The 1990 Engine Control Wiring Harness

Posted by 19Eclipse90, Aug 31, 2011
Articles: Electrical & Wiring -

  1. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    *****IMPORTANT*****
    Note that the wire color layout diagrams accompanying each picture are as seen FROM the CONTROL HARNESS SIDE of the connector with the release tab (for a male side connector) or locking notch (for a female side connector) on top. That is, you are looking at the wires going into the connector, OPPOSITE the side that is pictured. Like this: How to identify ECU pin numbers.
    *******************

    This is the ENGINE CONTROL harness. If you want information on the ENGINE COMPARTMENT harness, see: The 1990 Engine COMPARTMENT Wiring Harness.

    As we all know, the 1990 model year had many quirks to it when compared to the later model 1Gs. Because this was a single (and the first) year of the Eclipse/Talon/Laser trio, information on these cars isn't nearly as abundant as 1991-1994 models.

    I don't plan to dive into and explain the differences between these models as there are plenty of threads around naming the differences. In short, this article is a configuration diagram. It aims to familiarize members with the 1990 4G63 turbo engine control harness electrical connections, similar to what snowborder714 did in his 2g Engine Bay Electrical Connections article, but not nearly as thorough. To be clear, this article does not cover every electrical connection in the 1990 engine bay, only those on the engine control harness, including the handful of interior connections. For your convenience, the 1991 configuration diagrams are provided.

    1G_EL_EB_zpsoess5oq2.jpg

    1G_EL_EN_zpsrc3bziej.jpg

    1G_EL_DH_zpsdhuxsohc.jpg

    1G_EL_DH2_zps2xtgaioo.jpg

    As a couple extras, it will touch on some connector differences that must be attended to when swapping a 1990 turbo engine control harness into a later model 1G or vice versa (these are denoted by **). It lists original wire colors and original individual wire locations as viewed from the wire side of the connector as well as a visual of each connector on the harness.

    Also, for comparison, here is a similar page for the later model 1Gs (those connectors labeled with * are either completely different, in a different location, or non-existent on the later model 1Gs): 1Gb DSM 4G63 Turbo Wiring Harness Diagram

    First and foremost, the main harness itself. The alphanumeric identifiers relate to those in the 1991 configuration diagram found in the electronic copy of the factory service manual: Download the 1G Service Manuals. The harness displayed here is a 1990 turbo engine harness which, by consequence, means it is from a vehicle with a manual transmission.

    Click to enlarge slightly or zoom by pressing Control and + (the plus sign):
    90Control_Harness_Configuration_Diagram001.jpg
    To shrink, press Control and - (the minus or negative sign).

    A-08: Dual Pressure Switch (black connector, 2-pin)
    A-09: Wiper Motor (black connector, wide rectangular 4-pin)
    A-10: Control Wiring Harness and Battery Cable Assembly Combination (black connector, square 4-pin)
    *A-11: Auto-Cruise Control Actuator (black connector, square 4-pin)
    A-12: Brake Fluid Level Sensor (black connector, stacked 2-pin)
    A-13: Control Wiring Harness and Solenoid Valve Harness Assembly Combination (black connector, rectangular 6-pin)
    A-36: Air Flow Sensor (black connector, NT 6-pin, Turbo 8-pin)
    A-51: Waste Gate Solenoid (black connector, stacked 2-pin)
    A-52: Control Wiring Harness and Engine Compartment Wiring Harness Combination (black connector, wide rectangular 4-pin)
    A-53: Control Wiring Harness and Engine Compartment Wiring harness Combination (black connector, large 1-pin)
    A-55: Fuel Pump Check Connector (black connector, small 1-pin)
    A-56: Noise Condenser (black connector, very small 1-pin)
    A-57: Defogger Relay (black connector, 5-pin)
    A-58: Injector Resistor Pack (black connector, rectangular 6-pin)
    A-59: Engine Speed Adjustment Connector (black connector, small 1-pin)
    A-60: Ignition Timing Adjustment Connector (black connector, 2-pin)

