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.