obd0 b16 hatch...knock sensor problems!!!
 

its 91 EF hatch with a obd0 b16.

Code 23: knock sensor.. keeps coming on...

-the knock sensor was broken in half so we replaced it with a known working one.

-exhaust cam was 1 tooth out of time

-ignition timing was wayyy retarded (seriously)

-injector clip on #1 cyl was broken, and hanging by a thread



all these problems have been fixed. We've traced the knock sensor back to the ECU, and checked connections and everything. After the races at langely on wednesday, i drove the hatch home, and CEL on the ecu was flashing 23, 23, 23, 23, 23, 23, 23, 23....>FUCK


im tired of seeing that motherfucker blink?

why does it keep blinking.


The ONLY thing i can think of is this....we currently have a obd1 knock sensor plug on the obd0 knock sensor at the moment, because we lost our obd0 plug in the driveway somewhere?

but i cannot find a diagram of the obd0 plug on alldata, because its%@
Ú<§
r...im thinking maybe the obd0 b17 GSR should be the same thing? harness wise...

The obd1 plug has 2 wires coming out of it, and 1 is being used for the obd0 sensor at the moment. The knock sensor only has 1 pin coming off of it (b/c its obd0) we used the top colored wire coming off of the obd1 plug. maybe we got them mixed up, but i dont think so.

its not really hurting the car at the moment, vtec still bangs hard, and its running fine. but im jsut tired of seeing that light on.


any help would be greatly appreciated!!!!!!!!

Re: obd0 b16 hatch...knock sensor problems!!!
 

What ECU are you using, OBD1? I'm assuming that's where the ODB1 harness came from?

It's possible that the broken knock sensor damaged the knock input circuit on the ECU, I doubt it but it's a possibility.

I'd double check the timing too, it could actually be knocking..

Find a PDF manual for an OBD1 car with a knock sensor or a OBD1 harness pinout and verify that you have the right wire on that connector too. You have a one in two chance of getting the right wire without knowing which one it is supposed to be.

On most of the OBD1 cars, the knock sensor signal going to the ECU is a red/blue wire, I think the DX may be white though, it's an oddball.

Here, have fun with some tech info.
http://www.ff-squad.com/technet/index.htm

Re: obd0 b16 hatch...knock sensor problems!!!
 

no its a pwo jdm b16 ecu. which is obd0.

the timing is fine. everything is in time just like it supposed to be. the ignition timing is set to stock specs also.

the timing was off last week, but i re-timed it and its good now. i checked and double checked.

Re: obd0 b16 hatch...knock sensor problems!!!
 

the only thing that is obd1 is the knock sensor plug that we got off a buddys car that was running chrome with the knock sensor delete function.


everything is obd0, motor/ecu/harness/knock sensor.

i need a wiring diagram for a obd1 knock sensor plug, and obd0 knock sensor plug?

anyone?

Re: obd0 b16 hatch...knock sensor problems!!!
 

For OBD1 knock sensors, it's the top of the two cavities, closest to the latch that you depress to release the connector from the knock sensor. I'm looking for the OBD0 connector to verify. It looks like the OBDo knock sensor uses the same 2 pin connector, so as long as you're in the right cavity, you should be fine.

Can anyone verify that the OBD0 knock sensors use a 2 pin plug (I know they would only use one wire, with the other cavity empty)..

Re: obd0 b16 hatch...knock sensor problems!!!
 

yes they use the 2 pin plug

Re: obd0 b16 hatch...knock sensor problems!!!
 

just for giggles did you happen to unplug the ecm to clear the codes? if your unsure of the wiring and you have a spare 2 pin plug just tie the two wires together and feed it to the KS pin on the ecu. i have old OBD0 pr3/pwo diagrams if you need it. if that does not work you need to make sure your feed wire is shielded as the KS outputs a FREQ HZ signal, and its very sensitive to electrical interference. but then again maybe the engine is really pre-igniting?? :dunno:

Re: obd0 b16 hatch...knock sensor problems!!!
 

ok so tie both knock sensor wires on the plug into one wire, and run it to the ECU.


this car was converted to obd1, but when the previous owner sold the car to me, it was converted back to obd0.


everything is fine, and in the correct spot like it was never converted. im just having problems with the knock sensor throwing a code.!


any more ideas?

