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anyone know what this yellow thing is? , It's connected to the the transmission control module. It's not in the wiring diagrams that I can see and it's not on any other harness for sale online.
are there 2 wires in that bundle? It could be a temperature sensor? Where is it plugged into on the transmission? Looks like previous owner cut whatever was there and closed it off with some tape
are there 2 wires in that bundle? It could be a temperature sensor? Where is it plugged into on the transmission? Looks like previous owner cut whatever was there and closed it off with some tape
There's 3 wires, grey, white and black, grey and white, someone has wired to the harness. I'll cut it open in a few minutes I can tell you what color wires they tapped into and maybe that will give some clues.
The Black wire from the yellow thing is connected to the chassis as a ground. Grey and white go directly into the harness.
Someone has cut the black with with red stripes , one end goes to the white wire and the grey is attached to the plug side. 🤔🤷♂️ It seems to be some sort of bypass or something.
I wonder if at one time it was encased in a small plastic box and bolted under the dash. It's odd thats fore sure but I'm not sure if its aftermarket. I'd be curious to look through the wiring diagrams.
That thing sure doesn't look Mazda OEM to me - I'd guess it's an aftermarket piece or something a previous owner built. Obviously there's a small circuit board with a few components sealed up under that yellow potting goo material or heat shrink cover.
No clue on what it's purpose is at this point. If I were the OP, I'd trace the wires back to where they connect to the OEM harness and ID all the wire colors and connection points. Armed with that info, we might be able to consult the FSM wiring diagrams and possibly reverse-engineer what the little mystery circuit could be doing.
Since it's apparently wired into the AT's TCM, is there anything odd about the way the automatic transmission shifts or otherwise behaves?
The black wire with red stripe goes into a connector then becomes the Green wire with pink stripe. It goes into the bottom row, third pin connector from the left when staring at the holes. When plugged into the ECU, it's the second plug from the left as pictured.
The black wire with red stripe goes into a connector then becomes the Green wire with pink stripe. It goes into the bottom row, third pin connector from the left when staring at the holes. When plugged into the ECU, it's the second plug from the left as pictured.
Now we maybe getting somewhere... The ECU connector you're holding in the picture is the EM-31 connector from the emissions harness, and the Black/Red stripe wire (3rd pin, bottom row, pin # 3V per the FSM wiring diagram, page Z-27) should be going straight to one of the coils in the Oil Metering Pump (OMP) stepper motor on the engine. There should be NOTHING ELSE connected to or spliced into that wire for a stock OEM installation.
Now we maybe getting somewhere... The ECU connector you're holding in the picture is the EM-31 connector from the emissions harness, and the Black/Red stripe wire (3rd pin, bottom row, pin # 3V per the FSM wiring diagram, page Z-27) should be going straight to one of the coils in the Oil Metering Pump (OMP) stepper motor on the engine. There should be NOTHING ELSE connected to or spliced into that wire for a stock OEM installation.
I was wrong. I tried to be lazy. It was 110 degrees today and I was dying under the dash with sticky fingers from unwrapping old electrical tape. It's the First plug from the left on the ECU. Green wire Pink stripe ( that's what got me confused, two wires are the same color in the same harness. )
I don't know what it could be. I have a few guesses.
i looked into TCM bypass and theres a few forums of people who rig some lightbulb components in and it imitates a relay.
For some reason I also think maybe they ended up in some safety mode on the transmission, I read there's safety features to ensure the transmission doesn't harm itself, I think maybe it could have possibly went into limp mode and they tried to find ways to get around it?
The car had a fried ECU. I just replaced the ECU and I'm trying to get the wiring all correct before powering it all up ( for the guy who asked if it's shifting weird)
I'm not sure what it is from what I can see. It looks like more than a simple relay.
It kinda reminds me of the parking brake simulator a lot of people use when they install aftermarket radios, but much larger. I'd guess it is some sort of timer based circuit. ie it provides a pulsed signal, or perhaps a delayed signal to the ecu.
I don't know enough about FCs to really make an educated guess though. If you do end up keeping it, those twisty wire splicers aren't really good to use in a car though.
08-10-20, 01:02 PM
