Really weird question

"Kaizer Soze" (therealkaizersoze)
11/27/2014 at 13:35 • Filed to: None

I am a passenger on my way to a relatives house and for whatever reason the aftermakret H/U didn't turn on. I am wondering if it would be detrimental to the autobox if we shut the engine off and on again while we are on the highway.

We are running really late and don't want to stop also it has nav and we will need it in the Vermont backcountry where there is no signal. Not to mention its a 4 hour drive and some music would be good.

It's an 03 Saab 9-5 with an Aisin AW-55 or something.

Thanks a bunch.

Update: We pulled off to the side of the road to cycle the power.

DISCUSSION (17)

Buick Mackane > Kaizer Soze
11/27/2014 at 13:41

what the heck is a "HU"?

thebigbossyboss > Kaizer Soze
11/27/2014 at 13:41

Do not turn off your car at highway speeds.

It only takes a second to stop and turn it off. The time saved is neglible. Just do it at a highway rest area and you'll lose less than 2 minutes total.

thebigbossyboss > Buick Mackane
11/27/2014 at 13:43

Heads up. Or whatever. Either way he should not turn off his car while driving down the highway. That's idiotic.

Twingo Tamer - About to descend into project car hell. > Kaizer Soze
11/27/2014 at 13:45

Don't switch off your car on the road whatever you do. Losing braking even for a short time will not be good if an emergency situation arises.

Twingo Tamer - About to descend into project car hell. > Buick Mackane
11/27/2014 at 13:46

Probably head unit

AMGtech - now with more recalls! > Kaizer Soze
11/27/2014 at 13:47

I wouldn't do that. It could be dangerous. The head unit problem is probably not going to be fixed by cycling the key. Maybe it's built in fuse has failed. Or maybe it's missing the switched power from the vehicle, in which case you may not be able to restart the car because the ignition switch or some other thing is on its way out the door. Is anything else in the car not working? Wipers or interior lights or dash illumination? That probably isn't the case, but there is a small chance. Chances are it's an issue with the head unit or its connections, but I would still be surprised if cycling the key fixed it.

thebigbossyboss > AMGtech - now with more recalls!
11/27/2014 at 13:51

Even if cycling fixed it turning off a car at highway speeds is a stupid stupid plan.

AMGtech - now with more recalls! > thebigbossyboss
11/27/2014 at 13:53

Agreed. I was just trying to be more... diplomatic.

Kaizer Soze > Buick Mackane
11/27/2014 at 13:54

Head unit. And I knew this would be a resounding no.

Kaizer Soze > AMGtech - now with more recalls!
11/27/2014 at 14:02

I guess it happens every once and a while. It's because the switchable power and constant power going to the head unit are the same thing. There is just a power interruption blip to tell the HU to wake up at startup. The key probably wasn't turned quickly enough.

We are the only car in visible range and there is a couple of pumps left in the brake booster.

Don't eorry we stopped we are not going turn the car off at highway speeds.

AMGtech - now with more recalls! > Kaizer Soze
11/27/2014 at 15:01

That's a goofy way to have a head unit wired up.

DrScientist > Kaizer Soze
11/27/2014 at 16:05

you may have heard of the debacle GM has been going through recently.

you would essentially be replicating the worst outcome of their faulty switches. you'd lose brake and steering assist, not to mention be unable to steer at all when the steering wheel locked.

Kaizer Soze > DrScientist
11/27/2014 at 16:34

It's a Saab so no steering lock and technically a GM too.

Kaizer Soze > AMGtech - now with more recalls!
11/27/2014 at 16:39

It's actually wired to the light switch. It's a Saab so the lights come on with the car. Like I said there is no switchable power, the OEM head unit got info from a computer in the car to know when to turn on and off, not something an aftermakret unit would understand. In fact the whole information section of the harness isn't used.

XJDano > Kaizer Soze
11/27/2014 at 20:54

I don't know what an aisin aw-55 is. Auto or manual.

Manual would be ok. Auto too if you put it in neutral.

Not sure how the Saab is set up, but I can do it in the metro, but no nannies or drivers assists. Put clutch in cycle key off and then back on, to restart, release clutch similar to pop starting.

DrScientist > Kaizer Soze
11/27/2014 at 22:53

saabs dont have steering locks? amazing. i may need to pick one up just because of that!

hope your vermont holiday has been enjoyable!

Kaizer Soze > DrScientist
11/27/2014 at 23:20

Thanks it has been as good as a family holiday where the family isn't yours can be. Free food and housing and tomorrow I'll be going skiing so that should be good.

And yeah as far as I know any Saab with the key in the middle has no steering lock, it's replaced with a tranny lock. Later ones might have an electronic steering lock though.