Document # 31-0008
LM2_Manual_1.4.doc
42
6.8 Attenuating a Tach Signal
The problem of an erratic tach signal happens if there is a lot of ringing at high voltages.
To counteract this, it is sometimes necessary to attenuate the tach signal by about 30dB
or so. This is accomplished with a 100k variable potentiometer which can be purchased
at Radio Shack or any electronics store.
Wiring
1. Connect the tach signal to terminal A.
2. Connect terminal B to the tach signal input of the LM-2’s analog cable which is
the Black wire with a White stripe.
3. Connect the terminal C to Ground. (Do not connect this to the Blue tach signal
ground on the LM-2’s analog cable.)
Tuning RPM
1. Turn the pot all the way to the right (until no RPM is registered).
2. Start turning the pot to the left and stop when you start registering a tach signal
and the LM-2 displays an 'R' on the status bar.
6.9 OBD II connection diagnostic trace
In the rare situation where the LM-2 is not able to connect to the vehicle’s OBD-II
protocol creating a trace file will greatly aid in diagnosing the problem.
1. Press and hold the
Mode
button to go into the Configuration Menu Screen.
2. Select
OBD-II
and press the
Enter
button.
3. Use the
Arrow
buttons to scroll down to
Start Trace File
and press the
Enter
button. A 't' will alternate (or stay steady) in the "O" spot on the status bar.
4. Connect the LM-2 to the vehicle’s OBD-II port. Wait one minute.
5. Wait one minute, then either press
Record
to stop, or select "Stop Trace File"
from OBD-II menu.
6. A file named OBDIIxx.TXT will be saved on the SD card (xx counts up to 99).
7. E-mail this file along with the year, make, and model of the vehicle to the support
staff at Innovate Motorsports.
