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SRS unit internal failure (DTC code 5-2)

  #1  
Old 10-04-2008, 06:24 PM
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Join Date: Oct 2008
Posts: 46
Default SRS unit internal failure (DTC code 5-2)

My SRS light has been on for the last week, i tried to reset it a few times, but even after successfully clearing the memory (double blink), the light immediately comes back on...

I ran a diagnostic using the 2 pin connector under the glove box and it seems i have a 5-2 error (internal failure of the srs unit).

I disconnected today my airbag (be extra careful when u do this, first disc the battery, and wait for at least 5 - 10 minutes) and i removed the srs unit.

Before spending 500+ bucks on a new unit, I was thinking why not try to fix the old unit, meaning checking the circuit board and reflowing the connections (i did this in the past with a radiator fan timer and it worked like a charm)

Did anyone ever try this before ? I will not modify the pcb in any way, i just plan to reflow the joints...

Any help would be appreciated, i hope somebody can tell me what exact part of the srs unit the code 5-2 refers to...

i will let you know how it goes anyway
 
  #2  
Old 10-05-2008, 06:14 AM
TexasHonda's Avatar
Super Moderator : And A Texan
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Location: Katy, TX
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Default RE: SRS unit internal failure (DTC code 5-2)

Suspect parts are surface mount components. If you get a really powerful magnifying glass, you can examine solder jts for signs of cracks and loosening.

Never worked on a SRS board, but have fixed a clock which had 4-5 surface mount resistors, and at least two were barely still in place due to solder failure. Delicate work so a small (20-25 watt) pencil type soldering iron is essential.

good luck
 
  #3  
Old 10-05-2008, 02:36 PM
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Join Date: Oct 2008
Posts: 46
Default Still doesn't work

ORIGINAL: TexasHonda

Suspect parts are surface mount components. If you get a really powerful magnifying glass, you can examine solder jts for signs of cracks and loosening.

Never worked on a SRS board, but have fixed a clock which had 4-5 surface mount resistors, and at least two were barely still in place due to solder failure. Delicate work so a small (20-25 watt) pencil type soldering iron is essential.

good luck
I opened the srs unit today and reflowed most solder joints... this was way more complicated then working on the fan timer unit, there are hundreds of tiny components, all are very close to each other and this pcb is double sided, meaning there are joints on both sides of the board... it took about 1 hour and half.

So after finishing the resoldering, i put the unit back, reconnected everything and i reset the srs (3 times), but, the light came back on everytime.

I ran again a diagnostic using the 2 pin connector, and the same unique error came back (5-2), so at least, it seems i didn't destroy anything else while playing with the pcb.

I won't start looking for a new srs unit yet, next, i plan to replace 3 big capacitors that are installed on the board, from my experience, these things are often the first to fail.

I will let you know if i can fix it.


[IMG]local://upfiles/18533/D987D838634346FA940E56D13698CD1E.jpg[/IMG]

[IMG]local://upfiles/18533/1914D96B70A74A5ABC42173AAB83C72E.jpg[/IMG]

[IMG]local://upfiles/18533/B5A107B2C23F48E3A0E73D59D7F9DB9D.jpg[/IMG]

[IMG]local://upfiles/18533/F19A1F69881F476CBBD89F8675E091C2.jpg[/IMG]

[IMG]local://upfiles/18533/6C93F8B0BFF94C44878941DA73EA7DD4.jpg[/IMG]
 
  #4  
Old 10-05-2008, 04:03 PM
Thread Starter
Join Date: Oct 2008
Posts: 46
Default The usual suspects

Took all capacitors out, i'll get some fresh ones tomorrow, these things cost less than 1 dollar, worth a try before heading to the stealership.

[IMG]local://upfiles/18533/3A0E551B57204FA6BA84795E0A18D8F6.jpg[/IMG]
 
  #5  
Old 10-06-2008, 05:11 PM
Thread Starter
Join Date: Oct 2008
Posts: 46
Default Still not working

So i got the new capacitors today (6 capacitors for about 4 dollars).

I couldn't find an exact match but i bought ones with higher voltage and capacity, which is ok.

The new capacitors were "taller" then the old ones, i had to lay them flat on the board so that they can fit inside the srs unit... doesnt look nice but it does the trick, another solution would have been to drill 3 holes on the srs unit cover and let the 3 big capacitors stand through. i chose the easy solution (1).

Anyway, i put the unit back in the car, reconnected the airbag, reset the srs a few times, but it was useless, the same code comes back (5-2).

I have no idea what to try next, i am not an electronician, so i guess unless someone from this forum can give some useful tip, i will start looking for a replacement unit (ebay, junkyards, ultimately the stealership) or i will simply remove that damn lamp from the cluster.

I attach herewith a few pics of today's capacitors' replacement for reference.