Re: obd0 b16 hatch...knock sensor problems!!!
 

try reseting the ecu? Is the check engine light actually on. The ecu stores the code for a cel it throws until you reset the ecu.

Re: obd0 b16 hatch...knock sensor problems!!!
 

I reset the ecu and disconnected the negative bat terminal and anything and everything else I could think of



The cel is not on at the moment but the light on the ecu is still flashing 23

Fuck me!

Re: obd0 b16 hatch...knock sensor problems!!!
 

oh its one of those. that is a EMI issue. not a hard code but a pre code. the ecm is seeing a spec just outside of that sensor, whether its noise feeding back to the ecu or a dirty or bad sensor reference ground. common on alot of pr3/pw0 ecus. those ecu's are very sensitive to noise, but ive had that happen to me once and turns out the ecu was bad :(

Re: obd0 b16 hatch...knock sensor problems!!!
 

well maybe...


im running open header at the moment, no interior, no carpet, and its been wire tucked. so everything is sitting on the passenger side floorboard, tiewrapped to my cage.


any suggestions?

Re: obd0 b16 hatch...knock sensor problems!!!
 

You might have a problem from the wire tucking. Once you start moving the location of wires, and bundling things together that weren't bundled together before, you may find you have unexpected noise issues. I'm not really a fan of wire tucking, I was an electronics technician for too many years to accept the problems/compromises with noise and service access that are created when doing wire tucks. If the wiring is stock and works great, don't cut it, extend it, move it, change it, whatever. Any modification is usually asking for reliability and performance problems, and that's a risk that you choose to accept.

You only need the one wire coming from the plug going to the ECU, and it should really be a shielded cable like the stock knock sensors use. You've verified the pinout of the knock sensor at the ECU, and done all of that stuff, so that you can try another ECU without damaging it, correct?

Re: obd0 b16 hatch...knock sensor problems!!!
 

i can try another pr3/pw0 ecu, but i dont know anyone with a JDM obd0 b16.


and the wire is shielded. its running directly from the KS, to the ECU. i believe its a 14-16ga. wire.

i mean its crimped/heatshrunk and everything.

but the ECU is sitting on the floor, on top of the fusebox from under the hood.

like i said i didnt do the wire tuck, but this is the only problem im having at all.


its retarded. ill try another ECU.

Re: obd0 b16 hatch...knock sensor problems!!!
 

:eek: :wow:sorry never a big fan of crimping... soldering is the only way for excellent connections. btw the shielding on the wire only works if its grounded

Re: obd0 b16 hatch...knock sensor problems!!!
 

ok, well then , its insulated


and i bet if i solder it, the CEL will still be there.

Re: obd0 b16 hatch...knock sensor problems!!!
 

try another ecu ... i did this fucking song and dance and even assumed the motor must be knocking ... and the fuckin ecu was bad ..but you said the two wires on the knocksensor are running to one? one is the ecu wire and one is the ground i believe.

Re: obd0 b16 hatch...knock sensor problems!!!
 

no on obd0 KS, there is only 1 pin. on the obd0 KS plug there is only 1 wire that runs directly to the ECU.


im using a obd1 KS plug right now. and its running straight to the ECU.

Re: obd0 b16 hatch...knock sensor problems!!!
 

I know you're probably talking about the red/yellow/blue insulated butt splices, and you're right, they're bad. But the fact is that using a proper uninsulated crimp splice, which starts as a "U" or "V" and crimps into a "B" shape, is far superior to soldering. Soldering is easy and cheap, and you don't need any special parts, so that's fine, but it's not superior to crimping by any means. Solder joints wick flux up into the wire strands, and cause horrible corrosion problems (solder flux is pretty corrosive), and the soldered portion does a really poor job of transferring vibrational fatigue across the joint. Basically, soldered splice joints corrode and break. The crimp splice I'm talking about is the type that Honda uses to splice a few wires right at the ECU, such as the shield for the knock sensor wire, and are usually brass. I use them for all of our race harnesses, and I've never had one fail at the joint, unlike the solder joints on the rigged-up dyno harnesses. These crimp splices are very widespread across the automotive industry, which is why I know about them and the reasons they are used.

