08 Prius struck by Lightning!

This point in particular is cause for concern, down the road. The car may experience random issues maybe a few months down the road. I've seen it with cell tower BST's

Electronic circuits that initially survive a massive surge will be stressed. Overall, the long-term reliability is compromised

Have you ever been inside a large industrial building utility entrance when lightning zaps the primary? That can be an ... *interesting* experience. Fresh underwear change recommended

I was standing about 20 ft from the transformer pothead during a lightning storm. Suddenly this loud CRACK! came from the pothead and the utility lightning went out, the backups came on

I have healthy respect for lightning. At my hobby farm, I use Rayvoss at the service entrance for strike protection

 

A typical car - Corvette excluded - may not be a perfect Faraday Cage, but it's usually good enough

 

jayman,

It's an interesting point you make there.

Thinking about the push towards ultralight construction and the use of
non-metal structures. I take it it would matter --lightning wise -- if there
was an included metal roll cage, passenger safety zone, whatever.

Would the passage of lightning through such a structure create temps
high enough to set the thermo-plastics afire?

 

I'm no electramajiggy expert, but I think "Faraday Cage" is specific to static charges, and therefore not applicable to lightning strikes. "Skin Effect" on the other hand is what protects the occupants of a metal cage.

At the Boston Museum of Science they have a huge Van de Graaf generator (actually built by Dr. Van de Graaf) with a metal cage that's raised up on a pneumatic shaft. The occupant of the cage can actually touch the metal while it's being hit with arcs from the generator and not get shocked. If they reach through the bars and touch the outside of the metal, ouch! I'd guess for this reason that most of the current going into this car went around the car into the ground, and only a small portion went into frying electronics.

At the museum, they can ensure that arcs strike the same spot on the cage by putting a tiny metal clip on one of the bars... I guess lighting likes pointy protrusions, sort of like this car's antenna. I wonder if that's the case with most car-lightning encounters.

 

Lightning -can and does- start fires, but most plastics will not continue to burn without external energy, especially the ones being currently used in composite structures. Keep in mind, most lightning caused fires happen when the lightning jumps through the air (or wood etc) between metal structures. Which is why the codes for lightning protection require all metal parts of structures be bonded together. For example, in my house, the lightning protection cables are bonded to both the electrical system ground and the water pipes, even though the lightning protection system has its' own ground rods. They even bonded the eve troughs, gas chimney, and turbine attic vent to the main ground cable.

"Pointy bits" tend to concentrate the electric field in the air, which makes it easier for the lightning leader to travel to them. Note that they also concentrate the current in less metal, so can be more susceptible to actually melting at the tip when struck. I've had to replace several "air terminals" and radio site antennas due to this.

 

Hi Bear68,

I went thru all seven pages of this thread but you did not give any specifics or technical troubleshooting methodology on your findings...can you help me out and guide me "technically" in the right direction?

Thanks!

 

The disadvantage of using the CAN bus, is that it is electrically a "bus", so any one device on the bus can actually take down the whole bus!

Much like back in the days of 10-Base2 Ethernet.

What I would do is isolate each ECU from the bus and add the termination resistors if needed, then use the scantool to query each one, or at least look for CAN activity. When you find the one that's not talking, that one is dead.

It's possible that one bad unit would make it appear that the others were also bad unless you perform this method of troubleshooting.

If anyone ever finds another bad ECU from lightning, I would love to perform an internal diagnosis on it and see what really happened. It could be as simple as a fried CAN transceiver, which is an easy repair.

If it hits the antenna, then it's likely going to take out the front end of the radio at least. If strong enough, it could also leave the radio and head into other nearby devices, so the failure could be like "dominoes".

 

Hey Bear68,

So the gateway ECU is first eh? My lightning struck 09 Prius had the antennae shorted to ground and has hence be removed. I am able to restore power back to the Dome fuse. The radio does not turn on and I am unable to communicate with an ODBII reader, plus the ABS Main 10A fuse keeps blowing and the brake tail lights keeps coming on and does not turn off (I put in a 30A fuse and it stays on...just for quick troubleshooting).

