My daughter blew her motor on her 2002 Civic so we replaced the motor. She now has a D17A2. I've also replace her wiring harness (EX) and ECU (EX) so that they all correspond to each other. The problem is there is no plug for a secondary O2 Sensor on the wiring harness and I don't have a plug on the cabin harness. I connected the secondary O2 plug straight into the ECU and now I get a P0141 code. I have a hand held scanner and can reset it but without fixing it, it just comes right back on. here is how I hooked it up:

The O2 sensor (secondary) has 4 wires: 2 white, 1 black, and 1 grey.

White: Piggy backed to a blk/yel on Connect A, pin #3 (power source)
White: Pinned into Connector E, pin #6 (Secondary O2 Sensor Heater Control)
Black: Pinned into Connector E, pin #2 (Secondary O2 Sensor)
Grey: Grounded to the Thermostat Housing

I am looking for any help on this. I've searched till I can't search anymore and I hooked up based on what I've read. I think I might have actually reached the end of the internet.

thanks for your time and I so look forward to any guidance.

 

Here's the wiring pinout:

01-03 Honda Civic EX M/T ECU Pinouts

Connector A (31 Pins) 01-03 Civic EX M/T
1-blk/wht-Primary O2 sensor heater control
2-yel/blk-Power Source
3-yel/blk-Power source
4-blk-Power ground
5-blk-Power ground
6-wht-Primary O2 sensor
7-blu-Crankshaft position
8-yel-Sensor return volt
9-red/blu-Knock sensor
10-grn/yel-Sensor ground
11-grn/wht-Sensor ground
12-blk/red-Idle air control valve
13-wht/blk-EGR Valve position VTEC ONLY
14-blk/wht-Secondary O2 sensor heater control
15-red/blk-Throttle position sensor
18-wht/grn-Vehicle speed sensor
19-grn/red-MAP Sensor
20-yel/blu-Sensor Voltage Supply
21-yel/red-Sensor Voltage Supply
23-brn/yel-Logic ground
24-brn/yel-logic ground
25-wht/red-Secondary O2 Sensor
26-grn-Top dead center sensor
27-brn-Igniton coil 4
28-wht/blu-coil 3
29-blu/red-coil 2
30-yel/grn-coil 1

Connector B (24 Pins) 01-03 Civic EX M/T
2-yel-Fuel injector 4
3-blu-Injector 3
4-red-Injector 2
5-brn-Injector 1
6-grn-Radiator fan control
7-red/blk-A/T Pressure control solenoid valve A
8-red/wht-Engine Coolant sensor
9-blu/blk-VTEC Oil pressure switch VTEC ONLY
10-wht/blu-Alternator L Signal
13-wht/red-Alternator FR Signal
14-blu/red-EGR Valve VTEC ONLY
15-grn/yel-VTEC Solenoid valve
16-blk/red-A/T Pressure control solenoid valve B
17-red/yel-Intake air temp sensor
18-wht/grn-Alternator control
21-yel/blu-EVAP Canistor purge valve

Connector E (31 pins) 01-03 Civic EX M/T
1-grn/yel-Immobilizer fuel pump relay
2-wht/red-Secondary O2 Sensor EX Only
3-brn/yel-Logic ground
4-pnk-Sensor ground
5-yel/blu-Sensor voltage source
6-blk/wht-Secondary O2 sensor heater control EX Only
7-red/yel-PGM-FI main relay 1
9-yel/blk-Ignition input signal
12-blu/orn-Cruise control signal
13-wht/blu-Interlock control unit
14-lt grn-Fuel tank pressure sensor
15-grn/red-Electrical load detector
16-lt grn/blk-Power steering pressure switch
18-red-A/C Clutch
20-blu/red-EVAP bypass solenoid valve
21-lt grn/red-EVAP Canister shut valve
22-wht/blk-Brake pedal position switch
23-lt blu-K line
24-yel-Multiplex control unit comm line
26-blu-Engine speed pulse
27-red/blu-Immobilizer code
29-brn-Service check signal
30-red/wht-Write enable signal
31-grn/orn-MIL or check engine light enable

Also, how did you go about wiring it? Did you cut the connector off and solder the wires? If so, you possibly threw off the voltage and that's what's causing the check engine light to come back on.

 

^^ Really? That throws off the voltage? What do you do then, re-pin with a single piece of wire?

 

Ok really old post but did it work or what.i have mine wired up an
d everything is good but i have no ground at the ecu for the heater control circuit. The heater control has two wires 12v and ground at ecu,well no ground at ecu.did you have same issue or no