If you've never had a soldered wire splice fail, good for you. It's only a matter of time, and the car may never see enough use for the solder joints to fail. But don't say crimping isn't the way to go, because the entire automotive and motorsport industry would disagree with you. Underhood harnessing is not the place to solder.

Re: obd0 b16 hatch...knock sensor problems!!!
 

i can agree and disagree. ive never had a solder joint fail but most guys use the standard "butt splices" for splicing so i was referring to that as a poor way of splicing. i can agree about the corrosion issue but then again how long would it take for the corrosion to eat up the wires? years? and copper corrodes too :o i can agree that crimping the ecu pins is the way to go (i do that when i can). But i am a mfg rep for Tyco/Amp and Molex and crimping pins is reliable but that isn't why mfg's go that route, they do that for cost savings. its faster and easier. so before i get off topic about this... we are talking about splicing/crimping in two different categories. im talking about harness joints and lap joints and you are talking about pin termination, either way, its always better that wire nuts or butt splices :beer:



but to get back to dorko, try another ecu

Re: obd0 b16 hatch...knock sensor problems!!!
 

damn man...sounds frustrating....try kicking it :dunno: ;)

Re: obd0 b16 hatch...knock sensor problems!!!
 

I'm not talking about pin termination, I'm talking about splices. They're actually AMP/Tyco open barrel crimp splices, you probably rep them and don't know it... You'll find a lot of spliced wires on most cars/motorcycles from the factory, and they all use this type of crimp splice. You will be hard pressed to find a single solder joint on an automotive harness because of the mechanical reliability problems, especially the stress concentration at the end of the solder joint where the solder has wicked up the wire strands.. I work for an ECU manufacturer, and all of our customer's harnessing uses crimp splices, as well as our sister company's harnessing. There are various SAE whitepapers on this subject too, but they're boring and long winded. Yes, you can save time by crimping over soldering, but that's not why they're spliced. I know this is going way off topic, and I'm sorry. I'm not giving any ground on this though.

By the way, what rep do you work for? I'm not asking because I don't believe you, I'm asking because I'm curious and have dealt with a lot of connector reps and distributors over the last decade and change of working. I'm always looking for new ways to get the cool and hard to find AMP/Tyco waterproof connectors that don't exist on the public market, for my motorsport projects. I wish I could get them through work, but they go direct to our manufacturing sources.

Re: obd0 b16 hatch...knock sensor problems!!!
 

ok guys lets get back on topic here.

i appreciate your help, but your conflicts of interest about soldering, and crimping are not helping?


any tips?

try a shielded wire?

Re: obd0 b16 hatch...knock sensor problems!!!
 

I thought you were already using a shielded wire? Yes, that's quite important, you should be using a shielded wire if you aren't already. The shield should be terminated to the power ground of the ECU (I think). Or is it the transducer (sensor) ground. I don't remember. Anyway, maybe someone can clarify that for you, but I will say for sure that the shield should only be terminated on the ECU end only, so there are no differences in potential from one end of the shield to the other. That means no ground loops.

Re: obd0 b16 hatch...knock sensor problems!!!
 

no its insulated, not shielded.

i mean its a fucking 14ga. wire that i got in a roll from autozone?

i mean i think the rest of the harness is the same type of wire, why not use it for the knock sensor?


am i missing something?

Re: obd0 b16 hatch...knock sensor problems!!!
 

The knock sensor is a transducer, sort of like a microphone. It puts out a voltage based on what it "hears", and this is a fairly low voltage signal and quite prone to interference from induced noise. This is why the shielding is important. Do you still get a knock sensor CEL when the engine is off and the ECU has been reset?

Re: obd0 b16 hatch...knock sensor problems!!!
 

yes.

it wont set the CEL, but it flashes in the ECU.

i can turn the car off, reset the ECU, and the light will stay off (in the ECU) for about 5-10 min or so. After driving the light in the ecu will start to flash. But the CEL wont illuminate.

i mean i can ignore it if its not a big deal, but if im sacrificing power for a fucking KS then im going to try and fix it.