oversteer Posted September 10, 2019 Report Share Posted September 10, 2019 Hello I'm installing the wires and adding the plugs for the 2 lambda sensors and I have just realised that the Link wants all 6 wires connect to the sensor.... I've run 5 as I looked at the link wiring table and it listed 5, and some of the wiring I'm using came from a MoTeC install, which only uses 5 wires ! Anyway, I now need to run that 6th wire which is "Ignition switched 12v", is it wise to use the ECU's 12v power supply for this ? In this case the ECU is power via the original Subaru wiring "Control module power supply", or would it be better to add another circuit/relay and fuse for the 2 lambda sensors 12v? Cheers Quote Link to comment Share on other sites More sharing options...
cj Posted September 10, 2019 Report Share Posted September 10, 2019 the sensors can draw up to about 8amp each during heating phases. if the fuse behind that factory wiring is say 20 amp then its fine. if its a 5 or 10 amp fuse, you will probably pop it Quote Link to comment Share on other sites More sharing options...
oversteer Posted September 10, 2019 Author Report Share Posted September 10, 2019 FSM says it has a 30amp fuse which runs ECU, a bunch of sensors and solenoids no longer connected and the injectors... searching this topic i did come across something about don't power lambda(might have been can lambda) shared with any inductive load(injectors).... Is that still the case with powering lambda sensors ? Quote Link to comment Share on other sites More sharing options...
Brad Burnett Posted September 10, 2019 Report Share Posted September 10, 2019 I had this conversation with a link tech guy yesterday. I have attached the 12v supply for the lsu 4.9 to the link power supply on the A connector. Quote Link to comment Share on other sites More sharing options...
Richard Hill Posted September 10, 2019 Report Share Posted September 10, 2019 It should be fine, the bosch controller current limits during the heating phase to a maximum of a couple of amps Quote Link to comment Share on other sites More sharing options...
cj Posted September 10, 2019 Report Share Posted September 10, 2019 1 hour ago, Richard Hill said: the bosch controller current limits during the heating phase to a maximum of a couple of amps Is this something you've measured? the spec sheet for a couple of the lambda controllers for 4.9's (inc link's can-lambda) say max 8amp during heating. It wouldn't be the first time a spec sheet has been over-zealous with its safety margins so i'd love to know the real world number. I should go put an amp clamp around one myself.... Quote Link to comment Share on other sites More sharing options...
Richard Hill Posted September 10, 2019 Report Share Posted September 10, 2019 I have monitored the current draw of CAN lambdas during heat up phase several times from ambient, using low voltage (10 Volts and nominal Voltage 13.8) Basically on the edge of failure mode, The maximum current they draw is 1.5 Amps (worst case at low voltage) . reducing down to about 1 Amp when up to temperature. I will post the Thunder current draw tomorrow when I can dig the values out. cj 1 Quote Link to comment Share on other sites More sharing options...
Richard Hill Posted September 10, 2019 Report Share Posted September 10, 2019 Also, internal lambda controllers in G4+ ECUs don't have a problem being near inductive loads (such as injectors and ISCVs) HTH, Richard. Quote Link to comment Share on other sites More sharing options...
Richard Hill Posted September 12, 2019 Report Share Posted September 12, 2019 Here are some measurements from a single 4.9 Lambda sensor running on a Thunder on the bench. The maximum the sensor drew was 1.43A at the end of the heating phase Slowgti and cj 1 1 Quote Link to comment Share on other sites More sharing options...
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