Lm2 wideband jumping reading

[wa11ace]

Hi im setting up my 3.2 scanner. And add my lm 2 wideband. The problem is the reading on my scanner is different from my wideband. My wide band sits on 14.2 and my scanner jumps 14 to 15 so fast i cant even read it. Has anybody else came across this?? Thanks

[wa11ace]

Bump. Can any body help.

[schpenxel]

Post a log.

Where are you looking at the reading in Scanner? Gauge, chart, graph, channel?

You can use the "filter" feature for charts and gauges to sort of slow the reading down.

Try something like 250msec and see if that's any better

For the difference in WB gauge vs. Scanner, the simplest way is to change the offset value in the transform for that input. Not perfect but should get you close.

[mowton]

When wiring the LM-2, because it has open ended, differential outputs, grounding is key. Also, I have heard of issues with cigarette lighter wiring in newer cars (not really a cigarette lighter) not being up to the task of supplying the up to 6 amps (O2 heater and controller load) cleanly (voltage drops) so a good power connection from the battery to the controller is a good idea. Build a cable from 12-14 awg. wire and twist it if you can (helps reduce common mode noise). Add a SPST switch in series with the 12vdc line to the socket so you can turn the unit on and off. Remember to preserve the live of the sensor, you should fire up the vehicle first, then turn the LM-2 on. Use a cigarette lighter socket so you can plug the LM-2 power cord directly to it...or any wideband for that matter. This power source enhancement is a plus for all units.

From the MPVI pin 5, run a wire (14 awg) direct to a hard ground like the negative terminal of the battery or a good bolt on the firewall. If you made the above power cable, then tie direct to the sockets ground lug.

While a little more difficult, if you can, tie the sensor ground to th the LM-2 to the socket as well.

The above will make the socket the merge for all the ground current to carried back to the battery (depends which current flow theory you prescribe too :-)) which is acceptable. The best approach to nullifying ground loops is to "home run" all the grounds back to a common source but that is a lot of extra work and wire. Go with the above. Make sure all you connections are solid and soldered well.....no twisting together here....

Lastly if you open the wideband parameter setting table in the Chart, you will see a filter with a box marked ms Try setting it to 50-100 ms and see if it stabilizes the signal any.

Ed M