    *B-00: Noise Filter (for Tachometer) (black connector, stacked 2-pin)
    B-01: Injector No. 4 (black connector, 2-pin)
    *B-02 & B-05: Throttle Position Sensor and Idle Switch (black connector, square 4-pin)
    **B-04: Idle Speed Control Actuator (black connector, rectangular 6-pin)
    B-06: Injector No. 3 (black connector, 2-pin)
    B-07: Detonation (Knock) Sensor (grey / gray connector, 2-pin)
    B-08: EGR Temperature Sensor (black connector, 2-pin)
    B-09: Injector No. 2 (black connector, 2-pin)
    B-10: Injector No. 1 (black connector, 2-pin)
    *B-14: Ignition Coil (Coil Pack) (black connector, square 4-pin)
    *B-15: Power Transistor Unit (black connector, straight 6-pin)
    B-16: A/C Magnetic Clutch (black connector, round 1-pin)
    B-26: Oxygen (O2, 02) Sensor (black connector, round 4-pin)
    B-29: Engine Coolant Temperature Gauge Unit (black connector, small 1-pin)
    B-30: Engine Coolant Temperature Sensor (for ECU) (black connector, stacked 2-pin)
    B-31: Engine Coolant Temperature Switch (for A/C) (black connector, 2-pin)
    *B-32: Crank Angle and Top Dead Center Sensor (Cam Angle Sensor, CAS) (black connector, square 4-pin)

    C-56: Oxygen (O2, 02) Sensor Check Connector (milk white connector, small 1-pin)
    C-57: Control Wiring Harness and Body Wiring Harness Combination (milk white connector, 1-pin, passenger side kick panel)
    **C-58: Control Wiring Harness and Body Wiring Harness Combination (white connector, 16-pin, passenger side kick panel)
    C-59: Control Wiring Harness and Body Wiring Harness Combination (milk white connector, 6-pin, passenger side kick panel)
    C-63: MPI Control Relay (milk white connector, 10-pin)
    C-64: MPI Control Unit (ECU, small connector) (yellow connector, 10-pin)
    C-65: MPI Control Unit (ECU, medium connector) (yellow connector, 18-pin)
    **C-66: MPI Control Unit (ECU, large connector) (yellow connector, 24-pin)
    **C-67: Control Wiring Harness and Body Wiring Harness Combination (under center console) (white connector, 8-pin)

    The wire color layout diagrams accompanying each picture are as seen FROM the HARNESS SIDE of the connector with the release tab (for a male side connector) or locking notch (for a female side connector) on top. They should be color coded correctly, but if there is a disagreement with the letters and the color of the letters, go by the letters. When two colors are listed together, the first is the main color and the second is the color of the stripe or tracer. The letters represent the following colors:

    B - Black
    W - White
    R - Red
    G - Green
    L - Blue
    Y - Yellow
    O - Orange
    Lg – Light Green

    PM me if you find any errors and I will make corrections as necessary.

    Finally, the following supporting vendors supply the individual connectors linked or partial kits for different model year DSMs:
    JNZ Tuning
    Extreme PSI
    Magnus Motorsports

    At the end of the day, they are all coming from Sheridan Engineering.
     

    Attached Files:

    Last edited: Apr 11, 2015
    #1
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  2. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    A-08: Dual Pressure Switch
     

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    Last edited: Oct 21, 2011
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  3. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    A-09: Wiper Motor

    Need a new Wiper Motor connector? See: DSD04 F.
     

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    Last edited: Feb 28, 2014
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  4. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    A-10: Control Wiring Harness and Battery Cable Assembly Combination

    Need a new Control Wiring Harness and Battery Cable Assembly Combination connector? See NMWP 4P Female.
     

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    Last edited: Feb 28, 2014
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  5. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    *A-11: Auto-Cruise Control Actuator

    One of the "mystery" connectors that seems to come up relatively frequently, 1990 models had the cruise control unit in front of the battery instead of on the firewall like the 1991+ models. It is also of note that the 1990 cruise control is mechanically actuated and does not use vacuum.

