11lexus350c

hello all,

I have been trying to help a friend of mine out with a parasitic draw on his 2011 350c, and it seems I've really stepped in it this time and have managed to punish myself for trying to help

I made a mistake and popped the main fusible link by shorting out the alternator hot lead by accident...this killed power to the car, I purchased a replacement fusible link from my local lexus dealer and installed it

this is where the problems begin. New fuse installed and I have power inside the vehicle, but its like the car does not recognize the key/fob anymore. Key battery is good (new battery, lights up like normal) but the vehicle doesnt recognize it, nothing happens when the lock and unlock and trunk buttons are pressed on the remote

the green light on the starter button will not light up at all, not green, red, or anything else, I've tried holding the key fob in front of the button, no difference, I'm pretty sure I've double checked all fuses in all fuse blocks and all seem to be ok. I cannot communicate with the vehicle with my scan tool because essentially I cannot turn the ignition on, but the DLC port does have power. Brake lights do work when the brake is pressed so I dont think its the brake light switch. Ive checked the ignition 2 fuse both with a tester and visually and its ok. so now ive got a car at my place that ran before I messed with it and has now been turned into a paper weight

I'm at a loss on what to do next...I can take the fuse block back apart and double check everything. but I took pictures and changed the fuse over one wire at a time.

can anyone think of anything I can do or check next? I'm already out almost 200$ on the fuse, I really can't afford to eat whatever lexus is going to charge me to get this thing running again when all I was trying to do was keep my buddy from having to jump start his car everyday
I appreciate ANY insight anyone can give, anything I can do to avoid a big bill over at the lexus dealer

2013FSport

iTrader: (2)

That had to throw some big @ss sparks... Going back through every event, can you positively state that at no time was the vehicle subjected to battery reverse polarity??

If what you wrote is what happened, I don't see down stream fuses past the main fuse being blown but having never dug into this scenario, I could be wrong. Assuming the car was off, I'd think the alternator *should be okay.
What I have seen with these cars, is abrupt powerless leads to system miscommunication on the CANL CANH lines, and this creates a various issues, one of which we have seen is disassociation of ECM to Immobilizer which I think can be restored by a 30 min handshake routine which can found on you tube.

I encourage you to look through the OEM owners manual at fuse locations and descriptions as the manual has far greater detail on circuits and what they do and are associated with the fuse box cover.

PS before trying any further repairs, double check your work and every fuse by pulling them and testing them.

And sorry, your story sucks.

11lexus350c

Definitely 100% no reverse polarity on the battery or connections or jump pack at any point

I am at the point where I believe the problem is either in the fuse installation or the short caused the disassociation of the ecm to the immobilizer like you mentioned. I'm fairly competent at this sort of stuff I am just not super familiar with this particular car and its immobilizer system. I was a Honda dealer tech for years before my back kept me from spinning wrenches any more. It was a stupid mistake caused by a combination of things, I had the battery disconnected to do some draw testing and wanted to disconnect the alternator and see if the draw went down any, it started raining and I wanted to roll the window back up so I hooked the battery up to do that, forgot about that and then went to put the alternator hot lead back on, no huge sparks, fuse did its job and popped quickly, and it was only a fraction of a second of contact to the body

I cannot seem to find any information on this handshake routine to get things talking to each other again...maybe my research skills are also failing in my old age, can anyone help point me to something relevent? Ive tried searching and all I seem to find are videos about how to start one of these cars when the fob battery is dead

its been almost two weeks at this point, if I cant figure something out soon I am just going to tow it to the dealer and eat the repair cost so he can have his car back, he just got it and I feel terrible hes been without it for this long already

2013FSport

iTrader: (2)

Agree that something is still wrong as the Amber push start light should come up.

What does work with ignition off.
What works with attempt ignition on?
Ignition has to work for this to work, so keep looking for root cause.

Search YouTube but here is one. If this is done place a battery charger on it, if it goes under voltage during this process, no good comes of it.


All of that said, I need to see the whole schematic which I don't have time for atm. If you are good with schematics subscribe to www.alldatadiy.com

Check these out, it may help.

11lexus350c

I cannot turn the ignition on, I get no key missing message, basically its like there is no power to the dash, I can turn on the interior lights, trunk pop button works, I can turn the headlights on, but that's about it. I'm going to double check fuse installation again.

the green backlighting on the engine start button does light up when I open the door, but the indicator light does not light up at all

I borrowed a friends password to alldata and I am going to try and go over the diagrams today. Car still has the parasitic draw too so the battery is dead again since I havent messed with it in a few days

11lexus350c

I just took the fuse block back apart again and double checked my work against the pictures I took before it was taken apart, wires are all bolted to the right spots, nothing missing every connector is fully latched

I'm charging the battery again now, going to go over the diagram that was posted and the diagrams I have from alldata to try and make sense of where I am missing power to get the ignition to turn on

I will admit I would find this whole process much easier if I had an actual key to turn, then at least I would be able to check for voltages with the "key on" rather than trying to figure out why the start button doesn't do anything.

I assume that if the vehicle had lost communication or ID on the key fob I should get some sort of key missing message in the display like the fob battery was dead ?
like I must have another problem I need to find first if the car isnt even telling me it doesnt recognize the key?

2013FSport

iTrader: (2)

Correct. Use that diagram I posted above to find the most likely suspects. I'd guess you are missing a fuse or two. Pull them and ohm them. One cannot successfully test them in the car, they must be removed.

Double check the fuseable links in the plastic cover too.

I'd assume you looked at the ones in the drivers kick panel to?

11lexus350c

yes, checked each fuse in every fuse block I could find both with a power probe and a visual inspection by removing them 1 at a time

I am currently double checking that the fuses are all in the right locations, maybe I put one back one slot out of place or something like that

MikeFig82

iTrader: (13)

I found this online. I'd verify on Techstream or Alldata.

11lexus350c

thank you for the diagram, I was trying to avoid pulling half the interior apart to get to the back of the start button, but I need to attack this from a different angle than I have been. I know some power is getting to the button since the back lighting comes on, and I doubt the button itself is damaged from my screw up, but I guess I have seen stranger things happen

I'm really hoping for an AH HA I'm a dumbass type moment where my mistake jumps out and slaps me in the face, but somehow I doubt I'm that lucky

MikeFig82

iTrader: (13)

Haha. I did more digging online and looks to be a better diagram.



The push start is relatively easy to remove.


https://www.clublexus.com/forums/is-...ispreloading=1

https://www.clublexus.com/forums/is-...r-options.html


GL

11lexus350c

thank you for that link on the button removal, and all the other info you've provided, I really do appreciate it

2013FSport

iTrader: (2)

So what ever happened to this? It seems like another 2IS that won't communicate on CAN bus but still suspect something is being missed.

11lexus350c

I ended up towing it to Lexus. cost me 1k$ had it back in two days

They told me the issue was with an aftermarket component that was getting its source power from the body control modules power and that even though the main fuse had popped the no start no key read problem would have occurred anyway and that the aftermarket component was also the source of the draw. maybe I sped things up popping the fuse, maybe its just bad luck, at least its out of my driveway

So all is well that ends well I suppose. Lexus was super helpful, I don't think it's a bs story, but at the same time I would have like to have been able to talk to the tech that looked at it

2013FSport

iTrader: (2)

What was this $1000 aftermarket part from hell you speak of? Did the owner help you with those expenses?

Saying the part cost you time, $money$, and suffering which sucks...