I need help !!!!

Currently trying to figure out install of a controller for my direct port kit. I need to tap into the RPM signal and a 0-5v power input signal from the ECU. Can anyone send me a wiring diagram so I know where to tap into. I know where the ECU is and can access the harness pretty easily.

 

aahhh.....nevermind...i figured it out...modern cars wont have a tach. signal wire. I have to tap into the crank position sensor and the camshaft position sensor, which share a common hot wire. then route that to my controller to determine RPM...I can then tap the crankshaft sensor to my controller which will provide information that allows for controlling timing retard to match the amount of power adder being used...woohooo!!!

sometimes I amaze myself..I LOOOOve having manic episodes..I get so much done !!!!

 

That's going to be tricky, there isn't an RPM signal as such - the closest you'll get is the crank position sensor, which the wiring diagrams show as connecting to pin 6 (signal) and pin 30 (gnd) of connector C1E117:


The problem is, you have no way of knowing if this signal is the right level (hall effect sensors are incredibly subtle) or whether you'll upset the ECU by tapping into this wire (and you likely will).

To be honest, since the ECU translates the RPM information from the crank (and maybe cam) position sensors onto the CANBUS I'd be looking at tapping into this to get the signal you need - Emissions regulations require engine speed in RPM to be sent as an unprotected message so all OBDII readers have access to it. A bit of searching revealed this on ebay which would be how I would tackle this

 

I emailed the seller. I am not understanding how this module works exactly. From what I understand, I would wire it directly to the corresponding color wires that goes into my OBDII port. If that is the case, then I could just tap into the yellow wire going into my OBDII port to get the tach signal???? The module confuses me .... ;P


Do you think I can I fry the ECM if I try piggybacking into the 5V line of the crank position sensor?

Also, Here is the suggested wiring for my application, since we dont have an ignition coil, I assume they want just the CPS signal going into the R12 terminal of the controller to get RPM:

 

So that module actually taps into the CANBUS wires (high and low) and decodes the CANBUS data to provide an RPM signal you can use on one of the other wires. It should be pretty simple to find out which wires in the OBDII port are your canbus high and low wires, and then just give the module power from other pins.

A lot of the wiring diagrams like the one you posted that talk about using coils etc are pretty out of date and as you've already stated engines generally don't work that simply any more

 

Out of date indeed... 30 years?

The workshop manual (free download) has the wiring diagrams...

 

@davetibbs...again, thanks for the help. I am following your 5.0L build thread and learning alot from it. I appreciate the link to the CAN BUS interface.

I also need to find a ECU and PWM ECU signals. I am going to contact the builder of the interface to see if he can customize his box to convert those signals from the CAN BUS.

EDIT**** found the PWM signal going into the OBDII port but the CAN BUS interface does not have a corresponding wire. I wonder if the controller will be able to use the PWM signal directly from the car ECU?

 

You're not understanding the car (this car or indeed just about any car in the last 30 or so years).

PWM is used for signalling. The signalling is used for packets of data. A particular packet may request and another provide the data you talk about. There will be vast numbers of other packets.

Similar for CAN.

There's no "wire" with what you mention, except if the actual sensor itself has a wire. Beyond that it's all data packets.

 

Yes, you are right, as I mentioned, I haven't put any time into understanding the way data communication works in today's vehicles, what I don't know is if the controller will be able to decipher the data and convert it from stepped digital to smooth analog. There has to be a way for the controller to get a signal from the ECU whether it is through the interface or directly from the PWM signal right? Otherwise, the only signal the controller will be able to receive is a RPM signal, which kinda defeats the purpose of purchasing a $700 controller that has lots of functionality built into it. This probably will be resolved once I hear back from the manufacturer.

 

Via OBD any of the sensors can be read. Even a $5 (£5) elm327 can do it.