Engine Harness Colors and meaning
#1
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Engine Harness Colors and meaning
I'm working on integrating my factor 2001 Harness pig tails to a Fuel Tech FT450. I can't find any place where it tell me what wire does what. This weekend I will fill in the empty wire colors.
Last edited by 1993ka24det; 06-23-2023 at 03:45 PM.
#2
Wiring diagram for '01 is pretty easy to find.
https://www.mellens.net/mazda/mazda_...001_wiring.pdf
Cam Sensor:
Black/Blue: Ground
Gray/Blue : Sensor Signal (Pin 3V of ECU)
W/R : 12v
Injectors
White/Blue - 12v
Other Colors - Signal from ECU
Air Temp
Piink/Blue - 4N of ECU Connector
Black/Red = Sensor Ground 4O of ECU connector
The rest should be pretty easy to identify. Most should be in one of the three "Engine Performance Circuits" pages.
https://www.mellens.net/mazda/mazda_...001_wiring.pdf
Cam Sensor:
Black/Blue: Ground
Gray/Blue : Sensor Signal (Pin 3V of ECU)
W/R : 12v
Injectors
White/Blue - 12v
Other Colors - Signal from ECU
Air Temp
Piink/Blue - 4N of ECU Connector
Black/Red = Sensor Ground 4O of ECU connector
The rest should be pretty easy to identify. Most should be in one of the three "Engine Performance Circuits" pages.
#3
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Join Date: Oct 2011
Location: The Race Track & St Pete FL
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Wiring diagram for '01 is pretty easy to find.
https://www.mellens.net/mazda/mazda_...001_wiring.pdf
Cam Sensor:
Black/Blue: Ground
Gray/Blue : Sensor Signal (Pin 3V of ECU)
W/R : 12v
Injectors
White/Blue - 12v
Other Colors - Signal from ECU
Air Temp
Piink/Blue - 4N of ECU Connector
Black/Red = Sensor Ground 4O of ECU connector
The rest should be pretty easy to identify. Most should be in one of the three "Engine Performance Circuits" pages.
https://www.mellens.net/mazda/mazda_...001_wiring.pdf
Cam Sensor:
Black/Blue: Ground
Gray/Blue : Sensor Signal (Pin 3V of ECU)
W/R : 12v
Injectors
White/Blue - 12v
Other Colors - Signal from ECU
Air Temp
Piink/Blue - 4N of ECU Connector
Black/Red = Sensor Ground 4O of ECU connector
The rest should be pretty easy to identify. Most should be in one of the three "Engine Performance Circuits" pages.
This is the Wire system for the Fuel Tech 450, it's pretty simple then looking at the 3 pages for the Miata Engine Harness
#4
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There is also 3 connectors on the front of the Engine. The First 1 on the Left is for the Injectors, but there are 3 wires that don't make sense for what they would correlate with the wiring diagram mentioned above. What is the Center connector for, ground maybe. I don't see it in the Diagram.
Here is 1st of the 3, all 8 wires
Then the 3 left over wire?
The second connector has 4 wires, all mosty black
#1 Blk
#2 Blk/Wht
#3 Blk
#4 Blk/Wht
Here is 1st of the 3, all 8 wires
Then the 3 left over wire?
The second connector has 4 wires, all mosty black
#1 Blk
#2 Blk/Wht
#3 Blk
#4 Blk/Wht
#5
Trace the wire all the way back to the PCM in the diagram
You see how for all the blk/red (for IAT, CLT Temp, TPS, etc) goes back to pin 4O of the ecu connector?
Take that information and then look at the ecu pinout
https://www.miataturbo.net/attachmen...cu_pinouts.pdf
Reviewing the ECU Pinout PDF, we see that 4O = Sensor ground.
---
Note, most tempature sensors are only 2 pins which are "Signal Ground" and "Sensor Output". There is no 5v which is why you see the IAT sensor only have 2 plugs and none of them being 5v.
---
If you want to see which wire is 5v, it is 4L on the ECU connector (confirm this on the ECU Pinout PDF).
This would be the Light Green/Red wire you see on the TPS.
---
In my opinion, your best bet is to NOT touch any wires in the engine bay. Buy/build a jumper harness like this (facebook[.]com/groups/MiataDIY/permalink/3521791234814711/) and then wire your fueltech directly to the ecu connector.
You see how for all the blk/red (for IAT, CLT Temp, TPS, etc) goes back to pin 4O of the ecu connector?
Take that information and then look at the ecu pinout
https://www.miataturbo.net/attachmen...cu_pinouts.pdf
Reviewing the ECU Pinout PDF, we see that 4O = Sensor ground.
---
Note, most tempature sensors are only 2 pins which are "Signal Ground" and "Sensor Output". There is no 5v which is why you see the IAT sensor only have 2 plugs and none of them being 5v.
---
If you want to see which wire is 5v, it is 4L on the ECU connector (confirm this on the ECU Pinout PDF).
This would be the Light Green/Red wire you see on the TPS.
---
In my opinion, your best bet is to NOT touch any wires in the engine bay. Buy/build a jumper harness like this (facebook[.]com/groups/MiataDIY/permalink/3521791234814711/) and then wire your fueltech directly to the ecu connector.
#6
Senior Member
Thread Starter
Join Date: Oct 2011
Location: The Race Track & St Pete FL
Posts: 638
Total Cats: 57
Trace the wire all the way back to the PCM in the diagram
You see how for all the blk/red (for IAT, CLT Temp, TPS, etc) goes back to pin 4O of the ecu connector?
Take that information and then look at the ecu pinout
https://www.miataturbo.net/attachmen...cu_pinouts.pdf
Reviewing the ECU Pinout PDF, we see that 4O = Sensor ground.
---
Note, most tempature sensors are only 2 pins which are "Signal Ground" and "Sensor Output". There is no 5v which is why you see the IAT sensor only have 2 plugs and none of them being 5v.
---
If you want to see which wire is 5v, it is 4L on the ECU connector (confirm this on the ECU Pinout PDF).
This would be the Light Green/Red wire you see on the TPS.
---
In my opinion, your best bet is to NOT touch any wires in the engine bay. Buy/build a jumper harness like this (facebook[.]com/groups/MiataDIY/permalink/3521791234814711/) and then wire your fueltech directly to the ecu connector.
You see how for all the blk/red (for IAT, CLT Temp, TPS, etc) goes back to pin 4O of the ecu connector?
Take that information and then look at the ecu pinout
https://www.miataturbo.net/attachmen...cu_pinouts.pdf
Reviewing the ECU Pinout PDF, we see that 4O = Sensor ground.
---
Note, most tempature sensors are only 2 pins which are "Signal Ground" and "Sensor Output". There is no 5v which is why you see the IAT sensor only have 2 plugs and none of them being 5v.
---
If you want to see which wire is 5v, it is 4L on the ECU connector (confirm this on the ECU Pinout PDF).
This would be the Light Green/Red wire you see on the TPS.
---
In my opinion, your best bet is to NOT touch any wires in the engine bay. Buy/build a jumper harness like this (facebook[.]com/groups/MiataDIY/permalink/3521791234814711/) and then wire your fueltech directly to the ecu connector.
I don't have Facebook anymore and they require to log on to view.
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