At this point my next step is to replace the gateway ECU and see if I can't get the OBDII scanner to communicate.

My main question is: Is there a theory of operation in which someone has detailed in regards to the starting of the car? For example -- When you first press the power button ECU A scans for all these parameters to be in place, if it's missing input from brake...X happens and shuts down ECU A...etc....etc....etc...

I would like to know the detailed sequence that occurs in a normal Prius when you press the power button that way I can say OK this is not happening on my lightening struck car and troubleshoot that.

Thanks for your input.

 

Thats why i have a shark fin antenna.

 

Do not start randomly replacing ECU's! Expensive! I would check for proper power on each ECU on all it's various power pins, then check it's CAN bus. You should see 0-5v signal pulses on each modules CAN pins if it's still "alive". When you find a dead one, then you can confirm it by directly hooking a scantool directly to it with a 60 ohm resistor across the bus. Then and only then would I consider replacement.

 

Are there schematics on the ECU's? Will the electrical wiring show detailed schematics on power pins and I/O pins?

And how do you "directly" hook a scantool to the said ECU?

 

You do have the wiring diagrams and service manual right? You can subscribe on the TechStream site for a day and download them all for not much money. I've heard there is a torrent available as well if you would rather go that way. You will want the '06 package, as they are the same for your '08.

The wiring diagrams are limited to the car's wiring, and they aren't that good, but they do have all the pinouts and you can determine how everything is connected. There are no schematics of the internals available anywhere. (inside of an ECU, etc.)

The easiest and least invasive way to isolate an ECU from the bus is to pull the black/white wires. There are plenty of posts on how to get the pins out non-destructively, so I won't bother rehashing that.

Once you have the pins out, make sure they don't short (tape them), and use a few paper clips to poke in the holes where the pins were. I soldered two 120 ohm resistors across the paperclips (parallel) to provide the termination, but you could also do it with a few extra alligator clips. If you omit the termination, this trick may not work and you might assume the ECU is dead when it's not!

Connect the 2 alligator clips up to the CAN-L and CAN-H paperclips and run them to pins 14 and 6 respectively on the OBD2 scantool cable. You will also have to provide ground on pins 4 & 5, and finally +12 on pin 16.



This diagram shows the OBD2 *cable* end view, so pin 16 (+12) is on the lower left.

Once you make all these connections, fire up the car in ON mode and verify that +12v is on all the pins it should be on. You should then be able to query the ECU in question directly with TechStream.

If that works, then you know the ECU is at least 90% good, and it's not taking out the whole CAN bus. I bet you will find one ECU somewhere that's fried and it's CAN transceiver is shorted thus preventing any of the ECU's from talking properly.

The other thing you could do is simply disconnect CAN-L/CAN-H on each ECU one at a time until you get a response with TechStream. This isn't as conclusive, but may be faster if you don't feel like going through all the steps I outlined above.

 

Here's how the networks are interconnected:



Note that all the critical systems are on the CAN bus. The Gateway ECU only links the non-critical systems, so if they are actually powering up correctly, then you only care (at least initially) about the CAN bus. Once you get the car running, if you find the other systems are not working you can troubleshoot them at your leisure.

However, the Gateway ECU, just like any other on the CAN bus can prevent the car from running, so don't count it out!

 

Is the OBDII connector on the CAN bus somehow? Does it have its own CAN transceiver?

 

The OBD2 connector (properly; the DLC connector) is directly connected to the CAN bus as you can see form the pinout above. All the major data busses also are.

There is no transceiver, that would be in the scantool itself.

 

pEEf,

u say u can query directly with TechStream...what exactly do u mean by that? What is TechStream? Is it a service? A protocol? Or are you talking about the OBDII scanner?

 

Techstream is Toyota's scantool system. You need a passthrough interface, like the Tactrix OpenPort 2.0 or the Drew Mongoose, then a copy of the windows Techstream software. It can be downloaded form the TIS website.

There is little chance of you repairing that car w/o this toolset. You won't even be able to clear all the codes, let alone replace many of the ECU's if needed, as they must be "married" using Techstream.

 

Can someone please tell me where the DLC is on the '08 Prius?