Help! Damaged throttle wiring potentially

[pilgrim_traveller Junior Member Find all posts View Profile Close pilgrim_traveller]

Hi all

Was installing electric brake controller today and so far that side of things went well. It powers up which made me very happy. However I then went to start the car and I had a weird low idle then an engine light then normal idle. Couldn't think about what it could be so put it in gear, went to accelerate and nothing! Floored it and only when fully floored does it start to accelerate.

While installing, I had the accelerator harness disconnected for several hours while the battery was still on... I'm HOPING maybe it just needs a TPS reset. But my gut is that I damaged something in the rubber seal plug between the cabin and the engine bay. If I stick my finger in there, something feels a little sharp. Potentially I caught the edge of something when putting another hole in there for the brake controller power

Is there anything I can try that doesn't involve pulling the whole dash out to get to the throttle cable? IS there a TPS reset for the Prado? Any advice if I DO have to pull the dash out? Can that big rubber grommet come out somehow? There's not much slack in the wiring that's all taped together in there.

Value any advice... We'll be borrowing a car until I can figure this one out I feel!

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

Oh what a sinking feeling, I don't think disconnecting the connector would cause an issue. You could try disconnecting the battery for 30 minutes or so and trying again, else if you have an endoscope see if you can get it in there and see if you have damaged the form. If you have then you will have no option but to remove and replace or fix.

Cheers Leigh

[Guest Close Guest]

Is it in limp mode?

You may be able to retrieve a fault code that will also tell you what's going on. Anyone you know with a scan gauge or similar ?

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

Which wiring loom rubber did you go through the one on the right or the left ?? [IMG][/IMG] I used the one on the right and then used some silicone to seal up (I doubt it would have leaked anyway) There are two little nibbly bits of rubber where I have ran the wires through for UHF and permanent power for fridge, I just cut the tips off them and ran through there (as per pic below) Why did you have to disconnect the throttle accelerator harness ?? any particular reason ?? Im doing my brake controller tomorrow and another permanent power wire for the other side in the rear cargo area. I've had a look and cant see why I will have to disconnect the throttle harness...Your right there is no flexability in either of those harnesses and would be a lot of connections to come apart to even get to the loom to check it out. I think it may be an auto lecci job for you unless some thing has just earthed out or some thing when you have damaged the wire. Although unless you cut it dead set in half it should still be working (just my thoughts).....Unless as piggy has said you can get a scan gauge or similar to read the code........... [IMG][/IMG] Cheers Steve

[pilgrim_traveller Junior Member Find all posts View Profile Close pilgrim_traveller]

Leigh - definitely was a sinking feeling! Don't have an endoscope but might pick up an SCA one for $50 tomorrow. Tried everything I could today to figure out which wire(s) are damaged and am unsure. I put a multimeter between the accelerator connector and throttle body connector before realising they are actually a different harness (goes through ECU I guess - almost impossible to trace where it goes).

Piggy, not sure how I tell if it's in limp mode? It barely moves unless I'm flooring it and has an engine light lit Neighbour repairs forklifts and the like for a living, he might be able to get a scangauge. Will ask him tomorrow. Any standard list of fault codes for Toyotas?

Steve, went through the driver side one. I was using a drill to get a hole in it. I don't recall seeing any nibbly bits to pinch off but in retrospect that would have been wiser and I'd probably be sitting here relaxing now instead of learning about wiring harnesses I disconnected the throttle harness just to get some space to work - it was very tight under the steering column.

Will hope to get a camera up it tomorrow and HOPING it's not that bad. Scangauge hopefully will show me nothing else gone wrong too. Then to find a good local lecci who won't rip me off.

Presuming the only issue is that I've gone through (shorted or earthed) some wire(s), does anyone think a feasible DIY is to cut the whole harness going through the rubber grommet on both sides and solder new cables between them? This would SUCK to do (guessing 20-30 cables of various gauge sizes) but if it looks like becoming an expensive job to get a lecci to do, would this be feasible? Or just asking for problems? Would be a very average weekend if I decided to go that way Otherwise maybe I can just try and (gently) cut all the tape back on both sides to get some slack on the wires in question to deal with those...

Any way I look at this situation, it just sucks

Thanks all for your thoughts.

[RanJ Avid PP Poster! Find all posts View Profile Close RanJ]

I was using a drill to get a hole in it.

Oh dear. This is not an easy repair mate. It won't need a replacement loom but it will take some careful use of some wire and a soldering iron. As LeighW says.. having the throttle unplugged for a period and then reconnect shouldn't throw any lights or cause any problems.

