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A51young check to see if you have a signal at the ecu with the engine running. If you have a signal.check your capacitor on the KS circuit. Where are you in AZ? I'm in Tucson
There is signal at the ECU, after I ended up drilling a hole in my lift hook and mounted the old knock sensor and pigtail, intermittent CEL with the old pigtail though, but got a new pigtail and it's great.
I'm pretty positive the shop that rebuilt my engine put in some cheap knock off sensor and charged me what an oem sensor costs.
Looking like I'm going to have to go in there and replace the knock sensor with my old one
I do, but only for MKIII Supras. I've only worked on a few 3vz powered trucks, so I don't know how long a wire to use, or even what connector they use.
As for the 22re, I would have to find out if the connector is available from Toyota or not.
this code 52 is driving mi nuts thinking about the coaxial cable you mention to see if i can run it strait to the ecu some how, thinking to cut the connectors and weld the wire together
and do the same at the ecu end, i put a new ks. it came with the connector but the one coming from the ecu was toasted, i have power at the ecu none at ks. any help wood be appreciated
I check for continuity on the wire coming from the ECU and it checks out OK , however i don't have the 5 V. led coming to the KS.from the ECU with the ignition on.is this means the ECU. is bad? i which there was a definite test for the KS. with out taken a part the hole motor
The illusive Code 52 - I've been reading these threads - and trying to exactly diagnose by problem - 91 Toy 3VZE 3.0 recently rebuilt. Replaced the knock sensor with an after market - and the code 52 did not go away. Engine runs OK til the CEL comes on and then it runs horrible. Real sluggish - doesn't like to accelerate.
Yesterday I replaced the distributor with a new one - and now it runs great with good acceleration! Yea! But the code 52 still pops up! Trying to figure this out....
i just did the ks relocate to avaid going into the engine but i still have the code. upon closer inspection i found some of the insulation cracked and flaking off of the wire coming from the harness could this be the problem im going to strip more of the loom off to see if there are any more damage
Hey folks, I'm back with more stupidness. Still rolling with the code 52, it went away for a while but gradually came back (someone else three pages back had the SAME issue). I'm just gonna bit the bullet and rewire it to the ECU. Now, I'm looking at this 24AWG wire from digikey. Very cheap $6 for 5.0m, but is this too thick? I think thats what the factory wire spec is. Another question, I saw some confusion about ECUs and ports, is there a definite guide to rewiring back to the ECU or is it just assumed knowledge. I'm handy at soldering, and hopefully handy at not breaking my ECU.
I've seen a couple of pinouts on the web, I'm assuming that this is the right one? (1993, 4WD, Manual):
My plan is simple, make another connector (waterproof, sealed) on the end of the pigtail and the end of this cable, run the cable around the front like the current wire and go through the firewall into the cab, cut the current KNK wire and solder mine in, right?
Your digikey link didn't work. 24AWG CORE should be plenty (it's basically an audio signal), but the wire has to be shielded. (Just picking one at random, this should work: http://www.digikey.com/product-detai...5-1-ND/5270196 )
I don't know how the ground is connected at the ECU. My EWD shows it picked up by a Brown wire that ends up on the camshaft bearing cap eventually, but I suspect you will find that Brown wire near the ECU connector (there are several other shielded leads, like the OX1 and OX2 lines, and the lines from the distributor NE, G1, G-, G2). For what it's worth, the shielded is grounded only at one end (not the knock sensor end or the pigtail connector). I suspect that's to stop what audio guys call "ground loops."
Splicing to the existing wire would probably work, but a much better arrangement would be to replace the KNK pin in the connector with one crimped to the new wire. Connector re-pinning is a step up, and this might not be the first job to test your skills. Your choice.
Your digikey link didn't work. 24AWG CORE should be plenty (it's basically an audio signal), but the wire has to be shielded. (Just picking one at random, this should work: http://www.digikey.com/product-detai...5-1-ND/5270196 )
I don't know how the ground is connected at the ECU. My EWD shows it picked up by a Brown wire that ends up on the camshaft bearing cap eventually, but I suspect you will find that Brown wire near the ECU connector (there are several other shielded leads, like the OX1 and OX2 lines, and the lines from the distributor NE, G1, G-, G2). For what it's worth, the shielded is grounded only at one end (not the knock sensor end or the pigtail connector). I suspect that's to stop what audio guys call "ground loops."
Splicing to the existing wire would probably work, but a much better arrangement would be to replace the KNK pin in the connector with one crimped to the new wire. Connector re-pinning is a step up, and this might not be the first job to test your skills. Your choice.
