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Wiring/Sensor Probelms.

Discussion in 'ECU's, Electronics, and Tuning' started by utn, Nov 13, 2004.

  1. utn

    utn Member

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    I'm having a few problems with my sensors and or wiring in my motor car and It's really buggin me.

    My current setup is this. '89 CRX DX w/ B16A swap and a PR3 ECU.
    My check engine light is on and my ECU is giving me the following codes.

    I recently replaced my Intake air temperature sensor, or so I think. It was the sensor that is on the intake manifold. But the ECU still says that its not working properly, so I think it could be wiring problems, here is a picture of the sensor location that I did replace http://www.pbase.com/13898487/image/36287242

    "2) Oxygen sensor "B" - Defective circiut or unplugged/ Defective sensor"

    Is the Oxygen Sensor "B" the sensor that is on the exhaust right beneath the driver? And how can i check to make sure its working properly, or not. It is plugged in. :D (at least on the exhaust pipe it self)

    "10) IAT (Intake Air Temperature)sensor- Defective circuit or unplugged/Defective sensor" ? http://www.pbase.com/13898487/image/36287242 ?

    "14) IAC (Intake Air Control) Valve- Defective circuit or unplugged / Defective sensor"

    "23) Knock Sensor - Defective circuit or unplugged / Defective sensor"

    Can someone try to run me through on checking these things my self, it would be a great help to me.

    Thanks a lot,
    Scott
     
  2. pissedoffsol

    pissedoffsol RETIRED

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    that is not the IAT. IAT is on the back of the manifold by the throttle body or on the throttle body itself depending on the car.

    2nd o2 is your 2nd o2. you need to wire it up. obd0 use 2 o2 snesors, 1 for cyls 1 and 3, 1 for 2 and 4. see the reference section for ecu pinouts. C8 is where the 2nd o2 needs to go. but again, go to te reference section thread "ecu pinouts" for more detials.

    iac is also by the iat o the manifold in the back. check that you didin't swap the plugs between these two units. its a common problem as they are both 3 wires if memeory serves.

    knock, you need to wire up as well. the sensor is in the back of the block to the driver side of the oil filter. wire it up, again according to the pinout. your oem wiring doesn't have this.
     
  3. utn

    utn Member

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    I can't find my IAT sensor, I see the IAC valve and its plug and I see the Throttle Posision Sensor and its plug, but thats all. The only other sensor I can find on my intake manifold is the one sensor I have circled in that picture, and as you say it is not the IAT sensor. Where should it be? My IAC valve has a 2 wire plug, not a 3 wire. (if that helps)

    My knock sensor has wires that just go into a jumble of other wires and I'm not sure how to trace the wire to wire it up. So I'm lost here too.

    I don't know where to start with the Oxygen Sensor "B", I don't know where it's located.

    Can anyone help me and my lack of knowledge :(


    Thanks in advance for any help you can give me
    -Scott
    :worthy:
     
  4. civicious

    civicious FüK-VTEC VIP

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    um....B....the IAT is on the #1 runner on the IM....you're thinking of the fast idle valve on a GSR. the thing he has circled in the pic IS the intake air temp sensor...

    IAT and IACV are both 2-wire sensors. The IAT should be green/red. I'm not sure of the colors on the IACV, but it should be on the same extension of wire as the TPS. I think the TPS and the IACV are the only 2 plugs on that particular extension from the wiring harness.


    On the B16A exhaust manifold, the 2 o2 sensors should be right next to each other. If they aren't, you don't have an obd0 exhaust manifold.
     
  5. utn

    utn Member

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    I have a aftermarket full exhaust kit (i dont know anything about it because thats how it was when i bought the car) I can find only 1 O2 sensor on my exhaust, and its not on the manifold part, its beneath the foot pedals on the horizontal section of the exhaust pipe. I swapped the connectors on the IACV and the IAT sensor, IAT getting the red and green wires while the IACV got black and red i think. The ECU is still giving me the same codes and the engine runs the same.

    Any ideas? <_<

    Thanks,
    Scott
     
  6. civicious

    civicious FüK-VTEC VIP

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    the IAT sensor might be bad.

    Did you plug the right plug into the IACV? if it was long enough to reach to the IAT sensor, it probably isn't the IACV...you've probably got the power steering pressure plug plugged in. Back behind the IM there should be another 2-pin connector somewhere...on the same extension as the TPS. Plug that one into the IACV.
     
  7. utn

    utn Member

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    I don't think my sensor is bad because I bought a new one on eBay and it looked to be almost brand new (trusting that the seller didnt send me a bad one). Is there a way to check the sensor to see if its good? I think I migh have some bad wiring, so that's what im going to check next.

    Thanks for the help,
    Scott
     
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