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Recording sensor data through OBD2 or analog input?

Posted: October 8th, 2015, 8:18 am
by nicpaige
Getting down to the fine details now on my build and need to be prepared to do some data logging. I have experience with the Innovate LM-1 and hooking up the analog wires to the analog cable for the different 0-5v sensors. My question is with OBD2 and the new LM-2 data logger that has the OBD2 port plug, is it possible to get these readings through the OBD2 itself? Or is it still necessary to tap into the sensor wires of each one you want to log? Also where to pick up the rpm tach signal on my 2000 XJ? Does anyone have a cheaper solution than the Innovate? Thanks

Re: Recording sensor data through OBD2 or analog input?

Posted: October 8th, 2015, 10:16 am
by jeepxj3
The OBD port is CAN BUS data. I think you can data log it on Torque Pro.

Re: Recording sensor data through OBD2 or analog input?

Posted: October 8th, 2015, 5:10 pm
by SilverXJ
The OBD 2 port on the XJ can get the RPM reading. I am unsure if the LM-2 would get the readings from that, but since it does connect to the OBDII port it probably does.

To pick up a tach signal directly use the Camshaft position sensor wire. This is pin 18 on the C1 (Black) PCM connector. The wire is tan with a yellow tracer.

What are you looking to data log?
jeepxj3 wrote:The OBD port is CAN BUS data. I think you can data log it on Torque Pro.
It is not. Can bus wasn't used then. It is ISO 9141/CCD bus. Either way it is still called an OBD2 port.

Re: Recording sensor data through OBD2 or analog input?

Posted: October 12th, 2015, 4:39 pm
by Burnsmacdonald
Can you just splice into the CPS wire to pick up the tach feed without affecting the CPS/ECU?

Re: Recording sensor data through OBD2 or analog input?

Posted: October 12th, 2015, 5:22 pm
by SilverXJ
Just to be clear you T in to it. As long as the device you are using the wire for only receives it will be fine.

Re: Recording sensor data through OBD2 or analog input?

Posted: October 17th, 2015, 9:46 pm
by gradon
I had an lm-2 and I could get 4-5 high priority parameters to log before the lm2 would bog. I usually chose wideband, rpm, tps, short term fuel trim, and open loop notification(could be a low-priority parameter). I didn't use the programmable analog inputs.

Re: Recording sensor data through OBD2 or analog input?

Posted: October 18th, 2015, 6:04 pm
by nicpaige
Thanks for the replies!