CLRH2O

No seriously... since Sewell Toyota no longer sells this:

Knock Sensor Harness:
822119-50010 (Toyota Part Number)

(and you can find the "Discontinued" part here):
---
http://lexus.sewellparts.com/accesso...1992/4929.html

I've got Code 52 (Left Bank) and Code 55 (Right Bank) on my 1993 SC400 and with the bogging (limp mode / no over 2000rpm action), and bucking at cruising speed/throttle - I'm thinking it's pretty obvious my 21 year old sensors and wiring "sub"-harness need a replacement.


But - this wiring loom/harness/thing is apparently the hardest single part in the universe to find for sale now!

Anyone have a suggestion? It's Thursday July 3rd 2014 - and I need one stat

CLRH2O

Also, why would a 98 - 00 harness *not* work? I found one of those and the seller assures me if I buy it it wont work on my 1993... did Toyota change the knock sensors on the later engines? Aaarg, it sure does looks the same to me :O

t2d2

iTrader: (8)

I don't know the answer, but I would start by looking up the knock sensors themselves and see if the part numbers changed, and more importantly, if the connectors look different.

I fought with knock sensor trips for awhile, but -- knock on wood -- they seem to have subsided with other fixes. Mine was only #55, though, so yours sounds much more likely to be the wiring.

CLRH2O

Agreed - I HAVE to find this cable... and at some point everyone else will too.

At one point I'd just though, screw it, I'll wire my own up - but after (searching extensively) the general consensus here (and on Lextreme) seems to be a resounding "don't do it" due to incorrect impedance and other electrical gremlinz interfering with the signal these guy put out - and more importantly - what the ECU reads in and interprets it to be. Apparently this is a very dodgy area to go off trying to roll your own with.

There has got to be a source out there somewhere still - CL - lets brain power this one and locate it!

I'll let you know if I can find anything, believe that.

t2d2

iTrader: (8)

Good luck! I hope to not need to tap into your research, but I'll be following along with interest just in case. I saved the thread, as well, on the off chance I run across anything.

Southdwn77

Do you have the p/n for the 98 SC400? Thats what I have and I cannot get a call back from THE dealership here. I say THE because I'm on Oahu and there isnt much to choose from! Each time I call the dealer, i get.."shoot I cant find it, let me call you back"

Southdwn77

just got a call back oddly enough.... I was told there isn't a "harness" for the 98?? he said they sell the plastic connector (sensor end) and the 2-wire pigtail separately. Each are less than $10, so I went for it.

Doubt this info helps you CLRH2O, but thought I'd throw it out there

Vrank

iTrader: (4)

Pulling yours out for inspection is the way I'd go about it if it were me and I suspected that as the issue. I there doesn't seem to be an issue that's blatantly obvious and it's not soaked in oil, I'd look at the ecu being the culprit. Making your own would surely be simple. Just replicate what Toyota did. You know how many people that have hacked together swap wiring and the car works fine? Lots. Lots. If I can splice in ten feet of shielded wire to a knock/o2/trigger sensors and run an IS ecu in parallel with a jzx100 ecu and have it function perfectly, I have no doubt a foot or two in your scenario will be fine

CLRH2O

I'm definitely picking up what you're putting down VRANK

If it turns out that I'm simply unable to source the parts, that'll end up being the scenario.

And SouthDwn77 - are these parts you're talking about for the tips (that connect to the sensors themselves)

http://www.toyotapart.com/90980-11166.html

And / or this?
http://www.lexuspartsnow.com/parts/l...219-50010.html


I'm also wondering if this might be of use - if for nothing other than an already loomed wire set that could be snipped and re-purposed with the appropriate tips:

CLRH2O

I thought I'd come back and update this a little bit. Or, well, actually put up some extra into about possible Knock Sensors as replacements and see if anyone has input.

I've found three for this car that appear to be OEM - which one is the right one?

All the part numbers are the same - regardless of if it's on a Lexus parts site - or a Toyota parts site... which as any one familiar with Lexus Toyota parts will tell you, is actually quite uncommon (even though it shouldn't be as they are all the same parts!)

The Knock Sensor for the 1990 to 1997 year SC400 (and whole slew of other cars) is 89615:

http://www.toyotapartsoverstock.com/...ssembly=512629

Scroll down and you'll find three at the bottom on this page all with the same part number but different prices - the first being "California" spec, the second at the same price being what I'm guessing is "regular", and the last being a triple spelling variation of the Matsu****a *type* sensor - for around 15 bucks less.

So - which one is it that I'm supposed to buy? - Having to buy two saves $30 bucks if the cheapest one is the one.

Then there are also these:
http://www.lexussouthatlantaparts.co...961550010.html

t2d2

iTrader: (8)

I forgot about this thread. Mine ended up being the ECU, not the knock sensors or wiring. The lower capacitor that's hidden by the metal bracing had leaked and corroded the knock sensor input terminals. They were was barely any material left to make a connection, so it was tripping sporadically.

I recommend to everyone now to start with ECU capacitor repair. You're going to need it soon, anyway, if you don't already, since they're all beyond their shelf life at this point. You might just get lucky and save a bunch of money on other repairs.

CLRH2O

I generally agree - but I had the ECU rebuilt about 11 months ago. Trying to remember the guy's name - but he's on the boards here I think.

As for sporadically - in my case it's every single time the car is started and makes it more than a bout 2 minutes of driving. Without fail, it will throw the cel and retard the timing 100% of the time tried.

Turning the car off and back on again resets the cel (and timing) and then it throws again within seconds.


So - which one to buy ya think?

Ali SC3

iTrader: (10)

inspect ecu if not ecu then get in there and see how the sensor wires are. the fact that both went at the same time is a little weird. I wouldn't rule out the ecu without an inspection even if it was re-built.
for the wiring I would just re-wire it like Vrank said if they don't have the sub harness. takes extra time but if thats the problem then that is the fix. don't let the shielding touch the inside wire and connect the new wire to the old wire (coming from ecu after wherever you cut it) to the old wire, and the new wires shielding to the old wires shielding. do not ground the shielding on the block its already grounded at the ecu you will create issues.

t2d2

iTrader: (8)

Well, that's good you already have the ECU addressed, but not so good that the simpler and cheaper fix doesn't cover your scenario...

Matsu****a is a good brand in consumer electronics (mostly synonymous with Panasonic), but I have no idea what role they play in car parts and how their quality compares to Denso.

I looked it up on Sewell and 89615 corresponds to '92-94 for section (?) #8401840268 and '98-00 for #8401840269; not sure where '95-97 is covered. Maybe that's part of the confusion with which to pick? The OEM sensor is $158 with your CL discount:

http://lexus.sewellparts.com/oem-cat...C400-1993.html

I know you can buy them for half that on eBay, but I can't vouch for the quality and it's not a job you would want to do twice. It would also be worth checking RockAuto's prices.

edit: Funny that Matsu****a gets censored. Does that speak to their quality?

Vrank

iTrader: (4)

Are you sure this is correct? I'm not 100% on uz, but on jz stuff all the shield grounds come together and then go to earth via intake grounds, no specific shield ground pin for dedicated ground provided by the ecu. I've always just kept the shielded ground cables tied together in a low resistance manner and ran them to ground with no issues, basically what Toyota does only without the bulky continuity plug.