s14hunter

iTrader: (1)

This thread will outline how to use a Dakota Digital SGI-5E converter box to get the stock speedometer working on an S14 240sx with any LS swap using a stock GM pcm from 99-2007.
The SGI-5E is the newest box from DD. The old boxes have dip switches and are a major PITA. Save yourself a headache and get the SGI-5E.
After reading many different threads with half-assed information, I decided to clear things up for future swappers.
First off, the LS1 pcm outputs a 4,000 PPM DC signal on the Dark Green/White wire (pin #50 on the pcm red or green connector).
The S14 speedometer needs a 8,000 PPM AC signal to work properly. The difference between the DC and AC signal is why you need the DD box and can't just change the VSS setting in your PCM to 8,000 and call it a day.

Cluster Wiring:
There are two wires that run to the back of the cluster for the speedometer. One is Red and the other is Red/Yellow. You only need to use the Red/Yellow wire (pin# below) for the speedo to work. See the pictures below for the location of this wire on the back of the cluster on 95-96 and 97-98 cars. I pulled the cluster, snipped the R/Y wire and ran a new wire down to my DD box.
1995-96 = Pin# 28
1997-98 = Pin# 25

Wiring the DD box:
POWER: 12v switched ignition source
GROUND: Any chassis ground
SIGNAL IN: Dark Green/White wire from PCM pin# 50 on red or green connector
OUTPUT 1: Red/Yellow wire going to the gauge cluster (see pic below)

DD SGI-5E Setup/Calibration:
Follow the instructions for the DD box to set the mode to L-L
Then set the calibration to 2.00

PCM Setup/Calibration:
Open your tune file in HP Tuners (or have someone) and go to the "SPEEDO" tab (Red box in pic)
Then click the "Calibration" tab
In the "VSS Pulse / Revolution - Trans" box, input either 17 (for a T56) or 40 (for a TH350/400, 4L60/65/80)
Click the Edit tab and select the Gear/Tire Wizard
Input your rear differential gear ratio
Input your tire height in inches
(this can usually be found on your tire manufacturer's website or on TireRack)
Click Adjust
Flash the update to the vehicle and enjoy!


I have a 95 240sx SE with a Q45 differential (3.54 ratio), T56 trans and Nitto 555R 275/40R17 tires. I used a GPS speedometer app on my phone and verified my speed up to 85mph.

slowman

Nice work!

green_S14

great work s14hunter!

2muchboostNY

iTrader: (8)

Great write up bud thanks for the detailed info.

s14hunter

iTrader: (1)

My original write-up was sort of a band-aid, and I didn't know it until I got my HP Tuners cable. It made the factory S14 speedo show the correct speed, but the PCM would only read roughly half the speed I was actually going. I've updated the write-up with the appropriate details to get the PCM and S14 speedometer reading correctly.

Koukimonster240

s14hunter

iTrader: (1)

You will need to run a wire from Output 1 on the SGI-5E to the Red/Yellow wire on the back of the cluster that's pin# 25 on the M71 plug. See the picture below from the FSM. Setting the DD box to L-L and the calibration to 2.00 should be the same.

Koukimonster240

s14hunter

iTrader: (1)

I have updated the write-up with the 97-98 info. I didn't realize the 97-98 clusters were wired differently. Let us know Koukimonster if it works for you. If not, you may have a dead cluster

Koukimonster240

s14hunter

iTrader: (1)

My write up is for the newer -5E DD box. That's what I have in my car, and it works like a champ, it'll bury the needle and everything I added another picture to the original post of the wiring on the back of the cluster as well for the 97-98 cars.

Koukimonster240