Diagnossis of 90BT freezing during boot-up problem

[dmindock]

I have been having trouble with my Pioneer AVIC 90BT locking-up during boot. In order to troubleshoot the problem I tried to recreate the condition which leads to the lock up. I own a new 2009 ford mustang.

 

In the first set of trials I turned on the car with just the battery, then I turned on the car by cranking the engine to see if this would effect the nav systems stability during start-up.

 

I turned on the battery power to the car without cranking the engine 10 times. I waited a minimum of 1 minute between each test The head unit booted up each time without locking-up. No problems found at all.

 

I turned on the car by cranking the engine 10 times. I waited a minimum of 1 minuet between each test. The head unit locked-up 25% of the time.

 

The results indicate that cranking the car engine was in fact related to the head unit locking up.

 

In order to diagnoses the problem further I took the head unit out and took several DC voltage measurements on the power lines. I took 10 test of the power lines when just turning on the car with just the battery and 10 tests while cranking the engine.

 

In the first test, testing the power while just the car battery power was turned on I found that the DC voltage supplied to the head unit was 12.63 volts DC. This was consistent in all 10 tests with a +/- 0.2 variation in voltage.

 

In the second test I examined the power when cranking the engine. I found that the DC power supplied to the head unit starts at 12.63 volts DC, then drops to 10.3 volts DC, then back up to 12.63 volts DC in rapid order.

 

Plugging power and audio back into the unit I examined the start-up routine more closely. When using just battery power the unit boots up by producing a splash screen, then the unit comes online.

 

When cranking the engine, the unit starts the boot-up process, the splash screen comes on, and then the splash screen goes blank, splash screen comes back on, and boot-up either proceeds as normal or locks-up.

 

By my reasoning what is happening is that the voltage is dropping below the required voltage to maintain the unit power and it forcing a restart during the boot sequence. Since the power comes right back up to the minimum required within a second, the unit can latch on to the old boot-up data, gets confused, and locks up.

 

Is anyone else having the same issues.

[dmindock]

The system being testing has no modifications of any kind. No parking brake, not software edits, nothing.

[minifreezer]

when you start the car do you have anything else on like the a/c, headlights, or even the door open. Any of thing else being on while you start the car draws on the battery untill the car is started and the alternator kicks in. Also even though the car is new you could have a faulty starter selonoid drawing more from the battery than needed. Check the voltage at your car battery while someone starts it and see if the voltage at the batter drops to 10vdc also. If it does it could be the selonoid like i mentioned earlier or the starter for your car just draws alot of power. Hope you find a fix for it.

 

I have read somewhere awhile back that someone was haveing a prob with voltage drop to his radio during engine starts and his fix was wiring in a capicitor and zenir diode. Can't remeber the exact wiring, buty basically all it did was once the voltage dropped to below 12vdc the capacitor discharged and kepped the power at the radio above 12vdc. If you do a google search ad find it you will know because the guy posted a wiring diagram and the part numbers of everything you need. Good luck and hope you get this thing fixed.

[minifreezer]

Oh yeah could be something as simple as the battery going bad or not haveing enough cranking amps for your car.

[dumpystig]

Solenoid has nothing to do with current draw, it's simply an electro-mechanical switch and draws a negligible amount of current. The starter, on the other hand, draws a large amount of current, hence the big voltage drop. I think the basic design of the Avic circuitry is flawed: the 500 is even more niggly at start-up, but it's something I've got used to now. Although once booted it's NEVER locked, re-booted or gone into a loop.

[minifreezer]

Solenoid has nothing to do with current draw, it's simply an electro-mechanical switch and draws a negligible amount of current. The starter, on the other hand, draws a large amount of current, hence the big voltage drop. I think the basic design of the Avic circuitry is flawed: the 500 is even more niggly at start-up, but it's something I've got used to now. Although once booted it's NEVER locked, re-booted or gone into a loop.

I agree with you the solenoid should not draw current (granted i have not worked on any newer fords lately) but i have had a starter selnoid on a couple of fords ('85 and a '93 back in the day) cause too much of a current draw. Because of the coil winding in it that gets energized when you turn the key to pull the contact down that connects the battery power to starter was shorted. The ones i had were supposed to ohm out at 50ohm's (i think) and were actually ohming at less than 30 through the coil.

 

Also had one that the contacts in the solenoid were not makeing complete connection creating high resistance thus causing the starter pull more current to start the motor.

 

It is just a suggestion for the person to check, my job is electronics and environmental system on aircraft and have seen some pretty messed up fixes for siminlar probs on aircraft with systems not working when a load is put on the aircraft battery or electrical system.

 

BTW dumpystig i hope you dont take this personal ar anything like that. I have read many threads that you have posted in and i respect you and you surely know your stuff.

[dumpystig]

BTW dumpystig i hope you dont take this personal ar anything like that.

 

LOL not at all mate, we're all trying to do the same thing and help each other if we can

 

But dmindock says he has a '09 Ford, so I doubt very much it would be a fault with the solenoid or starter (altho' new cars DO sometimes come with faults that they shouldn't have).

I think it may be a problem with that particular model of Ford, new ignition/starting/charging systems and electronics are a far cry from cars of just a few years ago. But I still think it's the design of the Avic electronics that's at least a part of the problem. I wonder if anyone else is having the same prob on vehicle start-up........

 

And I think maybe you know just as much as I do, if not more