Help on GM ecu mode 2 and 4. EPROM dump and message sending

fastline · Post by **fastline** » Mon Aug 17, 2009 9:49 am

I am working with A GM ECU through Tunerpro. I have established communications with mode 1 for diagnostic chit chat. I would like to execute an EPROM dump with mode 2. Wondering if anyone has done this with Tunerpro?

Also, I know the ECU I am working with (diesel) supports mode 4 type functions where someone can reset the initial timing. I am not sure yet how to do this as there is not much info online about it. Does anyone know what I am referring to and how execute it?

Six_Shooter · Post by **Six_Shooter** » Mon Aug 17, 2009 10:02 am

Why not just do it the easy way and ead the prom through a programmer?

fastline · Post by **fastline** » Mon Aug 17, 2009 10:15 am

for one, I am just trying to learn the process but also because mode 4 is rather important for timing setups. This is also true for OBDII vortecs that require a tech 2 to set the timing up. Need to learn how to chat with the ECU and do small tasks.

I also do not have a burner just yet and wanted to ensure that we have all we need before doing that. Guess itwill make me feel better if I dump the EPROM from the diag port and get the same thing as what I get from my burner setup.

Six_Shooter · Post by **Six_Shooter** » Mon Aug 17, 2009 12:31 pm

Why do you need to use mode 4 for timing set-up?

I've never used mode 4, just open the ESC wire, and the module goes to base timing.

I think you're making this way more difficult on yourself than it really needs to be.

fastline · Post by **fastline** » Mon Aug 17, 2009 1:11 pm

NO ESC wire on a diesel.

Six_Shooter · Post by **Six_Shooter** » Mon Aug 17, 2009 3:25 pm

I guess that would be true......

I missed that in the first post.