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Modifications to my wiring loom!


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So I've currently got my ecu and engine bay harness out of my car which is running a link G4. Going to make a few modifications to it, I've never really played with engine wiring so not 100% sure I'm correct in what I'm thinking so just want to check 

Im going to put a Wideband 02 sensor in the exhaust instead instead of using the factory one. Is it possible to wire a bosch LSU 4.9 straight to the ecu instead of using a can lambda module or not?

Im assuming I won't be able to do this and I'll have to use a can lambda? In that case, I will use the factory lambda 12v for the can lambda module and run 2 new wires from the ecu to the can lambda module. Do these 2 new Canbus wires need to be twisted together and shielded from the rest of the loom or just twisted?

Im also adding fuel pressure and oil temp/pressure sensors. I haven't yet specced the sensors, but I think they all work in the same way? Am I correct in saying that all they require is a signal cable to the ECU and the sensor wothh ground itself? And does it also require a sheild cable or not? If it does require a sheild, is the metal braided style shielded cable good enough? And the braiding earthed to the chassis at only the ecu end? I'm also going to just wire one of these sensors to the signal for the lambda sensor. That should work shouldn't it?

When I installed my ecu I changed from MAF sensor to IAT sensor. I used 2 of the 3 cables from the MAF sensor. At the time I didn't extend the sheilding as the wires didn't run near any other cables. However now I'm running them in a different direction near other cables, do I need to extend the sheilding on the iat wires? I've included a picture for reference

Also, the start cable for my AC Compressor and the cables for the AC pressure switch have been cut. From looking at drawings the ac compressor start cable comes from the ecu, does it go through a relay or is it straight from the ecu? It's a struggle to tell!

I also can't find any info as to where the cables from ac pressure switch go so any info regarding that would be very much appreciated thanks!!
 

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2 hours ago, Aseddon said:

Im going to put a Wideband 02 sensor in the exhaust instead instead of using the factory one. Is it possible to wire a bosch LSU 4.9 straight to the ecu instead of using a can lambda module or not?

No, you will need a wideband controller as well.  This doesnt necessarily have to be a Link CAN lambda, there are many 3rd party 0-5V analog and also 3rd party CAN options, but the Link CAN Lambda does work well.

 

2 hours ago, Aseddon said:

I will use the factory lambda 12v for the can lambda module and run 2 new wires from the ecu to the can lambda module. Do these 2 new Canbus wires need to be twisted together and shielded from the rest of the loom or just twisted?

The CAN wires need to be twisted but dont need to be shielded.  They are fine bundled along side other wires. If using a Link CAN lambda you will need a 120ohm terminating resistor across the two CAN wires near the lambda connection and I would also install the 22uF capacitor across the power wires as per the quick start guide since you arent using a dedicated relay.

 

2 hours ago, Aseddon said:

Im also adding fuel pressure and oil temp/pressure sensors. I haven't yet specced the sensors, but I think they all work in the same way? Am I correct in saying that all they require is a signal cable to the ECU and the sensor wothh ground itself? And does it also require a sheild cable or not?

Pressure sensors are 3 wires - 5V, sensor ground and signal.  They donot need to be shielded.  You can often splice into the 5V and ground to the TP sensor or MAP sensor.

 

2 hours ago, Aseddon said:

When I installed my ecu I changed from MAF sensor to IAT sensor. I used 2 of the 3 cables from the MAF sensor. At the time I didn't extend the sheilding as the wires didn't run near any other cables. However now I'm running them in a different direction near other cables, do I need to extend the sheilding on the iat wires? I've included a picture for reference

No shield needed.

 

2 hours ago, Aseddon said:

Also, the start cable for my AC Compressor and the cables for the AC pressure switch have been cut. From looking at drawings the ac compressor start cable comes from the ecu, does it go through a relay or is it straight from the ecu? It's a struggle to tell!

I also can't find any info as to where the cables from ac pressure switch go so any info regarding that would be very much appreciated thanks!!

What model car is it?

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11 hours ago, Adamw said:

No, you will need a wideband controller as well.  This doesnt necessarily have to be a Link CAN lambda, there are many 3rd party 0-5V analog and also 3rd party CAN options, but the Link CAN Lambda does work well.

 

The CAN wires need to be twisted but dont need to be shielded.  They are fine bundled along side other wires. If using a Link CAN lambda you will need a 120ohm terminating resistor across the two CAN wires near the lambda connection and I would also install the 22uF capacitor across the power wires as per the quick start guide since you arent using a dedicated relay.

 

Pressure sensors are 3 wires - 5V, sensor ground and signal.  They donot need to be shielded.  You can often splice into the 5V and ground to the TP sensor or MAP sensor.

 

No shield needed.

 

What model car is it?

Massive help as per usual thanks mate! 

Its a Nissan s15 spec R JDM

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18 hours ago, Adamw said:

since you arent using a dedicated relay.

Is it reccommended to use a separate relay dedicated to the can lambda then? Do i just use the current lambda 12v as signal to the relay or should I use main ecu power as signal to the relay? 

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22 hours ago, Adamw said:

Pressure sensors are 3 wires - 5V, sensor ground and signal.  They donot need to be shielded.  You can often splice into the 5V and ground to the TP sensor or MAP sensor.

Is the temp sensor just a signal wire by itself or signal and ground too? 

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Stock lambda is 3 wire. 

12v power (I think its 12v and not 5. Should I check this or will it definitly be 12v?) and then 2 cables that come from the ecu, on the attached diagram they're numbers 19 (white, which appears to go into a black sheild ) and 111 (black with red stripe) I take it 19 is signal wire and 111 is sensor ground 

Im going to use the white as a pressure sensor signal and just use the black as ground for oil temp, oil pressure and fuel pressure and the brown for can lambda power. for my 2 pressure sensors I will take my 5v from a splice on the TP connector. 

Does the above sound all OK?

Apologies for the schoolboy questions I just don't want anything to be wrong before it's all sleeved lol

Cheers 

 

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