YAIQ - Yet Another Immobilizer Question
 

Hi, I just bought a 2002 Boxster w/5 speed. It drove fine during the test drive, but the owner said there was a fuse or relay problem opening the hood & trunk, and windows. I probably should have known it couldn't be that easy.

So I drive it close to home, make a stop, then come back out and can't start the car. Electrics come on, no starter/click, etc. I can operate lights, convertible power top, etc so the battery is fine. The key fob lights up, but won't unlock/lock the car. The interior switches won't unlock the trunk/hood. The hood manual release cable won't budge.

I was able to push-start the car, get it running, and drive it home. Still can't start it. It appears to be the immobilizer from what I've read. Oddly, it appears that it has already been replaced, and the replacement is in the waterproof box from ECU repair in Ft. Lauderdale. I'm waiting to hear back from them, though they did respond to say their warranty doesn't apply once the car is sold.

My real question is if it's bad, what do I do? Can I buy a matched ECU/IMMOB/Keys set from eBay or elsewhere? Can I just replace the immobilizer?

Here are all the symptoms. Thanks for reading this long post.

Symptoms:

• The car was starting when I test drove it, though on one attempt it didn't; all the lights came on and acted normally otherwise.
• The owner told me the windows weren't working and they couldn't get into the trunk, but it was "likely just a fuse or relay".
• I tried to energize the system with the slide-out positive lead in the fuse-box as the manual says, but no change.
• The key fob blinks red when the buttons are pressed, but doesn't do anything.
• The power windows and stereo won't turn on. The radio backlight does come on.
• I checked every fuse and replaced a few just in case, but no change.
• The front and rear trunks won't open at the switches. The manual release for the front trunk won't budge. I haven't tried the rear trunk.
• I was able to push start the car when I was bringing it home and had stopped at the grocery store on the way home. It wouldn't start once I got back to the car. Battery seems fine, I can lower and raise the convertible top.

Sounds like a bad starter.

Even with the non-functional windows and hood/trunk switches and the fob that's not doing anything?

Not likely.

Pull the immobilizer and have a look. You really need to get the front trunk open first so you can disconnect the battery (if you absolutely can't get to the battery, at least pull fuse C3).
Most likely have corroded connectors on the immobilizer (immobilizer replaced, but they never cleaned the connectors...happens a lot).

Check

1. Inmobilizer fuse
2. Check the clutch ignition switch..bihind clutch pedal
3. Check the ignition switch
4. Check ignition relay in rear trunk

Thanks, I will try that. I have been trying to get to the front latch from the bottom but haven't gotten far. I tried the jumper post in the fuse box but that didn't allow anything to open.

Thank you.
1) Fuse is okay.
2) I will check the clutch switch. Can you just jump the terminals to close the circuit for the test?
3) I have a replacement coming in, will try to test it, though. Other things that rely on the acc position work (ie. the top)
4) Can't get there yet, but I want to check that.

"... their warranty doesn't apply once the car is sold."

Glad I saw that, and clarified upon their website.

No bueno.

Check around inside the car for water intrusion given where you are.

How to get that front trunk open? Several ways.

If it were me, I'd probably start by changing the ignition switch just to rule that out. A myriad of problems can arise if that is going bad...

Next I'd have a look at the waterproof immobilizer case under the drivers seat. I just installed one in my car last month, and although it wasn't a hard thing to install, the fact that the previous owner(s) changed the immobilizer means that those (large black and white) connectors also saw water. They could be corroded. If the connectors still had water in them when they were sealed inside the waterproof box, they could have continued to corrode after it was sealed up. Also, it's possible that whoever installed the waterproof case didn't do a good job sealing up the wiring harnesses. You really have to work the silicone adhesive into the wire bundles to get it to seal properly.

The top cover of the waterproof case is sealed with a bead of clear silicone sealer all the way around. It might not be the easiest thing to get off.

Hang in there - I'm sure you'll get it all sorted out!

Agreed. They responded with that and a question about the symptoms, but going on the 2nd day without a response. Not the way to earn MY business...

Will do that in the morning and thank you for the reference link.

Thank you! I took a brief look at it and there seems to be something vasoline on it. I don't think these people knew what they were doing. I suspect you're right in all ways that it wasn't installed properly.

Well, I pulled the seat out and popped open the waterproof case. I don't think they sealed it correctly, plus the silicone that should have hardened was soft everywhere but right around the cable bundles. The strangest thing was that the whole board was wrapped in a ziploc bag, with wire ties tight around the two cable bundles coming in. There wasn't any water in the case, though. The board itself has issues. The connector for the fuse cable came apart as I moved the connector around. It appeared to be loose when I opened it up. There are also some possibly damaged chip leads on the board. Definitely not in good shape. So now to send to the original repair company or find a better one.

Has anyone ever bought a set (ECU/Immobilizer/Key Fobs with RFID pills) used from a donor car? Is that feasible?

Sounds like a botched job of installing the waterproof case, and on top of that, putting the case around a damaged board...

I would contact Qmulus on this board about getting that board repaired. If you'd rather swap everything out, give Woody (ItsNotaNova) a call...

That fuse connector is kinda flimsy. When I went to plug in the fuse extension cable on mine it bent the connector straight up (too many muscles! LOL) I bent it back down, and no real damaged, but it's definitely not real sturdy...

Here's a photo of the sealer that comes with the kit from ECU Doctors:

http://986forum.com/forums/uploads02...1523589298.jpg

And here's a link to the video on how it *should* have been installed:

https://www.youtube.com/watch?v=vIhf9j0jHlM

Hope this helps...

+1 on the ignition switch. You cannot push start the car if the immobilizer isn't responding, the ecu will not fire the injectors.

To double check short the start lock relay in the rear trunk. Relay #7 bottom left.

This will allow the car to crank without the immobilizer signal, if the car cranks and fires, its likely that relay gone bad. If the car cranks and doesn't fire, its the immo. If nothing changes, ts the ignition switch.

The strange thing is that some of the silicone in the box openings looked right and had hardened, but all the other stuff, including around the perimeter, was like vaseline.

The board itself shows damage. Thank you for the contact info!

I did change out the switch, but had already pulled the immobilizer to look at it. The person who put it in wrapped the board in a plastic bag and then tried to seal the cable bundles with tie wraps and more silicone, or actually something that didn't cure.

Nothing was wet but there are broken connections on the board.

I would have like to have tried your troubleshooting before I messed with the immobilizer, though from what I found, I don't know how that would have gone. I get what you say about the fuel cutoff. Now I'm confused.

Should have updated this a while ago, but I had the ECU replaced and matched to the DME and keys. Then I found I had a dozen wires melted in the cabin, so I patched replacements into the harness and everything is working again. Now onto the fuel sender and expansion valve. And replacement top...etc.