I just discovered that, unlike the oxygen sensors, the coax wire used for the Crankshaft Position Sensor and the two Knock Sensors uses coax wires with two wires inside the shielding. (Oxygen sensor coax wire only has one single wire inside the shielding)

I'm rebuilding this harness from scratch, is there a benefit to using two individual single coax lines for the positive and negative signals? Do the positive and negative wires interfere with each other in anyway?

Second question, can I use the same double coax wire used for knock and CKPS and then split up at each pair of oxygen sensors? They are right next to each other.

I wonder why they deemed it ok to run a pair of shielded wire to the CKPS and Knock Sensors, but not the oxygen sensors.

Thanks!

 

I am not sure what type of sensor Jaguar used on the AJ16 but I would expect it to be a VR not a Hall.

VR sensor will have 2 wires/pins and Hall 3.

The reason for using coax with 2 conductors is noise suppression. On a VR sensor each conductor will go to one pin on the VR sensor and the shield will be connected to chassis ground at the ECU end ONLY. The shield then becomes a GUARD and because it 's connected at ONE end ONLY no current can flow, this significantly reduces induced noise into the cable.

VR sensors generate a spike like pulse which the ECU can not trigger on, so the ECU needs to have circuitry to condition the signal so the ECU can trigger on a pulse edge. SO any noise spikes can add additional triggers which is not good.

Knock sensors are even harder because the ECU is listening for a specific signal and ALL noise needs to be filtered out, or the ECU could mistake this noise for knock and retard the ignition.

So to answer your question as long as you use shielded cable you should be fine. You can buy coax with dual centre conductors, sometimes called Twinax.