. Two strands of copper still in tact on white, and four strands left on green wire. So heading to Autozone for load test and need to grab a new connector for coil [clip broke off].

 

I wish all automotive wiring manufacturers would quit making their wiring insulation out of soy-based products. If they would just make that change, we all would suffer far fewer rodent damage incidents in our engine bays.

 

Argh! If only a weekly check under the hood was done, we would not have been here.

I recommend monthly for garage kept, but weekly for vehicles parked out in the open.

Salim