LM2 setup for an accurate reading on scanner

[PLP]

Hi all
Have been playing with my lm2 through my eio and have followed lots of info here but have consumed way too much and now my head is spinning.

I have set the data as per the various excel spreadsheets (using lambda) and it appears accurate sometimes and then other times not so accurate. I then play with the offsets to get it accurate again, but what I'm finding is it may be accurate at 14.7, but richer or leaner it starts to drift each direction.
I have just been reading about connecting an earth wire from terminal 5 on the eio plug and connecting it directly to the battery, and from what I can gather reading other posts, it would be wise to power the lm2 directly from the battery also, rather than using the cig lighter socket which is what i have been doing so far.

I have also read about some of you getting a reference voltage (??) from the air con and using different pids in a formula, this is where I'm now getting confused.

I'm trying to log the LM2 to give the similar reading on the scanner to the hand unit itself.
From there I'm trying to calculate lambda error based on the scanner reading compared to commanded lambda.

any help to what you guys have done to get an accurate reading would be great

Thanks in advance

[Ricardo]

Are you using the pro or the standard version?

[PLP]

sorry about that, I'm using the pro

[Ricardo]

I first did setup my scanner with the LM2 and was reading exactly the same as the unit.

You need the analog cable supplied with the LM2 and then use the output No1 (lime green and yellow wires)from that cable to the VCM scanner terminals 1(lime green)-5(Yellow).

In the scanner you have to insert a wideband for one of the EIO inputs (Bottom six lines of the table display). If you choose the the Preconfigured I/O for the LC1 it will be like same as the LM2.

[Speedkills]

Hey, did you resolve this issue? I have an LC1 that I just hooked up and HPTuners reads fine when my gauge is 14.7, but drifts off after that. For example, when the gauge reads 10.8, HPTuners reads about 12.3. I did use the yellow analog wire from the LC1. Any thoughts?

[jimmyblue]

Those Excel spreadsheets that want to calculate an offset are
bullshit. The "offset" is your ground loop voltage and it varies with
heater load, active accessory current that uses body sheet metal
for a return and so on. All that is variable. The only good approach
is an instrumentation amplifier. I've built a few little pods in this
vein, the latest being a 12V powered, isolated one that doesn't
need a pair of batteries. Costs about $10 in parts (if you have scrap
perfboard laying about) and an evening's worth of soldering. You
have to break the hardwired ground loop, there's no way around it.

Speedkills, you need to read back your LC1 transfer characteristic
and make sure the slope and offset match what HPTuners uses.
That error looks like what you'd get with a 0-5V on one end and
0-4V on the other, for example.

[R0G3R]

I'm having trouble with my LM2 too..it reads different in the hpt screen

[Ricardo]

Speedkills:
I am quoting these two extracts from the LC1 manual:

3. LC-1 Cable connections:

Interface and power cables with 6 stripped ends*:
a. Red 12V supply
b. Blue Heater Ground
c. White System Ground
d. Yellow Analog out 1
e. Brown Analog out 2
f. Black Calibration wire

As factory programmed the first output simulates a typical narrow band oxygen sensor. The second output is programmed to output between 0 V for an AFR of 7.35 (gasoline) and 5.0V for an AFR of 22.39. Other curves of course are easily programmable

If you have a gauge with your LC1 and its hooked to the brown wire (analog2) the gauge will be accurate.

If you used the yellow wire from the LC1 to your scanner you have to reprogram its output using the LM programmer with the same values as found in analog output 2. From the factory it is programmed to mimic a narrowband.

[Ricardo]

ROG3R:
Same here for the LM2:

Analog Cable
The provided analog cable has 14 stripped ends. The wire assignments are as follows:
Analog Out 1 + (Lime Green)
Analog Out 1 – (Yellow)
Analog Out 2 + (Brown/White)
Analog Out 2 – (Dark green)
Analog In 1 + (Purple)
Analog In 1 – (Black)
Analog In 2 + (Grey)
Analog In 2 – (Brown)
Analog In 3 + (White)
Analog In 3 – (Red)
Analog In 4 + (Peach)
Analog In 4 – (Orange)
RPM + (Black/White)
RPM – (Blue)

Factory Programmed Defaults:
Single Channel A/F units: Analog Output 1 is programmed to output between 0 V for an AFR of 7.35 (gasoline) and 5.0V for an AFR of 22.39. Analog Output 2 simulates a typical narrow band oxygen sensor. The configuration is 1.1 V for an AFR of 14 and .1 V for an AFR of 15.

You have to use Output No 1 from your LM2 (Lime green and yellow) to feed it to the scanner (pro version) Terminals 1 and 5.
Make sure you select an LC1 wideband from the preconfigured I/O in the scanner table. (Dont choose an LM1-it has different output and will cause a drift in your recordings)

[R0G3R]

Okay ill try that..thanks for the tip

[JVK]

Let us know how you go ROG3R ,Keen to hear the results from Ricardo's info.

[R0G3R]

Okay, its still reading off compared to the lm2 screen

[streetperf]

I have the dynojet wideband, can't get it to work with the scanner(needle won't show). I'm thinking of purchasing a AFR gauge and run it that way. Is that something that is feaseable or am I wasting time and money. Seems to me, and I'm new at this, there are alot of problems, and misgivings on getting this programmer to operate.
Any advice would be helpful,

[NHRA-TA]

hey! guys with the LM2 if you make a custom EIO input 1 for +10/0.5 and program your analog output 1 in your LM programmer for 0v=10 and 5.0v=20.It works almost perfect.Also set your advance output setting to 1/12 response speed.

[novaracer]

I hate my lm2 i cant get the thing to read the same as the scanner. i will order a new wideband and this thing will burn in my fire pit. big waste of money never again innovate. i just want a plug and play easy hook up.

[lpfeifer1980]

Was having troubles setting LM2 up but this helped resolve my issue.