Technical Electrical problem - engine dies

[dukeofdream]

Hi all. I have a very weird issue... Engine will suddenly die, radiator fan kicks in even when the car is cold and i'll get a bunch of DTCs...

P0201 - injector 1 open circuit
P0202 - injector 2 open circuit
P0203 - injector 3 open circuit
P0204 - injector 4 open circuit
P0033 - BlowOffValve - open circuit
P0433 - EVAP valve - open circuit
P0135 - Lambda sensor 1 - open circuit
P0141 - Lambda sensor 2 - open circuit
P0243 - WasteGate valve - open circuit

Problem started around 3 months ago and left me on the street... I brought the car to a shop that couldn't figure it out and after a week i went to get the car as is. I studied the eLearn trying to find something in the very poor electrical diagram. I was searching for a junction D004(1c on the picture) and lightly pulled on a bunch of wiring. Didn't find the junction but tried to start the car anyways. It fired right up, all the DTCs gone. Fast forward 3 months to today. I swapped the cams for the 150hp ones and changed the valve oil seals. After everything was put back together the car started and 30 seconds later it died giving me the exact same DTCs. I restarted it and it worked for a few minutes and then again the same... i moved a bunch of wiring again, checked all my fuses and relays. Car started drove for 500 meters and died again... Has anyone seen this before? Funnily enough all these sensors that suddenly went missing, have their pins one right next to the other on the ECU side (Picture 2)... ECU was checked and is fine. My guess is that it's a single wire that either provides 12v to all these sensors or its a common ground that only affects these... I really can't figure out from the diagram if the sensors have a constant 12v and the ECU is regulating the ground or the other way around. A common ground would make much more sense but i just can't find anything loose... Any help greatly appreciated

 

[Sylvester22]

I assume you've checked the battery voltage and clamps.
I don't know much about electronics, but I was told the earthing cable under the battery tray, that's a big one and it might fray overtime, plus check other earthing points. I've also read someone had a lot of electrical issues and it was the cable damaged by the gearbox, if you lift the cover and look inside you'll see a single cable connector near the top. Unfortunately that's all the info I got.

 

[ZaphodB]

I assume you've checked the battery voltage and clamps.
I don't know much about electronics, but I was told the earthing cable under the battery tray, that's a big one and it might fray overtime, plus check other earthing points. I've also read someone had a lot of electrical issues and it was the cable damaged by the gearbox, if you lift the cover and look inside you'll see a single cable connector near the top. Unfortunately that's all the info I got.

Engine metalwork back to the -ve terminal is crucial for any car,
Exposed braided earth cable has more surface area to rot the copper away slowly but steadily.
That and the connections on this cable are the first thing to closely scrutinise. (or just replace cable and remake all connections.)

 

[dukeofdream]

I checked all the fuses, relays, verified I have good 12v power going in the ecu by taking apart the plug and measuring with a multimeter while the engine was running… I did not get any voltage drop during the time it failed… I also checked all 3 earth lines going in the ECU with the same method and even used a light bulb to verify that the connection is good. I ordered a new ECU to test out but I really doubt this could be the problem Frustration level over 9000

 

[Sylvester22]

I checked all the fuses, relays, verified I have good 12v power going in the ecu by taking apart the plug and measuring with a multimeter while the engine was running… I did not get any voltage drop during the time it failed… I also checked all 3 earth lines going in the ECU with the same method and even used a light bulb to verify that the connection is good. I ordered a new ECU to test out but I really doubt this could be the problem Frustration level over 9000

Check that single cable around gear stick cover, I've mentioned above, occasionally it may rub against the gear stick and causes open circuit.
It's frustrating for sure, had an issue where the engine would suddenly die after few min of driving, turned out the ecu was fried as they didn't seal it properly after ecu tuning, done by prev owner. But yours test good so probably that's fine.

 

[ZaphodB]

My guess is that it's a single wire that either provides 12v to all these sensors or its a common ground that only affects these... I really can't figure out from the diagram if the sensors have a constant 12v and the ECU is regulating the ground or the other way around. A common ground would make much more sense but i just can't find anything loose... Any help greatly appreciated

You should be able to confirm with continuity whether it's a common ground by metering for continuity between the different sensors (possibly to avoid mis-reads with the sensor disconnected whilst testing), if it turns out (absolutely conclusively !) to be a common ground then make a temporary secondary ground and re-test.