Code 51 last night

[SP 7M]

So there I was (one of those stories) driving along last night killing time until I had to go pick my wife up from class. I was cruising at 45-ish and I had the check engine light come on and the darn thing did not respond to my foot being on the gas pedal. I coasted over to the right and when I pushed in the clutch to stop the engine shut off.

I took a look around under the hood and realized that my EFI fuse was fried-deep fried. I think I had a 30 in there (it was unreadable, but kind of looked green) instead of a 15, which I realize isn't a good practice. I had to switch a couple in the past and forgot to change it back to a 15. I had a new pack of 25s amongst the random gear in the back of my car, so I replaced it. No joy on the start up, though.

So being the slick dude that I am, I had all my tools, TSRM and a little bit of other random gear-as mentioned previously-in the back of my car, to include a piece of wire-bingo. Code 51 it was. I don't remember everything that the TSRM listed that it could've been.

After I disconnected the battery once the car ran and I got a whole 1/4 mile down the road until the same thing happened, minus the fried fuse. I took another look around under the hood. I checked the EFI wiring, which I'd like to re-do anyway, TPS and other wiring and such and saw no problems. Just for the hell of it I disconnected the battery again and it ran. *Sidenote-I had my good buddy Vinnie pick up my wife and bring her my way, so I had a little time to work with.* I let it idle for nearly ten minutes and it seemed OK.

I decided to take a chance and drive back to my apartment and good ol' Vince rode back (on his R6) behind me just in case I needed help during the trip back. I made it back but now I want to figure out what caused that. I refuse to just keep driving it after something like that.

What I'd like to do is remove my S-AFC (it caused a code 24 a while ago), rewire my injectors, get a voltmeter and do all of the testing that the TSRM suggests and see if I come to a conclusion from there.

If any of you would like to take a stab at this, please be my guest. Input is very much appreciated.

This may delay the posting of my pictures, so please remain patient on those.

Yes, this thread is also on www.thesupraforums.com.

 

[Nick M]

Seems like the definition is incorrect voltage with the idle contacts closed. Most TPS's that go bad get a spot worn on the potentiometer.

 

[SP 7M]

Thanks Nick. That's some language that is just past my full comprehension, but maybe as I look into it more I will understand it. The TPS is one that was an extra a former friend had sitting around. The original one wasn't necessarily bad, but replaced just to see if that might have helped the problems I was having. There were a few other fix-ups in and around that area, also.

 

[shaeff]

Code 51

Switch Signal
Diagnosis
No "IDL" signal, "NSW" signal or "A/C" signal to ECU, during diagnosis check.
Trouble Area
A/C switch circuit
A/C switch
A/C amplifier
Throttle position sensor circuit
Throttle position sensor
ECU

Thanks Nick. That's some language that is just past my full comprehension, but maybe as I look into it more I will understand it. The TPS is one that was an extra a former friend had sitting around. The original one wasn't necessarily bad, but replaced just to see if that might have helped the problems I was having. There were a few other fix-ups in and around that area, also.

basically, nick means there's a dead spot on your TPS, causing an incorrect voltage reading to the ECU, which is causing your error code.

-shaeff

 

[SP 7M]

All right, thanks Shaeff. I think I'm going to borrow a volt meter today to make sure all the electricals are giving the proper power.

 

[SP 7M]

*Update* Add a code 14 to that. Lets just say my Supra rode home on a flatbed tonight. I refuse to get mad and curse the car, though, as so many do. I know that none of these problems would have arisen if it hadn't been for my itch to upgrade it.

So I've got a buddy that works in aviation electronics-aka avionics-that is going to do his thing with my ECU wiring later this week. Once goes through there and makes everything nice and secure I will at least be able to eliminate loose wiring there being the cause. I'm sure I can get ahold of a volt meter by then, too, so we can check to make sure everything is putting out the proper voltage.

I hate...excuse me...loathe electrical sh*t. I can't stand working on that stuff.

 

[SP 7M]

Today I had my buddy Kevin come over and we started doing some troubleshooting with a volt meter. To keep it short and to the point, we found out that there were some open ignition coil wires touching each other and the FPR. Kevin thinks that since they were touching the FPR, they grounded and the ugliness ensued.

We fixed the wires and I saw that there was some melted plastic under the ignition coil on its mount. So instead of trying to fire the car up like that, I'm just going to replace that ignition coil. Only the one farthest to the left was looked bad, which I believe goes to the #1 and #2 cylinders.

So now my search begins for a good used one.