Flex Fuel Installation Guide For VQ37

For 370Z, G37, & Early Q Series

Naturally Aspirated
Use our Flex Fuel kit – Since the car has to be tuned, it will have EcuTek. If the Bluetooth adapter was purchased, it can show ethanol content once this feature is turned on in the tune. An E% gauge is not required, but the customer can choose to install one if they prefer or if they don’t use the EcuTek BT adapter and app. Our new kits have been updated to use the Fuel-It! Bluetooth Analyzer so you can monitor ethanol content using the Fuel It! app.


Boosted [Turbo\Supercharged]
Use our Flex Fuel Kit without the Nissan OEM provided fuel hose assembly – Since the car is boosted, it is assumed the customer is using a CJ Motorsports or Fast Intentions fuel supply kit. In this case, there is a fitting just after the fuel filter that will be disconnected, and our Flex Fuel sensor will be attached at this location using the provided AN fittings. An E% gauge is not required, but the customer can choose to install one if they prefer or if they don’t use the EcuTek BT adapter and app. Our new kits have been updated to use the Fuel-It! Bluetooth Analyzer so you can monitor ethanol content using the Fuel It! app.
Note: With either Boosted application, a minimum of 1050cc injectors is required. These will provide enough fuel for about 650-wheel horsepower.


CAN Flex
Our CAN Flex setup allows for both analog and CAN communication to the ECU. If you prefer the original installation that hi-jacked the evap pressure sensor input, this will still allow you to do so. The benefit of the CAN installation is that it does not hi-jack any emissions equipment. The wiring on the CAN Flex consists of 5 wires. Red is 12v switched, black is ground, brown is CAN Lo, green is CAN hi, and blue is the analog 0-5v output which would NOT be used in a CAN installation. Vice versa, if you use the analog installation the two CAN wires would NOT be used.

For CAN Installation:
The CAN wiring needs to be performed at the VVEL side of the ECU. Going directly off the ECU will NOT
work. This will require removing the battery cover and windshield cowl on the passenger (right) side of
the car.


This is the connector that needs to be removed and where the CAN wiring will be performed. The
latch needs to be released, pull up on the latch using a pry tool and be gentle as you lift up. Once it’s
unlatched you can pull it away from its connector.


These are the two CAN wires where brown wire from the CAN Flex will tee into the yellow CAN LO wire and the green wire from the CAN Flex to the CAN HI green wire. See below for the pin out.


This is the wiring side of the connector you will pull out if you need room to work. Pin 4 is a black wire and goes to the black wire on the CAN Flex, pin 16 is a yellow wire and will go to the red wire on the CAN Flex, pin 23 is a yellow wire and will go to the brown wire on the CAN Flex, and pin 24 is green and will go to the green wire on the CAN Flex.


For Analog Installation (disregard if you are CAN install):
The content signal wire is the blue wire from the CAN Flex and connects to pin 102 or 121 (see diagram below for which wire to use). You will cut\sever this wire. Do NOT “tee” into the wire! It is critical you do this otherwise you have two input signals going to the ECU.


This diagram is for 2009-2018 370Zs, 2009-2013 G37s, 2014-2015 Q50, 2014-2016 Q60 ECUs The above diagram is when you’re looking at the backside of the connector, with the wires coming out. Note the small far right image with ‘H.S.’ which stands for Harness Side. When you count your pins, make sure you’re counting from the side of the harness with wires, not the pin hole side.


This diagram is for 2019-2021 370Zs ECUs The above diagram is when you’re looking at the backside of the connector, with the wires coming out. Note the small far right image with ‘H.S.’ which stands for Harness Side. When you count your pins, make sure you’re counting from the side of the harness with wires, not the pin side that goes to the ECU.


12v Red Wire:
For the red wire (12v switched), on the same connector where you wired the blue wire, you will carefully “tee” into pin 125 on the early ECU and use pin 145 for the 2019+ ECUs


Ground bolt location is located below the BCM right by the carpeting and floor mat. Connect this to the black wire on the CAN Flex.
In final there is a completely optional 3- pin sensor connector separate from the flex fuel sensor connector that can be used as a pressure input like fuel, oil, or coolant pressure to be used to integrate to the sensor for additional data logging. See below for image of the connector. The sensor & 90-degree adapter can be purchased from us. It is a GM pressure sensor.


EcuTek Tune Settings for Flex Fuel Sensor