ST205 IC / Code 54 Elimination circuit

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ST205 IC / Code 54 Elimination circuit

Postby scothaniel » Mon Apr 17, 2006 5:58 pm

Thanks to Greg (zblu81) , I was able to figure out the wiring combination to eliminate the code 54 error by fooling the ECU into thinking that the pump system is working fine. Here is the basic circuit I used - and it worked great! :

Image

The diode just keeps the power signal from back tracking to the ECU. May not be needed, but for $1 I'll play it safe.

For those of us without the manifold air temp sensor (tham), you can wire in a 1.5-3K resistor to make the ECU think the post intercooler air temp is nice and cold.
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Postby Gary » Mon Apr 17, 2006 6:06 pm

Few questions,
Is that NO type relay?
Which direction the diode is connected?
Cathode is on the top or bottom?
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Postby CMS-GT4 » Mon Apr 17, 2006 6:12 pm

What about doing this at the ECU? Can I just bridge the wires through this resistor and prevenmt the code? I do not have wires in my engine bay for this since i used the 185 harness.
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Postby scothaniel » Mon Apr 17, 2006 6:28 pm

Relay is a standard 4-wire Normally Open relay.

Diode allows flow from ECU to Ground ( I can never remember which end the cathode is on, I always have do a continuity check).

What about doing this at the ECU? Can I just bridge the wires through this resistor and prevenmt the code? I do not have wires in my engine bay for this since i used the 185 harness.


I did this at the ECU. I put the light bulb in the glove box (be careful, it gets really hot) and the relay is sitting next to the EFI relay. Most of the wire are under 12" long.
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Postby Gary » Mon Apr 17, 2006 6:43 pm

scothaniel wrote:Diode allows flow from ECU to Ground ( I can never remember which end the cathode is on, I always have do a continuity check).

In that case, it the cathode should be on the top.

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Postby CMS-GT4 » Mon Apr 17, 2006 6:50 pm

I was going to wire in my tham. Should I follow the same methods? Also, is the bulb needed? And what relay am I conncting to?

I am still a wiring noob. Thanks for you help.
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Postby scothaniel » Mon Apr 17, 2006 7:16 pm

Pic updated, thanks!

I would assume that you could use a 15 ohm / 10 watt resistor in place of the bulb, but I know the bulb works.
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Postby Gary » Mon Apr 17, 2006 7:18 pm

From what I understand, the bulb is a must.
May be a ceramic resistor world work too?
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Postby CMS-GT4 » Sat May 06, 2006 7:13 pm

What wire should I tap into for a 12V power source? I think I have all the bits I need.

I am also going to post pics of what I put together.

What purpose does the bulb serve?
Coldiron
92 st185 (205 swap) | 03 350Z Track (sold) | 13 Pilot | 17 Mazda3
www.noritoy.com | noritoy.deviantart.com | http://www.alltrac.net/phpBB2/viewtopic.php?f=44&t=19891
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Postby CMS-GT4 » Thu Jun 08, 2006 11:30 pm

Here is a link to another solution to this.

http://www.gt4dc.co.uk/website/howtos/st205_code54.php
Coldiron
92 st185 (205 swap) | 03 350Z Track (sold) | 13 Pilot | 17 Mazda3
www.noritoy.com | noritoy.deviantart.com | http://www.alltrac.net/phpBB2/viewtopic.php?f=44&t=19891
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Shorting???

Postby Acadian alltrac » Tue Jun 20, 2006 2:48 pm

I have a question about the wiring, aren't M+ and M- going to be shorting.

Thanks
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Postby CMS-GT4 » Wed Jun 21, 2006 3:06 pm

I am not sure myself, but I think this is how they are linked at the harness from the factory. So, if it is, they should not.

I am not much for wiring myself, and hope I have gathered enough info from this thread to do this right.
Coldiron
92 st185 (205 swap) | 03 350Z Track (sold) | 13 Pilot | 17 Mazda3
www.noritoy.com | noritoy.deviantart.com | http://www.alltrac.net/phpBB2/viewtopic.php?f=44&t=19891
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Postby Acadian alltrac » Thu Jun 22, 2006 3:54 pm

I used the 185 harness to so let me know how it goes if your done before me. the only thing am missing is the light
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Postby Acadian alltrac » Fri Jul 07, 2006 9:56 pm

Hi,

I just wanted to let you know that I did the circuit with the light, works fine for me! No more check engine (code 54 and 23) and its been like 2 weeks now. Now running full boost for the first time!! It's great!

Thanks,

André
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Postby CMS-GT4 » Fri Jul 07, 2006 10:18 pm

Any pics?
Coldiron
92 st185 (205 swap) | 03 350Z Track (sold) | 13 Pilot | 17 Mazda3
www.noritoy.com | noritoy.deviantart.com | http://www.alltrac.net/phpBB2/viewtopic.php?f=44&t=19891
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