2003 Miata Main Relay ground
#1
SADFab Destructive Testing Engineer
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2003 Miata Main Relay ground
Diagnosing a MSPNPPro (MM01-05). The main relay isn't turning on.
Looking at the 2003 diagram it looks like the ECU is supposed to ground out the relay and turn it on. Yet in Franks MS3 guides, and on this ECU, pin 3H (the one connected to the main relay) does nothing.
Car works fine if you ground out the main relay manually.
Is there some undocumented feature of the stock ECU that triggers the main relay?
Looking at the 2003 diagram it looks like the ECU is supposed to ground out the relay and turn it on. Yet in Franks MS3 guides, and on this ECU, pin 3H (the one connected to the main relay) does nothing.
Car works fine if you ground out the main relay manually.
Is there some undocumented feature of the stock ECU that triggers the main relay?
#3
SADFab Destructive Testing Engineer
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iTrader: (5)
Join Date: Apr 2014
Location: Beaverton, USA
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Also, is this documented anywhere? Or did you guys just figure it out when making one?
I'm surprised Frank's pinout doesn't have anything related to it.
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