Engine off coasting on my matrix
 

I want to be able to coast with the engine off but leave the ECU, dash, & scangauge on.

From my searching it looks like what I need to do is make a kill switch for my fuel injectors. I went digging through my low voltage scrap wire box and found a 12v 40A relay that came off a HID kit. It is designed as a normally open circuit but I think I can make that work bu using a normally closed momentary switch.

My issue is finding the Injector fuse, any idea as to which one that might be on a 2006 Matrix?

All I saw in the fuse box that might be it was a 20A EFI fuse and a corresponding EFI relay. No hint as to what EFI stands for.

Ideas?
Hints?

Yeah, that dash reboots slooow...

EFI is electronic fuel injection, but that circuit seems to contain a lot of stuff normally, likely the computer that controls all the dash stuff.

The dash does boot slowly.

There is a EFI 2 (15A) and and EFI (20A). Which one does what?

Take the fuse out and see if the car starts.

that might work, but it will not tell me what else is on the circuit.

I did some searching for wiring diagrams. I found one for a 2003 matrix, my 06 should be similar but not exactly the same.

Anyone want to read these and give me a none EE description?
What does the EFI fuse do?

If these do not help I have 20 other pdf to sort through.

Page 1
http://i835.photobucket.com/albums/z...3at71530PM.jpg

Page 2+3
http://i835.photobucket.com/albums/z...3at71534PM.jpg

4+5
http://i835.photobucket.com/albums/z...3at71543PM.jpg

6+7
http://i835.photobucket.com/albums/z...3at71547PM.jpg

8+9
http://i835.photobucket.com/albums/z...3at71554PM.jpg

Thanks!

Don't they come back online when you turn the key back into its normal driving position (II) ?

If I put it back to II too fast, even the engine will come back on !

Dash does but I do not like power cycling the ECU. I do not think that the SC comes back on (or it takes a while).

All I do with my Vibe is to stick it in Neutral, turn the engine off with the key, wait a few sec's turn the engine power back on with out hitting the starter and coast. This way I still have power steering while coasting, then bump start it when it necessary. My ScanGauge is in Hybrid mode so that stays on, car will coast quite a way.

Neddy

I will have to try this on one of my mile long coasts and see what happens, it has been a while since I tried this.

The odometer is off while you have the key off (and possibly a few seconds after you key back on). During this time you are not logging distance and throwing off your only means of calculating mpg. A kill switch is preferred since it avoids this.

Bingo
Daox- did you rig one up for your matrix? Do you know how on that car?

Unless the Matrix has electric power steering, you won't have power steering unless the motor is spinning. Not moving the key to Off is important though, as most cars will engage the steering lock in this position.

Nah, I didn't do much EOC on the Matrix. Most of my driving was P&G with the engine on (which led to me never hitting 50 mpg :().

Unfortunately, your pics are too make sense of the diagram.

Loosing power steering is not a big deal to me.
Locking the column if I were to turn the key one spot to far is very dangerous. So I want a kill switch.

Daox: the diagram is messy but it is all I could find. I am looking at what the EFI circut does.

Those wiring diagrams look like the ones I used to find the injector wire in my Scion xA, your Matrix's little sibling. Do you also have a PDF that lists connector locations? If you can send both of those to me, I got pretty good at reading them and can tell you exactly what wire to cut at what location to cutoff your injectors.

Regarding the relay - does it have 5 connections? I would not use a normally-open relay just because if it fails it will fail in a way that leaves you stranded. What you want to do is interrupt the power side of the injectors (not the ECU side, which gets grounded to shoot gas). Since you're tying into an always-hot line, you can also use that as your power feed for the relay. Then all you have to do is ground the other end of the relay coil and you open the relay.

(Wandered away from my first question there - a 5-prong relay normally has two lines for the coil (nonpolarized), a common connection, and an NC and NO plug).

Look at my other posts and you will see the mod I did for my xA.

Here is the link for the connection diagram (was to large to upload here so I put it on my gmail):
https://docs.google.com/fileview?id=...thkey=CO-gwPcH

and the wiring diagram as a pdf:
https://docs.google.com/fileview?id=...thkey=CPqT4oQH

there are about 20 more small pdf's with more EE stuff, I can try to find more if you need it.

Thanks!

It looks like all of your injectors splice together at junction l12.

http://ecomodder.com/forum/attachmen...1&d=1287086676


And junction l12 is here:

http://ecomodder.com/forum/attachmen...1&d=1287086678

So, I should put the kill switch in at junction 12? what voltage is running there? would I still use the same relay setup as with the fuse or would I need to set it up differentially?

The injectors run at 12V. Make sure you splice into the wire after the injectors are all spliced together. It might be easier to do this outside of junction 12.

I'd highly suggest getting either a normally closed switch or NC relay. Theres no real need for a relay, although if a NC relay fails or your switch fails you likely won't have a problem. So, it does provide a little extra fail safety. I wouldn't mess around using an NO relay/switch.

What amp rated switch will I need for that job? I like the idea of a NC switch. I was planning to make my splice a few inches out from the connector presuming I can find the right one. Any idea how to find that connection from the others in the area?

