Linkg4+ Atom no longer registering to Cranking

[Blair Westoby]

I am running a g4+ Atom on my 13bt, Was working fine a week ago, now it no longer responds when i go to start car.

It turns on as usual and does the usual fuel pump prime, But during cranking i am getting nothing, no spark or fuel.

I went straight to Crank angle sensor to find the insulation on the wires at the CAS had pulled apart and the bare wires were touching. I rewired the plug for CAS and am getting the correct resistance reading back at the Ecu but has not fixed the issue!

 

Any ideas what else could cause issue?

[Simon]

ECU wise the RPM can be locked out for the following conditions.

ECU not unlocked

ECU hold power active

Dual ECU active

Anti theft active

Battery voltage above limit

And of course bad crank / cam signals.

[Blair Westoby]

Nothing its Locked out. It was going fine a week ago.

Signal is fine right up to the Plug to Ecu.

Under Trigger Status im get Signal for Trigger 1 But not trigger 2 So i am loosing that signal somewhere from the Ecu plug onwards.

[Simon]

Next step will be to Scope the trigger at the ECU end to see how good the signal is.

[Blair Westoby]

Removing wiring from car is to differcult but I sent ECU and CAS to Link to check.

ECU was working fine and they Scoped CAS and it too is working correctly.

I again did a continuity test on wiring and it still looks fine, 

[sardengineering]

It's great that you had the CAS and ECU tested, but as Simon indicated the best follow-up solution would have been to leave everything as is and test the signal coming in to the ECU on Trigger 1 and Trigger 2. The will allow you to see exactly what the ECU is seeing. From there it should be easy enough to arrive at an absolute conclusion, especially since the ECU and CAS has already been tested. Of course, this would have been another follow-up step but you've already taken care of this.

Please note that the wiring harness doesn't need to be removed to test the Trigger 1 and Trigger 2 signals coming in to the ECU with an oscilloscop.

Hope this helps, cheers!

[Blair Westoby]

That would be a ideal solution to test the wiring with a Oscilloscop, but i don't know of anyone that would have one that could come round and test the wiring for me. It is essentially three wires with nothing wrong with them. I even tried bypassing the wires with some new ones and still no luck. Pretty confident that the wiring is not the problem and it is something that has happened over night suddenly 

[sardengineering]

I am sorry that my advisory was less helpful than you would have hoped for but this is really the best approach. I wish that you were using one of the Link ECUs which has the built-in trigger scope which can facilitate the results an oscilloscope can provide. If the ECU has been tested to be okay, and the cam angle sensor has also been tested okay then you can try wiring the cam angle sensor to the ECU outside the original harness. Switch off the various actuators such as fuel pumps, fuel injectors, ignition output channels and the likes then crank the engine over viewing the run time values (press R). Things to note would be sensor status and any activity on the trigger 1 and trigger 2 inputs. Hopefully this will give some indication of what is happening.

My apologies for responding with a less than ideal proposed solution but this is the best I can come up with for the time being, hope this helps you.

Cheers!