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Thread: How I Installed: AEM EMS4 standalone wiring with stock gauges and accessories

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2014-11-25 22:13:34
How I Installed: AEM EMS4 standalone wiring with stock gauges and accessories
I had quite a few questions about my G20 with the AEM EMS4 standalone so I figured I would document the second install. My brothers car is a 1999 Infiniti G20 with a Avenir engine, 6 speed and Garrett GTX3071R. Originally a automatic car. The wiring should be the same for the Sentra guys also. Please hang with me while I add, edit and get pictures uploaded to my work server. If you have any questions or suggestions please PM me.

This wiring will keep the factory gauges functional (Speedo/Tach/Low Oil/Water Temp/Fuel Level) and delete the factory ecu and related wiring.

First off it's best to grab a spare harness from a junkyard so you can take your time with the project. Not required, just a tip.

The harness splits in half. #1 The ECU side / #2 The Alternator to relay box side. They are conneted together with 2 large green color connectors. The #2 alternator side is what we need to split open and clean up.

Picture of the full OEM harness

Picture of #1 ECU side harness

Picture of #2 Alternator to relay box side harness

Starting with the #2 Alternator side. Strip the ties, looming, tape so you can pull the starter to battery cable away. There are only 2 wires that are useful to us that connect the two parts of the harness. The AC compressor switch (Blue with red stripe and the clutch neutral safety switch (Green with orange stripe). I deleted the automatic wires that go into the relay box (dark grey 8 pin connector.

Connectors needed: Water Temp (1pin purple) Low Oil (1pin yellow) Speed VSS (2pin Black/Red) Starter Enable (1pin black) AC compressor (1pin Blue/red stripe)

Picture of the harness before wiring was deleted

Picture of #2 alt/relay harness finished:

Harness #1 ECU Side:

You need the firewall boot..... That's right all of the sensor wiring is connected through the Alternator to relay control box (body harness) except the neutral saftey switch and AC switch.

I suggest that you save the shielded sensor wire for later use: picture below

The setup:
We are going to use a standard 8 pin distributor (Avenir W11 for DE engines or P11 SR20VE for VVL engines same connector), 4 GM D585 LQ9 Coil near plug setup (You could also use P12 or S15 coils), GM water temp and Intake Air Temp, Nissan factoy TPS, VVL solenoids, Mac 12v 3way boost control valve and AEM 3.5bar manifold pressure sensor.

And things we won't have: Idle air control, EGR .....

The only reason for cutting out the IAC was for a cleaner engine bay and we will use the throttlebody screw and EMS4 timing for idle control.

Picture of Avenir and P11 VE 8pin distributors:
Avenir-Left P11VE-Right

AEM EMS4 Install:

I am using the following parts for the AEM EMS4 Install:

Parts used in this project:
AEM EMS4 - 30-6905 -----------------------Prices vary $600-$750 (Check amazon.com)
AEM 120" Full Harness Kit --------------------------- $150 (PM me or check ebay)
AEM 3.5 bar MAP - 30-2131-50 ------------------------ $64 (Check amazon.com)
AEM Wideband 30-4100 -------------------------------- $160 (Check Ebay)
AEM SR20 CAS Disc - 30-8760 ------------------------- $33 (Works in all DE/VE FWD) (Check amazon.com)
GM Coolant Temp 12146312 3/8" NPT (BWD WT3000) -$13 (Oreilly,Autozone,Ebay,Amazon)
GM IAT - 25036751 3/8" NPT (BWD - WT382) --------- $15 (Oreilly,Autozone,Ebay,Amazon)
GM LQ9 (D585 coils) (4x required) ---------------------- $13 to $31 each (Aftermarket vs OEM) (Ebay)
Mac 35A-AAA-DDBA-1BA 12v 3 way valve -------------- $30 (For boost control) (Ebay

Salvage parts from original harness or elsewhere:

TPS 3pin connector -------------------------- Original Harness - Junkyard
IAC connector ------------------------------- Original Harness
Distributor connector 8pin *Avenir or VE --- Junkyard / Maxima V6 engine or 99' G20 ABS
GM Coils -------------------------------------- PM me New - Junkyard GM LQ9 trucks
Injectors -------------------------------------- Original Harness - PM me for new EV6 series
VVL Solenoids -------------------------------- Junkyard - #1 G20 knock sensor #2 solenoid not found yet
GM Coolant ----------------------------------- Junkyard - Most GM cars
GM IAT ---------------------------------------- Junkyard - Most GM cars
AEM MAP -------------------------------------- PM me New - Junkyard - Most GM cars

Picture of the EMS4, Distributor with cas disc installed, and 3.5 bar map:

Picture of the 120" Harness kit:

Starting the engine harness:

Picture of salvaged connectors
TPS Connector
TPS - IAT - MAP - Coolant
Fuel Injector - EV6
Complete Engine Side
GM LQ9 Coil Connectors

GPIO Configuration

GPIO1 - Fuel Pump - I set the fuel pump prime to 8 seconds
GPIO2 - Radiator Fan 1 - I have this wired to both fan realys - Turns both on high same time
GPIO4 - Vtec - I have the RPM switch @ 4200 RPM
GPIO6 - Boost Control - To boost solenoid
GPIO8 - Tach - You don't assign the output for anything, leave it blank. Go to Tabs\Hidden tabs\Tacho-Speedo and assing a GPIO there.
Main EMS4 harness - engine side

Main EMS4 harness - interior side

Alternator & stock sensors harness

Tach wire - GPIO8 to Cluster pin #16

Cooling Fan - Fan1 & Fan2 Relay
Last edited by Y2KG20 on 2014-12-23 at 22-01-43.
2014-12-19 14:31:42
AEM EMS4 standalones are on sale @ Amazon.com for $657.94 shipped right now. That's a pretty good deal!
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