Don't junctions happen inside wire bundles? I could not figure out how they worked in my xA.

There is another option - the single black wire/white stripe coming from the ignition switch goes through pin 8 of connector IG1. This is located in the same place as the splice - it's a 10 pin connector with two large central pins - one of those is #8. The male/female end connectors can be seen on page 8 of the connector diagram. You should be able to get to it by popping out the glove box.

so option #2 is put a NC switch in line with the black/white pin 8 wire? What else will this kill? would it not be the same as turning the switch?

No, the only thing that is connected at the #8 pin is the keyswitch to the injectors. Nothing else will be killed.

Also, if you decide on the relay, here's how to wire it. You can run a very light gauge of wire from the relay to your switch (and then ground). I also used a male and female disconnect to hook to the relay I used, so that I can pull it out and plug them back together if I take it back to the Toyota dealer.

Niner: thanks for the ideas :)

I like the idea of making it non noticeable at the dealer, I will have to take my car in some time in the next few months to get a free ECU replacement (recall). I think I will get enough flack about my car without the kill switch. Taking it back to stock (as far as the kill switch) in the parking lot is a big +.

Why bother with the relay though? That wire looks to be low current as it is tripping a relay itself. All I would need to do is to find that wire, add a NC switch and route it back to the splice point. If I hide the splice the dealer should never see it :)

I think you're following the wrong black/white wire. From the ignition switch going right, take the upper black/white wire. That goes through a little square box labeled 8(IG1) and then breaks into 4 wires (passing through octogons that represent junctions), and then into devices that look like little coils (the injectors), and then into the ECU.

The boxes that also hook into the other black/white wire are the spark ignitors. Those do have an internal relay, so they will be pretty low power, but you'd still be spraying gas into the engine until the ECU figured something was wrong.

However, you could use a normally closed switch for the injectors. They're not terribly high current - the wire appeared to be 16 or 18 GA, but current across that wire could go up to a few amps. I'm using a microswitch that's rated in hundreds of milliamps because I couldn't find an NC switch at the local Radio Shack above 1 amp. Of course, if you order online, finding something the right size or oversized should be easy.

Thanks for the correction I was looking at the wrong wire. We are still talking about cutting the injectors just past the I12 junction. I will have to go looking for switches, might an auto parts store have a better selection? What amp rating should I get? Would a 10A be enough for a direct splice?

How big is your micro switch? I like the mount point and might use it if I can find a switch to fit :)

I was talking about the#8 pin on the IG1 connector (plug and socket inline in the wire), Daox was talking about the I12 junction, which is nearby but I think actually is within the wire loom. Either way, it's the same single wire.

10 amps should be enough. I am running a 10 amp relay because it was cheaper than the standard 30 or 40 amp auto relay. Looking online, it seems like most stock injectors are "high impedence", around 12 or more ohms, so 1 amp - so I would be comfortable with 3 amp rated switches. I looked at Autozone and found even less good switches - just large toggle switches and a few momentary-on switches. Nothing at all was normally closed.

The microswitch I got at Radio Shack in a 4-pack (I possibly plan on using the other three to place dash buttons for my MPGuino, which is far back on the dash). The size of the little box is 6mm x 6mm x 4mm, with a button that is 6mm high and 3mm diameter. There are 4 little legs on the bottom, each about 2mm long. If you get something similar, make sure to check with a multimeter which pairs are connected and which are open - it was not the way I expected. It looks like of like a squashed animal (legs out to the side) so I guessed that it was either two switches, left to right, or two contacts for one switch, left to right. It ended up being two contacts for one switch that connected front legs to back legs.

I will have to go shopping for more modding supplys :)

After some reading I think I understand how to hook this up!
If I do it with a NC relay, I would only need a NO momentary switch right?

I like the little bump switch on the stick. How did you attach it? Any more picts then here:
http://ecomodder.com/forum/showthrea...-xa-14767.html

No more pics, but there's not much more to show.

When I pulled the shifter off the car, I saw that the lower part had a good sized gap between the cover and the actual shifter rod. I drilled a hole well oversized for the button, and then took a Dremel and shaved a groove to help hold the base of the button (the sidewall was a little too thick for the button to reach through).

To make the button, I got some perforated board at Radio Shack - it's got a regular grid of holes and copper rings around each hole. I soldered the 4 corners of the button to a 1/2" x 3/4" scrap, and then pushed the wires through the backside of the right two holes and soldered them to the contacts. I put the button in place, mixed up a little epoxy, and glued it down. Afterwords, I also stuck a little electrical tape to prevent any shorts from the rod, since shorting to ground would kill my engine.

The way the shifter is mounted goes like this: there is the rod, and a plastic clip set in a groove on the rod. The shift boot has a ring that sits on top of that clip, and the shifter top screws down until it's clamping the boot against the clip. What I did was pull the boot away from the center console, broke a little bit off the clip, and put a hole in the boot so that as I spun the shifter cover on, all three pieces could spin around with the wire. Then once the shifter was where I wanted it, I attached the wire to my lead coming from the relay, and put a screw into the floor for the other side of the switch. Then clip the boot back onto the console, and you're done.

