Description

Mitsubishi 4G63, 4G64 Wiring Diagram – Factory Specs for MPI and GDI

Get stuck tracing a no-start on a 4G63 because some third-party diagram crossed two pins? I’ve seen it happen. You spend hours chasing a ghost ground, then find out the aftermarket print had the wrong sensor connector layout. This 138-page Mitsubishi 4G63, 4G64 Wiring Diagram manual comes straight from the factory – no reprints, no redrawn guesswork. It opens with the ignition system for both MPI and GDI engines, then walks you through every circuit the engineers put on paper. If you’re pulling a harness apart or adding an aftermarket ECU, this is the reference you keep on the bench.

Ignition System: MPI and GDI Variants

Turn to page 4-2 and you get the full ignition circuit for the MPI setup – crank angle sensor, camshaft position sensor, ignition coils, and the ECU control outputs. The GDI ignition diagram starts on page 4-4. Both show wire colors, connector pin numbers, and the exact routing through the engine fuse box. Note the separate immobilizer system for GDI engines on page 4-136 – if you bypass it without the right diagram, the starter relay stays dead. This section pays for itself the first time you diagnose a misfire that isn’t a coil.

Engine Control System – 4G63-MPI and 4G64-GDI

Four separate full-page schematics cover the engine control unit: 4G63-MPI with manual transmission (page 4-8), 4G63-MPI with automatic (page 4-16), 4G64-GDI manual (page 4-24), and 4G64-GDI automatic (page 4-40). Each includes the oxygen sensor circuit, idle control solenoid, fuel cut relay, and the inspection output pins you need for a breakout box. No generic “engine control” diagram that tries to fit both – these are specific to each combination. If you’re swapping a 4G63 into a different chassis, the pinout data here saves you from frying an ECU.

Cooling System and INVECS-II 4A/T Circuits

Cooling system wiring on page 4-56 shows the fan relays, temperature switch, and engine temperature sensor connections. Right below it starts the 4-speed INVECS-II automatic transmission diagram (page 4-58). That section includes the shift solenoid circuit, torque converter clutch control, and the transmission range switch. If your 4G64-GDI automatic won’t shift out of limp mode, this is where you verify the solenoid resistances and power supply. The manual doesn’t guess – it lists the exact connector views from the factory.

Meter and Gauge – Left and Right Hand Drive

Wiring up a cluster from a salvage yard? The meter and gauge section splits by transmission type and steering side: manual transmission left-hand drive (page 4-70), manual right-hand (page 4-72), automatic left-hand (page 4-74), automatic right-hand (page 4-76). Each diagram shows the multi-display, warning lamps, and the brake warning lamp circuit (pages 4-78 and 4-79). The air conditioner wiring covers left and right drive separately (pages 4-80 and 4-84). If you’re retrofitting a different A/C compressor, the compressor relay and condenser fan wiring are laid out pin by pin.

Does This Manual Cover the INVECS-II Transmission?

Yes – the 4-speed automatic transmission wiring is all there on pages 4-58 through 4-68. It includes the shift lock solenoid, pulse generators, and the transmission control module connections. If you’re diagnosing an intermittent No. 3 shift issue, you’ll find the solenoid resistance specs referenced in the schematic. The diagram also shows the wiring for the 4G64-GDI engine management integration, so the ECU and TCM communicate correctly.

3 Reasons Factory Wiring Diagrams Beat Aftermarket

First, wire colors match the actual harness – no “color may vary” disclaimers. Second, pin numbers correspond to the connector face views from the Mitsubishi service manual. Third, the PDF is a direct scan of the original circuit diagram pages, not a redrawn version that loses clarity. Aftermarket diagrams often merge left- and right-hand drive into one confusing layout; this manual keeps them separate. For the Automotive Wiring basics, you can supplement with general theory, but when you need the exact path from the ignition switch to the starter relay, this is the source.

Get the Wiring Right for Cruise Control and Immobilizer

The auto-cruise control system diagrams for the 4G64-GDI with manual transmission (page 4-120) and automatic (page 4-128) show the actuator motor, control switch, and ECU inputs. The immobilizer section (page 4-136) covers the GDI engines only – it includes the transponder key coil, immobilizer ECU, and the starter inhibit relay. If you’re retrofitting cruise into a base model, these pages give you the factory splices and wire colors. Skip the aftermarket wire-tap kits; follow the OEM schematic and use the correct gauge wire.

Audience Fit: Who Needs This Manual

Home garage mechanics tackling a 4G63 swap into a DSM or a 4G64 rebuild on a Mitsubishi pickup will find the engine control and charging system diagrams essential. Professional technicians diagnosing electrical gremlins on older Mitsubishi models – Galant, Eclipse, Montero – will save diag time with the separate left- and right-hand drive sections. The manual assumes you can read a schematic and know how to use a multimeter. If you’re new to wiring, pair it with a general Automotive Wiring reference. But for pin-specific data, this 138-page factory document is your only reliable source.

Related manuals you may also need:

• Mitsubishi Rear Axle Service Manual
• Mitsubishi 4G63 Engine Service Manual
• Mitsubishi 4G64 Service Manual – OEM Factory Specs for 2.4L Engine

Does this wiring diagram include torque specs?

No. Wiring diagrams don’t list bolt torque values. Those are in the engine service manual.

Can I use this manual to diagnose a no-crank condition on a 1997 Mitsubishi Eclipse with 4G63?

Yes – the 4G63-MPI engine control diagram (page 4-8 for manual, page 4-16 for automatic) shows the starter system wiring, ignition switch circuit, and immobilizer bypass path. Check the ignition switch signal at pin B-89 (see page 4-2 for connector location). If the starter relay isn’t getting power, trace the IG1 wire back through the fuse box using the charging system diagram on page 4-6. The manual doesn’t list vehicle model years, but the engine system wiring stayed consistent through the late 90s and early 2000s for these powertrains. Verify your specific harness connector shapes – the pin positions are accurate, but Mitsubishi sometimes changed connector bodies without changing circuit numbers.

Stop hoping an aftermarket schematic got it right. Access the Factory Manual and put the correct wire color in your hands. Every circuit, every connector, every pin – straight from Mitsubishi’s electrical engineering department.