ECU Connectors and Pins

ECU Connectors & Pins

ECU connector wires are normally referred by the connector and pin. eg C27 refers to pin 27 of connector ‘C’.

Important ECU Pins

Model	Pin	Description	Use	Notes
2006-2011	A23	ELD – Electrical load input	Wideband input	ELD must be disabled & factory pin must be removed from the ECU connector.
Civic Si / Civic Type R	A33	ECT2 – Coolant temperature sensor #2	Wideband input	ECT2 must be disabled & factory pin must be removed from the ECU connector.
	B2	EGR – EGR output	Boost Control output	Normally unused.
	B29	EGRL – EGR lift input	Wideband input	Normally unused.
	C27	SO2 – Secondary O2 sensor input	–	Secondary O2 sensor must be disabled & factory pin must be removed from the ECU connector.

2012 Civic Si / ILX	A34	ELD – Electrical load input	Wideband input	ELD must be disabled & factory pin must be removed from the ECU connector.
	A44	ECT2 – Coolant temperature sensor #2	Wideband input	ECT2 must be disabled & factory pin must be removed from the ECU connector.

S2000	B16	Boost Control output (EGR)	Boost Control output	Normally unused.
	B12	Wideband input (EGRL)	Wideband input	Normally unused. See S2000 EGRL Input
	E1	ECT2 – Coolant temperature sensor #2	Wideband input	ECT2 must be disabled & factory pin must be removed from the ECU connector.
	E15	ELD – Electrical load input	Wideband input	ELD must be disabled & factory pin must be removed from the ECU connector.

2007-2008	B16	Boost Control output (EGR)	Boost Control output	Normally unused.
TSX	B12	Wideband input (EGRL)	Wideband input	Normally unused.
	B22	Wideband input	Wideband input	Normally unused.
	E1	ECT2 – Coolant temperature sensor #2	Wideband input	ECT2 must be disabled & factory pin must be removed from the ECU connector.
	E15	ELD – Electrical load input	Wideband input	ELD must be disabled & factory pin must be removed from the ECU connector.

2009-2014	A24	ELD – Electrical load input	Wideband input	ELD must be disabled & factory pin must be removed from the ECU connector.
TSX

2014-2015 Civic R18 CVT	A34	ELD – Electrical load input	Wideband input	ELD must be disabled & factory pin must be removed from the ECU connector.
	A46	ECT2 – Coolant temperature sensor 2	Wideband input	ECT2 must be disabled & factory pin must be removed from the ECU connector.
2012-2015 Civic R18 AT/MT	A34	ELD – Electrical load input	Wideband input	ELD must be disabled & factory pin must be removed from the ECU connector.
	A44	ECT2 – Coolant temperature sensor 2	Wideband input	ECT2 must be disabled & factory pin must be removed from the ECU connector.

Civic Connectors

The ECU connectors are color coded:

connectors

•	A Connector – White

•	B Connector – Grey

•	C Connector – Green

connector-pinsb2-b29

Pins

Each connector has pins numbered from 1 to 40 organized into five rows. The pin number is visible on the wire side of the connector once the plastic cover is removed.

For each connector large pins are used on the top and bottom rows; small pins are used in the middle three rows.

Accessing Connector Pins

connector-pin-removal

To either insert or remove connector pins you first must slide the white plastic surround upwards slightly to unlock the pins.

Inserting Pins

connector-tool

Crimp the pin onto the wire using a crimp tool. We recommend a Molex tool with a 1.6mm diameter crimp.

connector-b2

First ensure you have the correct cavity – it is very difficult to remove a pin once in place. To insert the pin push, it in with the open side of the crimp upwards, until the pin clicks in place.

Once finished move the connector white plastic surround back into position to lock the pins in place.

Removing Pins

Removing pins is very difficult without the correct tool. A very fine screwdriver can usually be used as a removal tool.

The tool is inserted from the ECU side of the connector to lift a sprung plastic catch while pulling on the wire from behind. Do not use much force on the wire, otherwise to pin will dig into the plastic catch and the pin will be very difficult to remove.

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