Proton Wira Wiring Diagram May 2026

The Proton Wira power window circuit is notorious for slow movement and failure, especially on the driver’s side.

Enthusiasts love swapping the 4G15 to a 4G93 DOHC or adding MIVEC. The wiring diagram is your roadmap.

  • Aftermarket ECU (Standalone): Use the diagram to identify the stock Crank Angle Sensor (CAS) wires (Yellow and Red) and ignition output wires. You don't cut the whole harness; you intercept the diagram's signals.
  • Here are the five critical sections of the Wira harness you must master.

    Proton follows Mitsubishi’s color code system. The first letter = base color, second = stripe. proton wira wiring diagram

    | Abbr. | Color | Function | | :--- | :--- | :--- | | B | Black | Primary ground (chassis/body) | | B/Y | Black/Yellow | Ignition-switched ground (ECU) or main ground | | R | Red | Constant battery +12V (unfused/fused) | | B/R | Black/Red | Main relay control or sensor ground | | W | White | Alternator charge output | | W/B | White/Black | Ignition coil negative (tachometer signal) | | Y | Yellow | Starter solenoid signal | | G | Green | Sensor signals (TPS, MAP, water temp) | | L | Blue | Accessory/switched +12V (heater, wipers) | | O | Orange | Lighting (parking, tail, dash illumination) |

    Critical: A wire labeled B/Y is not positive. It is almost always a switched ground or chassis ground.

    The Wira has a dedicated door sub-harness that often breaks in the rubber boot between chassis and door. The Proton Wira power window circuit is notorious

    Power window logic (Driver door master switch):

    Central locking (If equipped):


    Proton Wira headlights run on a negative switching system (the relay coil is grounded by the steering column stalk). Aftermarket ECU (Standalone): Use the diagram to identify

    Troubleshooting: If the fuel pump doesn’t prime, check the Engine Control Relay (behind the radio/dashboard). The ECU grounds pin 12 (Black/Green) to turn it on.

    Let's say your Proton Wira fuel pump is not priming. Here is how you use the diagram:

  • No diagram? You would be swapping pumps, relays, and ECUs blindly.