Hey guys!
I searched first.
So I just put a S4 engine in a FB.
Looking at the wiring diagram. It looks like all I need to hook up the ECU is:

Black/yellow wire to 12+(coil and injector power)
Black/ white wire to 12+(sensor power)
and white/ blue wire to 12+(ECU Power)

When I crank the engine over I am not getting any pulse from the leading coil signal wire(Green/yellow).


Am I missing something obvious here?

Thank you for any insight.

 

To check the G/Y wire you would turn the engine over by hand (rotate the alternator pulley) w/key to on and the signal on the G/Y wire would go from 0 volts to 5 volts briefly before going back to 0 volts.

 

Weird when I pulled the engine everything worked.

The leading coil signal wire, trailing coil signal wires and the injector signal wires are not getting any pulse from the ecu. (turning the engine by hand or using the starter)

The Ecu took a dump on me or I am missing something simple here.. I wired up my turbo II harness without any problems and my haltech wiring worked without any problems..

The ecu ground wires are making good engine grounds
W/L has power right at the ecu plug
B/Y has power
B/W has power

There isn't something simple im missing like a clutch switch or a nutral switch?

I'm stumped!

 

Check the Brown/White wire w/key to on the TPS or Boost/Pressure Sensor. Should read 5 volts. This will tell you if the ECU is powered properly and that the sensors are not shorted out.

 

Thank you for the insight.. I checked Brown/white wire at the tps and the map sensor and they both read 4.25 volts with the system turned on.

I even switched out the CAS just in case with no change in results.

Oh well it was worth a shot.

Thanks again!

 

So I pulled the harness, unwrapped the whole thing. I removed all unused wires and checked all other wires. Everything seems to check out.

chasing wires is pretty simple. So my bet is on the ECU..

 

You can connect an LED to the ECU to see if it is firing the trigger signal. One LED wire to pin 3I which supplies the ECU w/voltage w/key to start and on and the other LED wire to one of the primary injector pins. W/key to start the LED should flicker.

 

I do not get any trigger signal from any of the coil or injector wires coming from the ECU.
I swapped the ECU with a different one with no change in outcome.(Unless the 2nd ECU is faulty)
I also checked the CAS at the ECU plug and got close to 155 Ohms at both terminals.

I would like to wash my hands of this problem, But my curiosity of what is wrong with it is driving me crazy.

 

Is the ECU powered w/key to start or key to on or both?

 

For testing reasons I have it powered directly from the battery.