K20z3 Ecu Pinout Jun 2026

| Pin | Wire Color | Function | Notes | |-----|------------|----------|-------| | C1 | Wht/Red | APP Sensor 1 (Accel Pedal Position) | Signal | | C2 | Red | APP Sensor 2 | Redundant signal | | C3 | Brn | APP Sensor 1 Ground | | | C4 | Grn | APP Sensor 2 Ground | | | C5 | Blu/Red | APP Sensor 1 +5V Ref | | | C6 | Yel/Wht | APP Sensor 2 +5V Ref | | | C7 | Pur | Primary O2 Sensor (Air/Fuel Ratio – wideband) | LAF sensor | | C8 | Grn/Red | Primary O2 Heater Control | Ground-side switching | | C9 | Blu | Secondary O2 Sensor (post-cat) | Narrowband | | C10 | Red/Blk | Secondary O2 Heater Control | | | C11 | Wht/Blk | MIL (Malfunction Indicator Lamp – Check Engine) | Ground output | | C12 | Grn/Yel | Tachometer Output | Signal to cluster | | C13 | Wht/Blu | CAN-High (OBD-II communication) | | | C14 | Yel/Blu | CAN-Low | | | C15 | Pur | K-Line (ISO 9141-2) – older diagnostics | | | C16 | Grn | A/C Pressure Switch Input | | | C17 | Red | Clutch Pedal Position Switch (starter interlock) | | | C18 | Blu/Yel | Immobilizer Control Unit (communication) | | | C19-C48 | – | Various: VSA, EPS, ABS, cruise control, cooling fan high speed, A/C request, etc. | Highly model-specific |

Disclaimer: This report is for informational purposes only. Always use manufacturer-approved documentation for actual wiring modifications. Incorrect wiring can damage the ECU or engine.

However, whether you are swapping this engine into a classic EG/EK Civic, building a standalone management system, or simply chasing a wiring gremlin in your stock Si, you will eventually hit a wall: k20z3 ecu pinout

Unlike its predecessor (PRB ECU from the DC5), the K20Z3’s ECU introduced:

If you are reading this for a standalone build: | Pin | Wire Color | Function |

Always verify pin colors before cutting. While pin locations remain consistent, wire colors can occasionally vary by production year. Use a digital multimeter to check for continuity to ground on any "SG" (Sensor Ground) pins to ensure your harness is healthy.

| Pin | Wire Color | Function | Notes | | :--- | :--- | :--- | :--- | | D1 | Pink | IMMO (Immobilizer Code Line) | Communication to Immobilizer box | | D2 | Blue/Red | IMMO Power | 12V for immobilizer receiver ring | | D3 | Yellow/Black | F-CAN High (Body CAN bus) | For cluster, ABS, EPS | | D4 | White/Black | F-CAN Low | Complementary CAN line | | D5 | Red | SCS (Service Check) | Alternative to A27 | | D6 | Green | K-Line (2nd diag) | | | D7 | Black | PG (Ground) | Digital ground | | D8-D16 | Various | Not used (or audio/navigation inputs) | | Incorrect wiring can damage the ECU or engine

RPM and Vehicle Speed Signal (VSS) are typically found on the A connector for aftermarket devices.

| Pin | Wire Color | Function | Notes | | :--- | :--- | :--- | :--- | | C1 | Red/Blue | VTC Oil Control Valve (+) | Solenoid for cam advance | | C2 | White/Black | VTC Oil Control Valve (-) | Ground side | | C3 | Yellow | ACC (Throttle Actuator +) | Controls throttle plate open | | C4 | Blue | ACC (Throttle Actuator -) | Controls throttle plate close | | C5 | Green | TPS Sub (Throttle Position Sensor 2) | Secondary TPS (0.5V WOT, 4.5V idle) | | C6 | Red | TPS Main (Throttle Position Sensor 1) | Primary TPS (4.5V WOT, 0.5V idle) | | C7 | Red/Black | APP Sensor (Accel Pedal Position) | Pedal sensor – different from TPS | | C8 | Gray | A/C Compressor Clutch Relay | Ground to engage A/C | | C9 | Light Green | A/C Pressure Switch | Input from A/C system | | C10 | Yellow/Green | Cooling Fan Relay (Low) | Controls low speed fan | | C11 | Blue/Black | Cooling Fan Relay (High) | Controls high speed fan | | C12 | White/Black | Alternator C (Control) | Charging system control | | C13 | Red/White | Alternator IG (Ignition) | Alternator exciter | | C14 | White | EVAP Canister Purge Valve | Emissions control | | C15 | Brown | EVAP Bypass Solenoid | | | C16-C22 | Various | Empty or chassis-specific signals | (MIL control for emissions, etc.) |

For those integrating a K20Z3 into another chassis, the CR-Z Forum provides a comprehensive build guide with complete wiring diagrams.

If you need to add wires for features like VTEC or sensors, follow this guide for depinning Honda connectors from YouTube .