To those that read and respond, thanks. IF your help leads to me fixing this annoying problem, I'll paypal.com you 15 bucks!

Car is an 94 civic ex with a B18B. Running a p75 chipped ecu with an afc as well as 450cc injectors. OBD1 ECU, Car, Motor, wiring harness.

The car has always had this code since i bought it a month ago. i've come up wtih a code 1 Check engine light [CEL]. The CEL comes on even after i reset the ecu and simply put the key in the on position (motor doesn't even have to be run). Code 1 is defined as o2 sensor - check heater, wires, and sensor

Here is what i've done so far to diagnose:
[remember the o2 sensor is an obd1 4-wire Green/black/white/white]

Bought a brand new 02 sensor.
Checked 3 of 4 wires. I'll name the wires on the engine harness side (not 02 sensor side).

White (sensor output)wire works as when motor is warmed up, i read a fluctuating 0.1-0.9 volts.
checks out as it connects to the tps and intake temp sensor, and no error codes there and those work.
Yellow/Black (12V) wire works as i receive 12-13V from this wire with the ignition on.

the 4th wire is an orange/black wire (heater control) I have no idea how to diagnose this wire. Any tips?

I've also changed ecus, and same problem. It's just wierd how the ecu pops up the code w/o the motor even being on. TO those that help out. thanks. You can also AIM me on ILOVEFUZZZ if you have the time.

Danny

 

Is it a quick blink or a long blink? A long blink will be code 1 Primary Oxygen Sensor (O2) and quick blink will be code 10 Intake Air Temp Sensor (IAT).

 

Long Blink. THus the oxygen sensor.

 

Did the car have or had a A/F meter? That and double check the AFC installation.

Just trace along from the ECU bad and check the wiring from there. Sounds like

you have an open connection between the O2 sensor and the ECU.

Everytime you turn on the car the ECU goes thru a self-diagnostic wether you

crank the car or not, like a PC during bootup.

 

I didn't have an air fuel before. WHat i did was re-do all 4 wires and i still have the same result.

I ran directly the white wire D14 and the orange/black wire (A6) to the ecu. The other wires yellow/black (12V/A25pin) and the green/white wire (D22pin) i spliced in.

If i want, can i just run the green/whtie wire to a seperate ground? Can i run the yellow black wire to an independant 12V?

How do i diagnose the orange/black (A6) wire? Does anyone know how it actually functions? Is it a dynamic ground?

Thanks

Danny

 

Thinking it over, there are only two wires the ecu sees regarding the 02 sensor. one is the heater control, the second is the actual 0xygen sensor signal (white wire). Since the heater control light isn't coming on..i'm going to rule that out...i'm going to have to figure out this white wire more then.

 

here is a quote from the haynes manual:
"if the engine reaches operating temperature and if the oxygen sensor is producing a steady signal voltage below 0.45 volts at 1,500rpm or more, the ecu will set a code 1"

My car is fine on that area.

it also says "the o2 sensor will produce a setady voltage signal at first (open loop) of approx 0.1-0.2 volts with the engine cold. When the engine reaches operating temperature, the sensor will flucuate between 0.1 -0.9 volts"

THe funny thing here is that when my 02 sensor is in open loop (cold) it starts off at 0.9 volts, and then after a bit it will cycle throguh 0.1-0.9 volts. Ideas?

Danny

 

I think your chasing the wrong code. Long blinks are tens and short blinks are ones. Typically when a O2 sensor code is stored, the ECU no longer uses input from O2 and just runs in "open loop". You said the O2 volts are fluctuating as they are supposed to. If it's fluctuating than the O2 sensor is working.Try disconnecting the TA (air temp) sensor and see if a second code sets......3gdude

 

Get rid of those 450 injectors...way to much for your setup unless your boosted

 

I like a good challenge, you didn't bail on us did you????......3gdude

 

Whoa boy is there confusion up in this thread.

Code 1 = one SHORT blink which is the O2 Prim Sensor. Therefore being the WHT wire leading to the D14 pinout.

Code 10 = one LONG blink. I see that you have stated you have one long blink on the diagnostics when the service connector is jumped.

Code 10 is the IAT (intake air temp sensor) which is a WHITE sensor located on the Intake Manifold. It is a two wire plug that has the following:

There is a Grn/Wht wire which is the IAT sensor ground (which also by factory is spliced with the Grn/Wht wire on the O2 sensor going to the D22 sensor ground pinout).

The other wire is a Red/Yel wire leading to the D15 pinout. Sounds like there is an open circuit/break in the wire, or you have a bad IAT or ungrounded IAT.

