Anyone with a Factory Service Manual around know where I can tap into the RPM signal off of the ECU. Just need the pin number going to one of the coils. Preferably the #1 cylinder.

 

You may be able to pull it form the Unified meter and A/C amp box under climate controls. That white box sends the engine speed signal to the tach.

What are you using it for? I am not for sure if there is a single wire for each coil as it uses a network type comunication with the ECM.

 

I just checked, you may not be able to pull RPM from there either.

 

I need it to run to my Wideband O2 setup, so I can log and graph, AFR's, RPM, boost and fuel pressure and then tune accordingly. I can use either a 12volt coil signal or a 0-5 volt signal.

 

Cool! I am having trouble finding it. I can email you a zipped portion of the manual if you want. Just pm me an email that can accept 5mb files.

 

Each coil pack has a colored-striped wire going to it (along with two other wires). This color stripe is different for every coil. Compare any two coils and tap the wire that is different. This is a 4V pulse wave sent from the ECU to the Coil to fire the plug. I have my MSD window switch hooked up this way. I can post pics if needed.

Dan

 

Pin 62 on ecm (Yellow/Red) wire goes to #1 Coil pack You wanna pic or the whole Engine control section of the manual.

First pin third row if looking at the pin outs where there is a group of 5 larger pins immediatly to the left. A pic would help. . . .

 

a pic would be awesome.

 

McDan, thanks for your help, but I don't want to have to run yet another wire through my firewall if possible. Plus, since it's such a low voltage signal, I'd be afraid of loading the ECM down with the extra wire length needed.

 

Here!

 

Next!

 

You have mail too ;-)

 

Thanks for your help guys.

 

Well, I tapped successfully into the RPM signal so I could log RPM and AFR's. However, there was a problem. After looking at the ECU connector I noticed that that pin 62 didn't even have a wire connected to it.

So, what I did was took a D cell battery, soldered sewing needle to the positive end and stuck it into the correct yellow red contact that plugs into the #1 coil pack then I grounded the negative side.

Then I went and took my trusty multimeter and tested for voltages. It turns out that pin 43 is actually where #1 coil is activated not 62. I don't know if this is an error particular to the version of ECU that I have, but for those that want to tap into it the RPM signal, you should doublecheck the manual and not take what it says as gospel, because it was definitely wrong in my particular application.

Oh and if anyone does this ensure that the battery is disconnected first, I almost forgot, which wouldn't have been good.