Yet Another Guino Help Thread

[i_am_socket]

Finally got my Guino installed:



Handy little spot there with the change tray I wasn't using.

And the phone box is in the glove box (for easy reach to the ECU and it's accessible without being kickable.



Anyway, aside from needing to find a better power cable to tap, I need to troubleshoot a little bit. I had the same issue as someone else with the crossover RJ-11 cable which was real simple to work out (I looked at the wires in the cable ahead of time) so I have working power when the car is on.

The ECU pinout had the 12 volt wire right, it just lied about being on "always". Its only on if the key is set to "power" and shuts off when starting the engine. At least it keeps the settings data, but I need a truly "always on" power source.

The next problem seems to be with the Injector and VSS wires. I need to get my multimeter in there to make sure I'm getting something out of them. I connected the wires reverse to the directions like the power and ground, but I'm not getting GPH data while parked and idling (I haven't driven around yet, that's next). I figured I got the wires wrong so I swapped the VSS and Injector wires, but then the Guino wouldn't turn on at all.

Has that happened to anyone else? I forget if there is a way to see raw data coming in like pulses per second or somesuch for each data line?

[McTimson]

For the power, you can try tapping into one of the radio's power lines. There's usually one constant +12V line, and one accessory +12v line, which is only on when the key is in the ACC position. It sounds like you're already tapped into another ACC line. For most Toyota's, the +12V constant line is blue with a yellow stripe.

For the other problem - try just connecting one wire at a time. Start with the injector signal, there's a screen that will tell you the GPH (gallons per hour), and if the injector signal is hooked up correctly, it will give you a reading there.

[i_am_socket]

I'll try the one-wire-at-a-time thing. That should probably give me some info.

Next: I tried actually driving and the Guino turned off as soon as I moved the car far enough to get a VSS pulse. I stopped moving and after a second or two the Guino turned itself back on. Strange.

I checked the connections with my multimeter and it looks kinda like it should. Power is steady 12-13v. Injector is wiggling at 12-13v while idle (makes sense since ECU data says 20v/pulse). VSS is actually solid 4.5v while not moving. I'm going to kidnap someone on Monday to check VSS while moving.

Any thoughts on the Guino turning off once the VSS starts pulsing?

[McTimson]

Does the screen look normal when it's connected to the car? If the screen looks weird, like way too bright, then the voltage regulator is probably on backwards.

Otherwise, the Zener diodes could be on backwards, or just messed up. The VSS and injectors are both connected to a zener diode, and if they're not working properly, then it'll mess stuff up.

[i_am_socket]

The screen looks normal so it's not the voltage regulator then.

I installed everything directionally like the instructions said to, but I'll check.

[i_am_socket]

OK, after some further testing, I totally screwed up the Injector connection. How do I know this? Besides the logic of failing to follow the simple directions "connect on the ground side," I plugged it in this morning on the way to work and my engine started running like it had a seizure. The GPH data finally showed up, but was showing anywhere between .11 and .01 GPH while at a steady 1,000 RPM.

Yeah.... tapping into the wrong side of that line was shorting the injector so it was firing randomly. So, I'm going to disconnect that wire so I can test the VSS line because I'm guessing that the Injector line was fudging the whole thing up.

Since there's at least 2 wires that need to be changed now, any suggestions on how to remove the clamp taps? (kinda glad I didn't solder now) Also, any suggestions on running wires from the engine bay back to the cabin? Doesn't seem possible to get the ground side of the injector from the ECU.

*edit* - I double checked the components and they're all directionally correct.

[i_am_socket]

I made a serious OOPS and forgot to follow rule #1 of electronics: disconnect the power first.

I checked the 12v source to ground with the car off completely and it had power, so it wasn't an ACC line. Great, so I just mistakenly swapped the wires now I'll swap them back!

One blue spark later and now there's no power on that 12v line and my car won't start. Did I just fry my ECU?

[Nevyn]

Hopefully you just flipped an auto-reset breaker. Disconnect battery for an hour and try again?

[Intrigued]

Originally Posted by i_am_socket

One blue spark later and now there's no power on that 12v line and my car won't start. Did I just fry my ECU?

Ouch. Grounding a hot wire of an ECU system can't be good. Hopefully the thing was protected well enough that you just blew a fuse somewhere. There's often two or three different fuses that drive different parts of the ECU.

Check ALL of your fuses - key on - and keep your fingers crossed...

[wagonman76]

Originally Posted by i_am_socket

I made a serious OOPS and forgot to follow rule #1 of electronics: disconnect the power first.

I checked the 12v source to ground with the car off completely and it had power, so it wasn't an ACC line. Great, so I just mistakenly swapped the wires now I'll swap them back!

One blue spark later and now there's no power on that 12v line and my car won't start. Did I just fry my ECU?

Good now I dont feel so bad. I just did the same thing on the 6000 wagon when I installed the guino a little while ago. First thing I did was install the wires before the snow came. I didnt disconnect the power, but I am always careful and keep any hot wire bent away and taped off and keep it from shorting against anything. Kept it that way for weeks till I got it done.

Then when I went to install the guino, I trimmed all the wires the same length. At the same time. Stupid me, it didnt occur to me that the wire cutters would bridge all 4 wires and short something out. It must have burned some fusible link because it didnt blow any fuse. So I bridged it into the constant power at the radio. Thankfully its been running fine ever since. Next summer Ill probably figure out what blew and fix it right.