Need a signal that the engine is started
Discussion
FYI
i got this information from Chimaera FB page:
The alternator put out an earth when not spinning on terminal d+ the alternator light wire, however when the alternator is spinning and thus charging, this same terminal becomes a + feed from the alternator extinguishing the battery warning light on the dash.
i got this information from Chimaera FB page:
The alternator put out an earth when not spinning on terminal d+ the alternator light wire, however when the alternator is spinning and thus charging, this same terminal becomes a + feed from the alternator extinguishing the battery warning light on the dash.
ruggedscotty said:
what you using the signal to do ? if taking it from the alternator and the alternator belt slips and engine is still running could that cause issues ?
So just the same as if your belt driven pump belt slips then ;-) I'd go alternator, personally. It's a static signal, unlike the tacho.
Why don't you use 14CUX ECU pin out 16 which is the fuel pump circuit?
Look for the blue/purple wire going to the fuel pump relay dangling in the passenger footwell above the battery. You will find two paired relays here, the fuel pump relay is the one fitted to a blue coloured holder.
When you turn the ignition on the ECU will ground the fuel pump for three seconds to prime the fuel rail, after that that the ECU will switch off this circuit.... until:
A. You cycle the ignition off and back on again - at which point it'll only go live again for the three seconds
B. The ECU sees an RPM signal at cranking speed or above - at which point the circuit becomes constantly earthed
Please note 14CUX ECU pin 16 (fuel pump) is a switched to earth circuit.
I guess you could also use input pin 32 which will either be a white/black or a white/blue wire, this signal comes from the coil and is what the ECU uses to determine engine speed. Obviously if the engine isn't turning there will be no input signal at pin 32 from the coil.
Personally I'd just take the live signal you need from the fuel pump relay, yes it will become live for 3 seconds without the engine running when you cycle the ignition key. But it is just 3 seconds so is actually perfect for diagnostic purposes.
After the three seconds the fuel pump circuit becomes a very reliable ECU managed engine running signal.
Look for the blue/purple wire going to the fuel pump relay dangling in the passenger footwell above the battery. You will find two paired relays here, the fuel pump relay is the one fitted to a blue coloured holder.
When you turn the ignition on the ECU will ground the fuel pump for three seconds to prime the fuel rail, after that that the ECU will switch off this circuit.... until:
A. You cycle the ignition off and back on again - at which point it'll only go live again for the three seconds
B. The ECU sees an RPM signal at cranking speed or above - at which point the circuit becomes constantly earthed
Please note 14CUX ECU pin 16 (fuel pump) is a switched to earth circuit.
I guess you could also use input pin 32 which will either be a white/black or a white/blue wire, this signal comes from the coil and is what the ECU uses to determine engine speed. Obviously if the engine isn't turning there will be no input signal at pin 32 from the coil.
Personally I'd just take the live signal you need from the fuel pump relay, yes it will become live for 3 seconds without the engine running when you cycle the ignition key. But it is just 3 seconds so is actually perfect for diagnostic purposes.
After the three seconds the fuel pump circuit becomes a very reliable ECU managed engine running signal.
Sorry to hijack this, I am need of something similar but for different reasons!!
I have just fitted a very Chavvy Flame kit (we attend a lot of charity events and shows for kids, I have the noise and just wanted to increase the wow factor and it will never to be used in a Mcdonalds car Park!!)
The kit cuts the coil neg and in doing so I loose the feed to the ecu pin 39 (engine speed signal). My question is, will the feed from one of the aux coils I have fitted be enough to fool the ecu, the aux coils are fired using a relay or does the signal need to be half engine speed?
I was thinking about linking the aux return to the white and black wire before the 6.8k ohm resister and fit a diode to stop it re-feeding the engine coil. I wanted to ask before trying it as I did not want to damage the ecu.
Many thanks and sorry again for the Hijack
Jamie
I have just fitted a very Chavvy Flame kit (we attend a lot of charity events and shows for kids, I have the noise and just wanted to increase the wow factor and it will never to be used in a Mcdonalds car Park!!)
The kit cuts the coil neg and in doing so I loose the feed to the ecu pin 39 (engine speed signal). My question is, will the feed from one of the aux coils I have fitted be enough to fool the ecu, the aux coils are fired using a relay or does the signal need to be half engine speed?
I was thinking about linking the aux return to the white and black wire before the 6.8k ohm resister and fit a diode to stop it re-feeding the engine coil. I wanted to ask before trying it as I did not want to damage the ecu.
Many thanks and sorry again for the Hijack
Jamie
You need the correct spark trigger patten to reach the ECU as its interlocked with the injector cycles so I would not mess with this area in fear of adding extra spikes- you would be better off providing a separate trigger source. As its easiest you could simply use a two way 12 volt relay wired to act as a buzzer- ie- you supply the relay coil through its own closed contacts, that when the coil has power it opens the contacts and removes the coil power and the contacts close again and the cycle repeats.
Many thanks Mark, I have used the return from one of the aux coils (that is fired using a relay as you suggested) and have 'plumbed' it in before the 6800ohm resistor and have fitted a large diode to prevent it back feeding to the ign coil, so the ECU should be getting no more of a spike than it would with the original coil, the ECU is now receiving a 'running' signal and the kit is working very well. I read a previous post that you had written regarding the relay after posting and it makes a lot of sense. Many thanks again 
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