Thanks scope! I ended up ordering the exact same wire but 5m of it instead of 1m. Weird about the link. I'll look outside under the hood tomorrow (brrrrr) but I think you are right according to the diagram I saw it was brown.
I've re pinned a couple of connectors but I'm not the best at it. Its not difficult just frustrating. Might as well do it.
EDIT: when I get around to it, I'll take photos for others to see
One more quick question, I've already modded the pigtail coming out of the block (long story, but its new from dealer) but I can't remember what polarity I used, because I assumed black->shielding, brown->sensor, but its really black->sensor, brown->shielding. If I checked for continuity between the block and the shielding (not plugged into the harness, just to the sensor), it would ground, right? Is there a better way for me to check polarity? Fire it up and check for millivolts?
Looking into the harness-knock sensor connector, in the direction of the knock sensor, the shield side should NOT ground. It should be connected to nothing (it's only connected to ground at the ECU).
Alas, it is really hard to check if something is connected to "nothing." And the resistance of the knock sensor itself should be about infinite (it's like a microphone). So, yes, you should get a small AC signal on the sensor wire when running (so check for millivolts on the AC scale). Unfortunately, since the shield will be connected to nothing, you might be able to also read induced voltage. Try grounding what you think is the shield side when measuring the sensor side.
Looking into the harness-knock sensor connector, in the direction of the knock sensor, the shield side should NOT ground. It should be connected to nothing (it's only connected to ground at the ECU).
Alas, it is really hard to check if something is connected to "nothing." And the resistance of the knock sensor itself should be about infinite (it's like a microphone). So, yes, you should get a small AC signal on the sensor wire when running (so check for millivolts on the AC scale). Unfortunately, since the shield will be connected to nothing, you might be able to also read induced voltage. Try grounding what you think is the shield side when measuring the sensor side.
Yeah, I figured as much, since you're right, it wouldn't be grounded on this side. I might just pull the plenum up and snap some photos to see if I can get at it. I've soldered a new connector on the pigtail without removing the plenum, so it shouldn't be any harder than that (seriously, no idea how the hell I did that)
With all the electrical noise going on in the engine compartment when the engine is running, I'm doubtful you'll be able to tell anything by hanging an ac voltmeter on either pin of the connector. The ECU filters the KS signal heavily to separate the signal from the noise, but the ac meter just measures everything indiscriminately.
You "might" be able to tell which is the signal lead by leaving the engine off, connecting the ac voltmeter between the supposed signal pin and the block, setting the meter to its most sensitive range, and tapping the block with a hammer. Watch for a brief jump in the meter reading. The lead that jumps the most will be your signal lead.
With all the electrical noise going on in the engine compartment when the engine is running, I'm doubtful you'll be able to tell anything by hanging an ac voltmeter on either pin of the connector. The ECU filters the KS signal heavily to separate the signal from the noise, but the ac meter just measures everything indiscriminately.
You "might" be able to tell which is the signal lead by leaving the engine off, connecting the ac voltmeter between the supposed signal pin and the block, setting the meter to its most sensitive range, and tapping the block with a hammer. Watch for a brief jump in the meter reading. The lead that jumps the most will be your signal lead.
An oscilloscope is ideal for looking at the output of the KS, but one fairly effective poor man's substitute would be to use the mic input of your laptop. Build a cable to go from the KS pigtail to your mic input, open up a copy of Audacity, set it to record from the mic input, and then tap on the block. It should be easy to see the AC waveform from the KS if things are connected.
An oscilloscope is ideal for looking at the output of the KS, but one fairly effective poor man's substitute would be to use the mic input of your laptop. Build a cable to go from the KS pigtail to your mic input, open up a copy of Audacity, set it to record from the mic input, and then tap on the block. It should be easy to see the AC waveform from the KS if things are connected.
That is a STELLAR idea. The biggest issue is finding time to tear it apart and re-do it. I'm thinking that I'll just run it on top of the current harness back to the ECU just to get it working (hopefully). Kinda nervous tearing into my ECU connector.
Also, the wiring came in today! Might do this tomorrow after I replace the rotors and pads.
Blech. It went away for a while and came back, but it seems only like it comes back when its cold. After work, it dropped 30 degrees, fired it up, code 52. After movie tonight, it dropped again, code 52 (but only on the second stop and restart at the gas station). I am running the external KS, but only because my internal one just plain doesn't work.
Question, if oil or antifreeze leaks into the valley where the KS is located and accumulates can it short out the KS or the connection between the pigtail and KS?
11-03-2015, 01:25 PM