My shifter is just like yours, I might have to try it once I get the switch and relay.

Update:

I went shopping and got the same switches that Niner got :)
My issue is the those switches are only ratted for 50mA so it will not run a 30A relay. I bought a second relay that is good for 10A @ 120vac/24VDC. The guy at radio shack that it is good for 5A @12vdc. Is this right?

Do I need to have this small relay run the big one? or is 5A good enough for the injector circuit?

Well I had it all hooked up and tested it. The car cranked and cranked.... I hit the button and it ran, when I let up it shut off. Opps! I hooked my secondary relay up wrong, I had the NC contact hooked to the ground, so I was grounding out the main relay all the time. When I went to fix it I broke a pin off my relay :( so the project will have to wait until I can get another one.

I will upload some pic later so you can see what I did.

You were right on which wire to snip :)

Hm, I don't see why that other relay wouldn't work. I would think it should be good for 10A at any voltage below 120 volts. Voltage would cap out due to where you start getting arcing, but current is current - 10A at 24V DC looks the same as 10A at 12DC, or 5DC - because the switch doesn't have a voltage drop across it anyways, unless it's open.

Does your original relay say what the coil resistance is? I found one on Radio Shack that was 30A, and listed 160mA for the coil, but also 400 ohms, so at 15V (the high end in a car) it's still only pulling 37mA. Maybe startup/drop currents because it's not resistive?

Sorry to hear about your relay! I hate when stuff breaks. Did you get one of the ones from Radio Shack with wire pins instead of the flat auto connectors? That's what I used, which is also why I had breadboard - I soldered the relay to a little board, soldered my wires onto that, and then wrapped it in tape.

I came up with an idea for a kill switch that would use this same relay - between the switch and the relay, tap in a second line. Attach this second line into a toggle switch, and from the toggle switch into the normally-open side of a second relay, and then into ground. Power the normally-open relay with the starter signal. During normal driving, this relay won't be powered and the second relay will stay open, so even if you bump the switch you don't kill the engine. However, if you flip the switch off when you leave the car, it's harder to hotwire - the starter signal will also kick the second relay on, which will ground out the first relay, interrupting power to the injectors. Fortunately, theft is not a big issue in backwoods Michigan, so I'll probably never try this.

I got the same relay you did- with pins rather then spades :(
I do not have any bread boards to attach it to.

My big relay does not list anything as to specs.

Once I buy another relay I might just use it rather then mess with two relays.
What should I buy at the shack in addition to a relay?

How comfortable are you with soldering?

If very, then I'd get the same little 5A blue relay and a board - the one I got was called a "dual mini board", it was about 3" x 1.5" and could be snapped in two. Each hole has a little copper around it but nothing is connected. You just stick the relay through the holes, solder from the backside, and then it's easy to solder stuff to it from there.

If not, I'd just get the 30A auto relay that they sell. It will probably work with that button.

I have a 30A auto relay, that was my" big one". I was going to hook that to the button but thecurrent of the relay is like 120mA. The switch can only do 50mA.

I can sodder relitivly well. If the board has rings then I. Should be good. I presum I can get that at the shack? Did you get some screw down terminals as well?

Thanks for all the help!

I did, but that was before I thought of using quick disconnects. My first plan was to keep a butt connector in the car if I needed to patch the lines together. With disconnects, I would just solder stubs (or however long you want to move the relay) of wire direct to the board.

Update:
Picts of OEM:

glove box removed:
http://i835.photobucket.com/albums/z...-08-08_938.jpg

Junction in car:
http://i835.photobucket.com/albums/z...-08-16_772.jpg

Shifter nob
front side:
http://i835.photobucket.com/albums/z...-55-31_276.jpg

epoxied in place
http://i835.photobucket.com/albums/z...-55-49_412.jpg

http://i835.photobucket.com/albums/z...-55-56_241.jpg

I went back into town and got the needed supply's.
I got another relay $4.99
A small circuit board $2.99
Some screw down contacts $1.99 for a 4 pack.
Total cost ~$20 (more if you mess up)

It was significantly faster to work with a circuit board then without one.
I soldered the screw contacts to the pins on the relay (with wire):
http://i835.photobucket.com/albums/z...1-21-26_62.jpg

from the top:
http://i835.photobucket.com/albums/z...-20-49_163.jpg

Then I added a termal so that I did not need to splice the ground wires to each other (miss match in size):
http://i835.photobucket.com/albums/z...-33-21_289.jpg

Installed and tested:
http://i835.photobucket.com/albums/z...-43-00_258.jpg

I put in plugs so that I can put it back to OEM if desired. I can also undo one plug and the car will not start :)

Thanks Niner for the idea of where to put the switch and how to rig up the wiring :) It helps me to be able to bounce ideas off people.

Update:
I took it into town today, it works great. The only issue is that the ScanGauge is still turning off after about 20 sec. If I touch the home button then go to gauge it is still showing my MPG (over 700MPG). I want it to stay on.

How do I fix this?