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Wiring an aem wideband gauge with bosch wideband sensor to Link g4+ plug in ecu

EFI Wiring Fundamentals

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hey guys ive been looking at different diagrams to wire in the wideband sensor but I’m struggling to find the correct info. I have no o2 sensors in my car and when I plug in the laptop I don’t have any lambda reading so I wanted to add the aem gauge and the Bosch sensor it comes with to monitor my gauge while driving and have the wideband run in closed loop function! Can I wire it to my primary o2 wiring as I don’t have a sensor or should I use an unused analog channel? Also I’m a bit confused as it needs to be wired to a heater etc, can attach diagrams for reference, any help will be appreciated

What model car & ecu are we talking?

Link g4+ extreme plug in for evo 9

G'day Alastair.

You'll need to give your AEM Gauge power and ground, and it'll have come with a harness that connects to the bosch sensor. The gauge controls the sensor heater, not the ECU.

To connect it back to your ecu, you'll need to connect the 0-5V signal output wire of the gauge to an analogue input on the ECU. Yes, you should be able to use the OEM O2 sensor input wire for this if its in a convenient place, or you could modify your OEM loom and connect it at the header plug. Another option would be to purchase a Link XS expansion loom that you fit inside the ECU to get access to the rest of the analogue inputs, but if you're not using the o2 sensor input at the moment, it'd be easier to wire it to this as it wont involve opening up your ECU.

When you supply power and ground to your AEM gauge, try to give it a ground connection as close as possible to the point your ECU is grounded too (typically the vehicle body, close to where it is mounted), as this will help with voltage offset issues giving you different lambda readings within the ECU to what your gauge is showing.

Have a look through this:


Looks like the original front O2 sensor is connected to analogue input 4, so if you wire the 0-5V output of your gauge to the OEM wiring, and reconfigure the calibration on analogue input 4 to match the calibration of the AEM gauge (presumably in their documentation somewhere), you should be able to get it up and running.

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