What you will need to do is to grab a digital multimeter and test for open circuits between the Red/Wht wire on the plug, and the D15 pinout on the D plug harness. If it shows that it is shorting out, then you have a complete connection using the digital multimeter.

With the other wire being the Grn/Wht wire, just grab the multimeter once again and verify you have a complete circuit/short to the D22 pinout on the D plug harness.

If it shows open circuit, then trace the break in the wire using the multi meter, or hardwire it to the proper pinout at the ECU and see what happens.

If wires show good, then replace the IAT. It's a simple relacement as there is two screws just holding it on.

Make also sure you have clear the codes on the ECU by pulling the ECU (PGM-FI) 15A fuse under the hood for 30 seconds, or you may also disconnect the negative terminal on the battery for 30 seconds.

That should fix your problem.

HTH.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by poison &raquo;</TD></TR><TR><TD CLASS="quote">Whoa boy is there confusion up in this thread.

Code 1 = one SHORT blink which is the O2 Prim Sensor. Therefore being the WHT wire leading to the D14 pinout.

Code 10 = one LONG blink. I see that you have stated you have one long blink on the diagnostics when the service connector is jumped.

Code 10 is the IAT (intake air temp sensor) which is a WHITE sensor located on the Intake Manifold. It is a two wire plug that has the following:

There is a Grn/Wht wire which is the IAT sensor ground (which also by factory is spliced with the Grn/Wht wire on the O2 sensor going to the D22 sensor ground pinout).

The other wire is a Red/Yel wire leading to the D15 pinout. Sounds like there is an open circuit/break in the wire, or you have a bad IAT or ungrounded IAT.

What you will need to do is to grab a digital multimeter and test for open circuits between the Red/Wht wire on the plug, and the D15 pinout on the D plug harness. If it shows that it is shorting out, then you have a complete connection using the digital multimeter.

With the other wire being the Grn/Wht wire, just grab the multimeter once again and verify you have a complete circuit/short to the D22 pinout on the D plug harness.

If it shows open circuit, then trace the break in the wire using the multi meter, or hardwire it to the proper pinout at the ECU and see what happens.

If wires show good, then replace the IAT. It's a simple relacement as there is two screws just holding it on.

Make also sure you have clear the codes on the ECU by pulling the ECU (PGM-FI) 15A fuse under the hood for 30 seconds, or you may also disconnect the negative terminal on the battery for 30 seconds.

That should fix your problem.

HTH.</TD></TR></TABLE>

good call.

now the question is whether or not you are the recipient of the 15 dollar prize.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by poison &raquo;</TD></TR><TR><TD CLASS="quote">Whoa boy is there confusion up in this thread.

Code 1 = one SHORT blink which is the O2 Prim Sensor. Therefore being the WHT wire leading to the D14 pinout.

Code 10 = one LONG blink. I see that you have stated you have one long blink on the diagnostics when the service connector is jumped.

Code 10 is the IAT (intake air temp sensor) which is a WHITE sensor located on the Intake Manifold. It is a two wire plug that has the following:

There is a Grn/Wht wire which is the IAT sensor ground (which also by factory is spliced with the Grn/Wht wire on the O2 sensor going to the D22 sensor ground pinout).

The other wire is a Red/Yel wire leading to the D15 pinout. Sounds like there is an open circuit/break in the wire, or you have a bad IAT or ungrounded IAT.

What you will need to do is to grab a digital multimeter and test for open circuits between the Red/Wht wire on the plug, and the D15 pinout on the D plug harness. If it shows that it is shorting out, then you have a complete connection using the digital multimeter.

With the other wire being the Grn/Wht wire, just grab the multimeter once again and verify you have a complete circuit/short to the D22 pinout on the D plug harness.

If it shows open circuit, then trace the break in the wire using the multi meter, or hardwire it to the proper pinout at the ECU and see what happens.

If wires show good, then replace the IAT. It's a simple relacement as there is two screws just holding it on.

Make also sure you have clear the codes on the ECU by pulling the ECU (PGM-FI) 15A fuse under the hood for 30 seconds, or you may also disconnect the negative terminal on the battery for 30 seconds.

That should fix your problem.

HTH.</TD></TR></TABLE>

Damn, you beat me to it!! I used to have code 1, it was my B&M fuel pressure regulator was set too high after I install a new fuel pump. I reset the ECU, lower the fuel pressure, and wiped clean the O2 sensor haven't seen the code since.

 

If you read my post.....and he read my post......he probably already found the Air Temp sensor unplugged .......3gdude