[IMG]local://upfiles/18533/2863CBDA5E4C4DF1A9BA7F9027AD49FF.jpg[/IMG]

[IMG]local://upfiles/18533/F7CC0570928E451E94A9E3AC904E5E45.jpg[/IMG]

[IMG]local://upfiles/18533/0D077348D9D343F39321D7AD64C16955.jpg[/IMG]

[IMG]local://upfiles/18533/F7FAF347D29B4BFAA15D4B45F798D992.jpg[/IMG]

[IMG]local://upfiles/18533/211BC249969D4FA28C3C10A932C60424.jpg[/IMG]
 
  #6  
Old 10-06-2008, 06:39 PM
Super Moderator
Join Date: Sep 2006
Location: Houston, TX
Posts: 13,113
Default RE: Still not working

IMO, I would not change the setup with the capacitors on the SRS unit, because the airbags may not work properly. Having the airbags accidentally deploy can seriously harm to you.

You have to clear the SRS code that is stored. I forgot to plug in my airbag connector and the SRS light continued to stay on after I plugged the airbag back in. The procedure is a bit more complicated than the one for the check engine light. You have to find the dummy connector for the air bag (on driver's side, under the dash on the same wall as the fuse box). You basically have to jump, then unjump the connector in the proper amount of time clear the SRS unit. I attached a procedure to reset the SRS.






[IMG]local://upfiles/5767/4CE51AD2E70843CF8A9A285AC0B9DC4D.jpg[/IMG]
 
  #7  
Old 10-06-2008, 06:51 PM
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Join Date: Oct 2008
Posts: 46
Default RE: Still not working

ORIGINAL: PAhonda

IMO, I would not change the setup with the capacitors on the SRS unit, because the airbags may not work properly. Having the airbags accidentally deploy can seriously harm to you.

You have to clear the SRS code that is stored. I forgot to plug in my airbag connector and the SRS light continued to stay on after I plugged the airbag back in. The procedure is a bit more complicated than the one for the check engine light. You have to find the dummy connector for the air bag (on driver's side, under the dash on the same wall as the fuse box). You basically have to jump, then unjump the connector in the proper amount of time clear the SRS unit. I attached a procedure to reset the SRS.






[IMG]local://upfiles/5767/4CE51AD2E70843CF8A9A285AC0B9DC4D.jpg[/IMG]
Yes you are probably right about not messing with the unit.

The idea is that usually capacitors can be replaced with bigger ones with no problem, but what applies to radio tuners might not work for airbags, and i'd rather not be the guinea pig.

I know about the way to reset the srs using the yellow 2 pin connector (thanks to forums like this one), this is what i have been trying before/after altering the srs unit, but everytime, after the procedure and the final double blink, the light comes back again (1 or 2 seconds after the double blink).

I will probably look for a replacement unit, but i am still very curious to know what could have been broken inside that unit, it seems this is very common and i wonder if it is a "physical" problem at the pcb or more of a programming issue...

Thanks for the help.
 
  #8  
Old 10-07-2008, 12:22 PM
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Join Date: Oct 2008
Posts: 46
Default RE: Still not working

Guys,

I found a replacement srs unit online, the case looks exactly like mine and is also from a 96-97 accord.

The thing is, there are a few minor differences :
- the last 3 digits of the model number are not the same : mine is 77960-SV4-Y72, the one for sale has number : 77960-SV4-A93.
- my srs unit has a big D stamped next to a bar code, the new one has an A instead.
- the sticker is upside down compared with mine...

I found a few posts from people who could fix their airbag issue by replacing their srs units with ones they got at junkyards...

I am asking those people and everybody else : do i need to look for a SRS unit with EXACTLY the same model number ? is it really a model number or more like a serial number ?

Thank you

ps : attached is a pic of my unit vs the one on sale




[IMG]local://upfiles/18533/A600467AF8DE46F69A9428C073C03DA8.jpg[/IMG]
 
  #9  
Old 08-04-2013, 12:23 PM
Join Date: Aug 2013
Posts: 3
Angry Honda Civic airbag code 5-2

I was having the same issue as some others were having. My Honda civic 2005 LX automatic has its airbag light on for a couple of weeks. I first tried to reset it but was unsuccessful so I checked the battery and it was bad. So after I changed the battery the light was still on. I tried to reset it using the paper clip method but still same. I found out the code was 5-2 (internal failure of SRS unit). So I decided to change the SRS unit and changed it but the light never came off. I also tried changing the instrument panel just if that helps but still same. Then I found out that the alternator might cause srs code but when it was checked the alternator was fine (14.4 volt with ignition on). The code is 5-2. Anyone has any idea? The Honda dealers couldn't figure it out so they say they need to replace the entire front for $2000 + labor. That is expensive. If anyone has any idea help please.
Thanks.
 
  #10  
Old 08-04-2013, 02:01 PM
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Super Moderator : And A Texan
Join Date: Feb 2007
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Default

Looks like the OP from this thread had no better luck than you.

Only thing I can suggest is be sure you are using the reset procedure correctly. I have read that it is tricky to get the timiing right, but I've not done a reset.

Some problems can take extraordinary patience and persistence to solve. This looks like one of those.

good luck
 

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