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Cart before the horse?


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OK, unless I've got this very wrong it seems that the ECU hold power option is akin to putting the cart before the horse. If the harness is wired up for ECU hold then the ECU will not turn on. You have to first power up the ECU, update and program independently of the harness if the harness has been setup for ECU hold. After pulling my hair out for a couple hrs going over pin-outs and wiring I took the ECU to the bench and ran it there with power/ground only on the 'A' plug and connected to the PC. Turned on and communicated just fine, a bit more digging and realized that the ECU hold option has to be turned on to work, there is no "sense" for this configuration (this is a thunder unit). But as noted if the harness is setup for ECU hold it will not turn on, so it has to bench tested and run first. That should be noted somewhere.

Anyone else run into this? 

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Yes, I even had an in ignition signal to hopefully trigger it to power up. No blue light and no PC connection. On the bench with +12v only to plug 'A' and ground, blue light and PC link. 

The diagram I have shows the Main +- & ign switch on Plug 'C'. Plug 'D' is wired for power though. 

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Hi Mondi8, thanks for letting us know about the problem.

I've just taken a look at the Thunder base-map as it is when we ship it. This has the Ignition Switch 'On Level' set to High, and the Main Relay Driver 'Function' set to ECU Hold Power. Is this how your settings were when you powered the ECU up on the bench? I would have thought with the settings set like this the ECU would power up when the Ignition switch input received +12V to its pin. This is assuming the ECU Hold power wiring is complete.

I don't have a Thunder ECU here at the moment, but I'll check back here to see what your settings were, and then try and get hold of a Thunder to test this on. We can then change the default Thunder settings if required so this is not a problem for other users.


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