    Need a new Auto-Cruise Control Actuator connector? See NMWP 4P Female.
     

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    Last edited: Apr 11, 2015
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  6. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    A-12: Brake Fluid Level Sensor

    Need a new Brake Fluid Level harness connector? See: DSD02 F.
     

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    Last edited: Feb 28, 2014
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  7. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    A-13: Control Wiring Harness and Solenoid Valve Harness Assembly Combination

    Need a replacement connector to attach to your solenoid valve harness? See: NMWP 6P Female.

    Have this open and want to seal it up? Use this male connector to protect it from the elements! See: NMWP 6P Male.
     

    Attached Files:

    Last edited: Mar 13, 2014
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  8. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    A-36: Air Flow Sensor

    The picture below is for a turbo MAF. A non-turbo harness has only six wires (in two rows of three) running to it -- the one that will not be present is the green with white stripe which runs to pin 14 on C-66.

    Need a new 1G turbo MAF connector? See NMWP 8P female.

    Need a new 1G non-turbo MAF connector? See: NMWP 6P Female.

    Interested in upgrading to a 2G MAF and don't have the connector? See: CON-2GMAF-8F.

     

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    Last edited: Apr 11, 2015
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  9. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    A-51: Waste Gate Solenoid

    1G ECU Pinouts

    ERROR: Note that the "yellow" wire is actually ORANGE and runs to pin 105 of the ECU.


    Need a new Brake Fluid Level Sensor harness connector? See: DSD02 F.
     

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    Last edited: Feb 28, 2014
    #9
  10. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    A-52: Control Wiring Harness and Engine Compartment Wiring Harness Combination

    Need a new harness combination connector? See: DSD04 F.

    This is one of the connectors that joins the Engine CONTROL Wiring Harness with the Engine COMPARTMENT Wiring Harness. Specifically, it joins with this connection: The 1990 Engine COMPARTMENT Wiring Harness.

    NOTE: This is one of the connections UNDERNEATH the fuse box; there are no connections running to the fuse box itself.
     

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    Last edited: Jun 21, 2014
    #10
  11. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    A-53: Control Wiring Harness and Engine Compartment Wiring harness Combination

    This is one of the connections that join this harness and the engine control harness together. Specifically, it joins with this connection on the Engine Control Wiring Harness: The 1990 Engine COMPARTMENT Wiring Harness.

    NOTE: This is one of the connections UNDERNEATH the fuse box; there are no connections running to the fuse box itself.

    This connector can be had new here: 1G 312 F
     

    Attached Files:

    Last edited: Apr 10, 2015
    #11
  12. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    A-55: Fuel Pump Check Connector

    Just a short note of interest for you folks with a 1991 engine harness: 1g base timeing/confusing.

    Need a new Fuel Pump Check connector? See: DSD01 F.
     

    Attached Files:

    Last edited: Jun 21, 2014
    #12
  13. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    A-56: Noise Condenser
     

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    Last edited: Oct 21, 2011
    #13
  14. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    A-57: Defogger Relay
     

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    Last edited: Oct 21, 2011
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  15. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    A-58: Injector Resistor Pack

    Note that this is a turbo car item only. Make sure not to confuse it with B-04: Idle Speed Control Actuator.
    Need a new Injector Resistor Pack harness connector? See: NMWP 6P Female.

    Need the mating connector for the injector restistor pack? See: NMWP 6P Male.
     

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    Last edited: Jan 25, 2015
    #15
  16. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    A-59: Engine Speed Adjustment Connector

    Need a new Engine Speed Adjustment connector? See: DSD01 F.
     

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    Last edited: Feb 28, 2014
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  17. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    A-60: Ignition Timing Adjustment Connector

    Need a new Ignition Timing Adjustment cover to seal this terminal up? See: NMWP 2P B Female.

    Need a new Ignition Timing Adjustment harness connector? See: NMWP 2P Male.
     

