Using EFILive (V5/V6) to capture Wide band O2 data
I recently bought an Innovate Motorsports LM-1 Wide band O2 sensor. The only problem is that I had to log data in the LM-1 as well as in EFILive. So I decided to use an existing sensor input into the PCM to output the LM-1 date into.
Below is a link to a Word doc that explains what I did to achieve this.
ftp://members.aol.com/jnorris404/EFILive_LM1.doc
Below is the text from that document minus the pictures.
Below is how I integrated the Innovate Motorsports LM-1 wide band O2 meter or any wide band that has an output range of 0V-5V into the PCM of a 98 Z28 using EFILive.
I am sure that this method will work for any 98 - 2002 F or Y body car. You will need to consult your service manual to confirm this.
If you have any questions or corrections email me at [email protected]
Thanks
John Norris
Preface
The goal is to pipe the analog output (voltage) from the LM-1 into the stock PCM and log it with EFILive as you are logging other data as well. I used the 0V-5V input into the PCM that is used to monitor the A/C Pressure.
LM-1
I used the analog output port number 2 as configured from Innovate Motorsports.
1V=10:1AFR 2V=20:1AFR.
The analog interface cable I used is part number 42-2561 from Radio Shack. You will need to cut the ¼ inch female end off and strip back insulation to expose the wires and copper shield. The shield is ground, the red wire will be output 2 and the white wire is output 1.
Ultimately you will be using the ground and the red wire to interface the LM-1 with the stock PCM.
PCM
Under the hood on the passenger’s side towards the back you will the pressure sensor for the A/C system. See picture below.
There is 3-wire plug attached to the sensor. On a 98 F body the red wire is the input into the PCM, the gray wire is the 5V reference voltage supply, and the black wire is the ground.
I ran the analog output from the LM-1 into this plug using wiretaps to connect to the red wire from the LM-1 to the red wire going the PCM and the black wires from the LM-1 to the black wire going to the PCM. I passed the analog output cable from the LM-1 through the rubber grommet located below and the left of the PCM
The A/C pressure plug must be unplugged from the sensor while you are using it to receive data from the LM-1. If it is not damage to the LM-1 or your PCM could result. Additionally the A/C will not function when the plug is not connected to the sensor.
EFILive
With some help from Paul (EFILive) I created the formula below which is based on the GM.ACP PID.
(RAW({GM.ACP})/5.1)-correction factor
The RAW function tells EFILive not to perform any calculations or conversions to the data for the specified PID.
GM.ACP – A/C Pressure has a range of 0-255 in its RAW state.
Dividing the GM.ACP PID by 5.1 is for the following reason.
The RAW voltage range from the PCM for the GM.ACP PID is 0-255 so 255/51 = 5. This converts the raw data to a 0V-5V range
The voltage range the LM-1 is going to output is 1V-2V so 1.47 will really be an AFR of 14.7:1. Remember on the LM-1 that 1V=10:1AFR 2V=20:1AFR
You would need to multiply the data by 10 in order to see the 14.7 value.
So 51 divided by 10 equals 5.1 the completed formula would be written as
GM.ACP / 51 * 10 which can be simplified and rewritten as GM.ACP / 5.1.
In order to log the wide band O2 data in EFILive you must select the GM.ACP PID as well as the new wide band PID you are creating.
Correction factor
For whatever reason the analog output from the LM-1 is not the same as the A/F value as logged by the LM-1. In order to make the values appear correctly in EFILive You will need to apply a correction factor.
What I did was to let the car idle for about 15 minutes and recording the A/F with the LM-1 as well as EFILive with no correction factor applied to the formula. Afterwards I averaged the A/F numbers from the LM-1and EFILive logs. The difference is the correction factor. I also did some WOT logging and the correction factor was inline with the correction factor as determined from the idle test.
When I measured the voltage on the red wire going to the PCM from the A/C Pressure with nothing else attached or plugged in there was a voltage floor of .02V. My correction factor was -.425. The formula I put into CALC.PIDS.TXT file EFILive was (RAW({GM.ACP})/5.1)-0.425. This file is located in the following directory “C:\Program Files\EFILive\ScanToolV6\Configuration”
Also when you re-calibrate the wide band sensor you will also have to confirm your correction factor is still correct. The first correction factor I used was 0.522. With a good correction factor in place when I compare the logged values from the LM-1 to the values logged in EFILive there is less that .1 difference.
The LM-1 will output the AFR even if you are not recording the data. So after you have determined the correction factor you will no longer have turn on/off the record button to get the data as long as you are recording with EFILive.
Below are the formulas in my CALC_PIDS.TXT file.
# Calculated
# ----------------
#Units Low High Fmt Expression
#------------ ------------- ------------- ---- --------------------------------------------------------------
*CLC-00-1000
V 10.0 20.0 .3 (RAW({GM.ACP})/5.1)-0.425
# ================================================== ============================
*PRN - Parameter Reference Numbers
# --------------------------------
#
# Calculated
# ----------------
#Code PRN SLOT Units System Description
#------------------------- ---- ------------ ---------------- ---------------- ------------------------------------------
CALC.WBO2 F600 CLC-00-1000 V Fuel "Wide Band O2 Sensor"
