I have an OTC nemisys scanner. When I hook it up to check codes or do some data logging, the idle kicks up a bit. Some of the things I want to check and monitor, I want to check while at idle. Not while the idle is kicked up. When I get into data logging on the scanner, I can choose from 3 different modes which each does different things. IIRC, the modes are ALDL, fuel back-up and service mode. Which mode should I use if I want to check stuff at idle, and what mode should I use if I want to check stuff while driving? I've read that using the wrong mode for what you want to do can harm the things. Thanks.

 

Open mode is required... I'm not sure which mode to use from your list. To not change how the ECMs runs, pin B on the ALDL connector needs to be open.

To further confuse the matter, which baud (data) rate to run the ALDL port depends upon a 10K resistor. From pin B to ground (pin A).

Without using the 10K resistor the ECM will communicate at 160 baud.

To communicate at 8192 baud, need to place the 10K resistor between ALDL pins A & B. Once a link is established the resistor should be removed.

RBob.