I own a 2001 ap1 S2000.
It's complete stock with a cold air intake.
I have this problem since I bought this car.
When the cel comes on, I can't rev past 3K rpm.
Checked at the dealer what the problem is and they diagnosed that there is no signal from the top dead center sensor #1 (tdc)
It's the sensor that's mounted at the valve cover at the intake side.
I bought a new sensor and I still have the same problem.
Checked the wires where I could reach and everything seems OK.
When I reset the ecu, the cel dissappears, but after a few hours driving, sometomes 1 day, the cel comes on again and can't rev pass 3k rpm.
I switch the car off and start it again, the car revs till 9k, but the cel is still on. It happens more if the air conditioning is on.
Could somebody out there know what is wrong?
Any help please!!

 

I personally would pick up the honda shop manual for the S2000 and just follow their troubleshooting steps. I don't have mine in front of me but if you've already swapped the part with a new one and are still showing the same code then I would check the wiring. you'd have to make sure the sensor is getting power, has a good ground, and that there's continuity from the output wire of the sensor to the ECU.

 

You mean that I have to check the two wire from the sensor to the ecu.
That's a hell of a job, because most of the wires are below the intake manifold and after that thru the firewall and then below the dashboard to the ecu.
I noticed a small movement of the plug connected to the sensor. Could that may be a problem??

 

it could the the plug making an intermittent connection. when I say check continuity I mean use a multimeter and connect a wire from the TDC sensor plug and then check the right port of the ECU harness and see if you're getting a complete connection through the engine harness. so basically you're making a big loop with the multimeter in the middle. a good connection would read 0 ohms (or very close depending on the gauge and resistance of the wire). 0.5 ohms wouldn't be good, anything 1 ohm or higher would definitely be a problem.

if you don't get a good reading then the wire itself or that connector is your problem. if you get a good connection it's either the sensor itself or the ECU. if you've got a buddy with an AP1 you could swap ECU's to test that. to get around the immobilizer you'll just need a blank copy of your key (without the immobilizer chip) and tape his key to the new key. the car will match his key's chip and ECU and let you start the car with the new key, according to the manual anyway.

 

Can the ecu just be bad that it gives that cel code everytime?
What could be a reason for that?
If I buy a used ecu, would it start with my own key.
What should I do then?

 

a bad ecu is possible, your best bet is to test it out before to go through the hassle of buying another one in case that's not the problem.

 

Hey guys...
I'm trying to follow along this thread as best as I can.. not much of a mechanic at all... BUT from what i can tell, Im having the same exact problem with my s2000 (2000 model)... I've actually been having this problem for about two years and the Honda Service Center is just clueless here (i live in the UAE). I've all but lost hope.. check it out, maybe you guys can help:


like i said, its a looong story, let me just explain where im at now.

So, my CEL is on, permanently. I've tried to get it fixed a bunch of times. They replaced a couple sensors one time.. and all the other times they say there's nothing wrong.. they just reboot or restart the computer.. and each time.. a couple days later, or a week later, or whatever it is, ill be driving, and the engine cuts off on me and the LED lights permanently again.

when i say 'cuts off', what i mean is ill be driving, and all of sudden i feel as if I very suddenly cut off all gass, and i jerk forward... my immediate reaction is to let go of gas, and i do.. after that, i can rev past 3000.

A few months ago.. whenever this happened, my life was hell for the next week or so, during which i would need to stay below 3000. Then it would be a trial and error kind of thing. Try going above 3000... usually after a week or so.. it would work again.

You can imagine how anoooooying this gets after a period of time when its happening like once a month. Im sure your thinking why dont u just fix it. I TRIED... noone knows what's wrong with it. so then i devised a trick.. dont laugh.

as soon as i get in the car, turn it on and while in neutral, rev it past 3000.. if it goes past without cutting of.. im good to go.. engine wont cut off while driving. if it does cuts off at 3000 though.. turn the car off and repeat the process until it does rev past 3000.. usually will work the first time. The benefit of doing this 'test' while in neutral is that if it does cut of, at least i don't have to spend that week driving under 3000 rpm.. which completely SUCKS on the highway btw..

so..
that is the nasty situation im in.. my 80,000 service came up this week, so i sent it in, and as usual i raised the issue of the engine problem. now they are telling me that they want to replace the TDC and the CKP sensors.. did my basic research to see what they are... and that didn't really help in figuring out what the real problem is. im gonna go ahead and change the sensors, but i get the feeling that next week, the whole thing will start over again.

IF you have found a solution to your problem.. PLEASEEEE SHARE>>> and if you guys have any suggestions or ideas, also, please help..

thanks
and sorry for the very very long post.