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Pierson8706
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01 Honda Prelude SH TDC Noise Fault

 

 

Hello, I have just installed an AEM FIC-6 30-1911 , wired according to the wiring diagram sticky in this forum. The vehicle will start up and idle fine, but I cannot rev over 2500rpm, it immediately stutters and sets a P1391 TDC sensor noise fault. If I install the bypass harness the vehicle runs normally with no fault. I'm currently working on conditioning the input signals for the TDC (top dead center) and CYP (cylinder position) sensors, the crank signal appears solid with no flucuation. Using an oscilloscope, I've managed to lock in the CYP input signal with a 100 ohm resistor. The TDC sensor is giving me some trouble. With no resistor, the FIC is locking onto a minor dip in the voltage just before the negative sine starts, and as such the signal is not synced. I can lock the signal in at idle by using a 780ohm resistor, but the signal loses sync above 2000 and the ignition breaks up. If i go any lower on the resistance, I lose the ability to idle stably. I have saved waveform images of this, but don't know how to upload them. Can anyone give me some insight as to how to lock down this signal?

Pierson8706
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Ok, based on some more

Ok, based on some more testing. The factory signal is too noisy for the sensitivity of the FIC input. I’m going to try using a VR conditioner to output a square wave and use the Hall effect inputs to the FIC. If I do so, will the FIC still output to the mag sensor outputs, or does it only output based on which input is used (mag to mag, hall to hall)?

Pierson8706
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Joined: 04/26/2019 - 08:48
 

 

I have narrowed my problem down to the crank signal. I removed all ignition inputs and re-installed them one at a time. I can have CAM 1 and CAM 2 hooked to CYP and TDC respectively, with the positives intercepted and the negative tapped, without issue. The crank signal will set a TDC noise fault when intercepted on its own (without the CAM 1 and 2 hooked up) so I know for sure it's the signal causing my issue. One thing i noticed using a scope on the crank signal though, the AEM signal is inverted wether I have the crank signal hooked up properly, or reversed. I'm not entirely sure what's going on there. I can also manipulate the igntion breakup by changing resistor values across the + and - input. If i put a 150 on I can rev to 3800 before it breaks up, but the waveform still looks ok.

What am I missing here, or doing wrong?

Pierson8706
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I forgot to add, if I tap the

I forgot to add, if I tap the crank input, but leave the output disconnected, I can read RPM in the FIC software, and it matches the vehicle. It seems to be interpreting the signal just fine, I just can't figure out how to get the output functioning properly.

Guy integra
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Joined: 05/18/2019 - 08:30
Hi i have the aem fic 6 30

Hi i have the aem fic 6 30-1911, i wired it up the same as the obd1 integra diagram and it is throwing ckp error code ob2 reference po336 when i rev it past 2000rpm,. Would a resistor work ive read that a 2.2k ohm 0.5w resistor might work any help would be appreciated.
Its a 1996 automatic honda integra b18b2 (same as acura integra) weird thing is its obd1 ecu plug and has obd2 distributor and it says its an obd2 code.

Pierson8706
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I don't have an answer for

I don't have an answer for you as of yet. I'm still troubleshooting my install. What I have found is that only the crank sensor is causing the problem. I have gotten the car to run by intercepting the CYP and TDC inputs, and tapping the ground inputs for those sensors, leaving the MAG O- disconnected from the FIC. I can only tap the crank input right now to pull an RPM signal, if I intercept i can't rev past 2500 and set a TDC noise fault.

I've noticed that my TDC sync is off, the FIC is triggering just before the rising edge, such that I assume that's why the fault sets. Watching the input waveform on a scope, there is a slight negative "bump" before the actual falling edge (below zero) of the trigger, the FIC is triggering off of that. The problem I'm having is that I can't get that signal to sync properly, no matter what resistor value I try. I can eliminate the "bump" but even then the FIC is still triggering a rising edge output just before the input edge. I've tried flipping the inputs as well (+ to - and - to +) to flip the trigger, but that immediately sets a fault. I'm trying to find a way to sync that signal and I'll post my results if I can manage to do so, it'd be nice if we had a sync setting somewhere like I've heard the EMS does.