I'm going to assume you have caught one of the 5V returns from the pedal worse yet, it may not even be the TPS or throttle thats been damaged although it's sounding like it has.

Future reference, Stanley knife to pierce and then feed your cable in through that. Don't need a round hole... just a little slice.

[pilgrim_traveller Junior Member Find all posts View Profile Close pilgrim_traveller]

Thanks RanJ. Yep lesson learnt for next time! Everything else SEEMS to be working fine. Just won't accelerate properly. Hope it's just that the pedal is now running one or two strands of copper or earthing out, rather than anything else.

[Guest Close Guest]

Any connection of a low voltage TPS should carry the signal. Even if just one core of a strand left connected if you really have damaged them.

You may be ( but I doubt it) hunting a ghost and damaged loom when it's really something else.

I'd be checking fault codes etc before anything to see if anything is throwing up.

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

Don't even contemplate cutting the harness, either repair or replace.

I suggest you undo any retaining devices under the dash to give you a little slack in the form if possible. On the engine side carefully remove insulation tape from boot, prise boot out of hole in fire wall and hopefully you will be able to "roll" the boot back over itself to give you access to the wires.

Before doing that though I would suggest as above, get an ODBII reader on it if possible and see what error it is throwing. I personally would disconnect the wiring you put in for the brake unit just to make sure it is out of the equation and carefully check all the connector and wiring where you have been working for damage not plugged in fully etc. Also all fuses, it would go the form only as a last resort as you may not have damaged it, hopefully the camera will prove one way or the other.

Cheers
Leigh

[winniliss Avid PP Poster! Find all posts View Profile Close winniliss]

Disconnect the battery first as well...

[pilgrim_traveller Junior Member Find all posts View Profile Close pilgrim_traveller]

Some great advice here from everyone, I feel much more confident about taking on the diagnosis of it now. Appreciate how quickly everyone has offered their wisdom! I'll spend some time poking around now and see what I can find.

Thanks

[pilgrim_traveller Junior Member Find all posts View Profile Close pilgrim_traveller]

One more quick thing... I'm probably going to buy an OBD scanner as I'm sure I'll be needing one more as I start to do more work on the beast. I have a 2005 GXL (1GR-FE). Does this one use OBD or OBD2? Found a post on this forum indicating Toyota only started supporting OBD II from 06/07. Have found these two scanners, which one is the type I need? Thanks!

http://www.dtdauto.com/Product/Produ...I%20Scan_E.htm

http://item.mobileweb.ebay.com.au/vi...d=261234969855

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

That's a catch 22 situation, if your car does not support ODBII you'll probably find it doesn't support earlier ODB's, I'm fairly sure the Australian models used proprietory until ODBII, I could be wrong though.

Cheers
Leigh

[pilgrim_traveller Junior Member Find all posts View Profile Close pilgrim_traveller]

Got an endoscope yesterday (Jaycar $45 with LEDs, waterproof, etc) and saw definite signs of damage in the rubber seal but too difficult to see WHAT was damaged. Found that the throttle would intermittently work (and engine light intermittently turn off) while wiggling cables around.

This morning, pulled all the tape off the engine-side seal/loom to find that the wires are sikaflex'd into the grommet. Grrrr... The engine bay is SO well sealed off from the cabin, it's ridiculous. Anyway, after pulling off half a dozen clips and the air filter housing etc, managed to get enough slack to push the loom (grommet and all) through about 5cm into the cabin. Once through, I can see one wire that is definitely now two wires, and a couple of others that have been nicked but still seem intact. The one that split in half is one of the wires from the accelerator pedal so that explains the throttle issues. It's the brown-white one here:

http://s1344.photobucket.com/user/pi...03de2.jpg.html

So the next thing to do is to decide if I spend an afternoon swearing and burning myself on a soldering iron in a confined space... Or run a new wire from the accelerator (stanley this time, no drill!). The cabling diagrams I'm looking at are crazy... I'd say the latter will result in the more reliable outcome. Really don't like the idea of my throttle relying on a solder joint in that space. Will have to see what else is damaged as well and decide what to do with those.

[RanJ Avid PP Poster! Find all posts View Profile Close RanJ]

Running it directly to the ECU from the throttle body? Well, it's exactly what I would do but thats me. I would confirm direct continuity first though. Although, judging by the diagram... I would say yes, but you need to find the plug that is IC3 first and confirm that the wires are not spliced elsewhere. It's a big plug and judging by the diagram White/Blue is in Pin20 so it has at least 20 wires in it.