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    Last edited: Mar 2, 2014
    #17
  18. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    B-00: Noise Filter (for Tachometer)

    For good measure, you can check this link to see what, exactly, connects here. If the NOISE FILTER is missing, your 1990 tachometer will not work: Rpm Gauge

    Note that the 1990 tachometer receives its signal from the tachometer gate interface module that is attached to the coil pack. The signal is output to the white wire at pin 3. This is the tacho interface: Stock tach doesnt work, but tach works on SAFC

    Also for reference:
    Lil Evo Tachometer Fix
    help with tach

    The OEM part number for the noise filter is MB542494. Whether or not you can find them new again is completely up to you.

    Fortunately, there are ways to get around having the filter. Check this useful article out for details: How To: Fix a 1990 DSM tach..

    TIP: After numerous trips to the junkyard, I've collected a small (5) supply of these noise filters. They all work as I have tried them on my own vehicle. The kicker is that they are not all from 1990 model 1Gs. A couple of them were pulled from late 80's/early 90's model Colts. These filters are mounted by one M6 (that's a 10mm head) bolt. They have the same shape connector on them as the 1990 unit. Something else I found is that, in order for the noise filter to work correctly, the filter (or mounting bracket, as is the case for the Colt style filter) must be grounded to the intake manifold. If this is not done, the tachometer will jump around and tends to get stuck around 3000rpm. The Colt part number is MB627900 or MB627901, depending on options; either should work. Having said that, I wouldn't expect them to be any cheaper new than the 1G units.

    Need a new Noise Filter harness connector? See: DSD02 F.
     

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    Last edited: Jun 21, 2014
    #18
  19. 19Eclipse90

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    B-01: Injector No. 4

    Looking for a new injector connector? See JFC 2P.
     

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    Last edited: Feb 28, 2014
    #19
  20. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    B-02 & B-05: Throttle Position Sensor and Idle Switch

    The 1990 model integrated the idle switch into the throttle position sensor connector. When using a 1991+ throttle body, the green wire in the dotted box would need to run to the idle switch. For a write up on this site: 1990 Swap to 91-94 Throttle Body

    Need a new 1990 harness side TPS connector? See NMWP 4P Male.

    Need a new 1990 sensor side TPS connector? See NMWP 4P Female.

    Have a 1991+ TPS? See JFC 4PB .
     

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    Last edited: Jun 21, 2014
    #20
  21. 19Eclipse90

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    **B-04: Idle Speed Control Actuator

    Make sure not to confuse this with A-58: Injector Resistor Pack on a turbo vehicle. Do not confuse this with A-58: Injector Resistor Pack.
    ERROR: The wire colors orientation shown here is as found in '91+ vehicles. In a '90 vehicle, the white and black wire are swapped; pin 4 is the white and pin 6 is the black. See this post and the one following it: 91 iac in 90, looking for the ecu pinouts between 90/91.

    Need a new ISC actuator motor harness connector? See: NMWP 6P Female.

    Need the mating connector for the ISC actuator motor? See: NMWP 6P Male.
     

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    Last edited: Jun 21, 2014
    #21
  22. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    B-06: Injector No. 3

    Looking for a new injector connector? See 18. - JFC 2P.
     

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    Last edited: Feb 28, 2014
    #22
  23. 19Eclipse90

    19Eclipse90 DSM Wiseman

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    B-07: Detonation (Knock) Sensor

    Note the color ( gray ) of this connector / connection / plug; it is the same for all turbo DSMs and is the only connector of this color in the 1G engine compartment.

    Need a new knock sensor connector? See NMWP 2P GY female.
     

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    Last edited: Feb 28, 2014
    #23
  24. 19Eclipse90

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    B-08: EGR Temperature Sensor

    Need a new EGR Temp Sensor Connector? See: NMWP 2P B Female.
     

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    Last edited: Feb 28, 2014
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  25. 19Eclipse90

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    B-09: Injector No. 2

    Looking for a new injector connector? See JFC 2P.
     

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    Last edited: Feb 28, 2014
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