Solving Intermittent 4ws on 92+ preludes

First of all I can not take credit for this FIX, the information I used was provided by a honda-tech member by the name of wstef, and his original post can be found here http://honda-tech.com/zerothread?id=886363 I did however complete this today, and took photos that may help some of you accomplish the task, and that is the reason for this post.

This FIX may not help everyone that is having issues with their 4ws. 4ws may become intermittent for any number of reasons, relating to it's sensors and cicuitry. However this fix has proven helpful to a number of prelude owners that suffer from intermittent 4ws, mostly those reporting a 4ws error code of 62. this does not appear to be a one-off chancey thing with only "some" 4ws units. It appears that NEC, (the manufacturers) of the unit did a piss poor soldering job on the relays, and age and time, cause them to become cracked - giving the intermittent 4ws. - I hope they fired that pesky robot.

First of all I'm not going into detail of how to remove the 4ws unit itself (it's a bitch, atleast I thought it was a pain in the arse) because if you can't figure that out, you probably shouldn't be messing around with the guts of the 4ws unit in the first place. as Wstef did - I also recommend your first step is to disconnect your battery. Finally I take no responsibility in how you might use this information to your advantage or "in a soldering nightmare" disadvantage.

Tools Required

10mm socket (w/ extension helps)
philips screw driver
soldering iron w/ solder
Large Book and Newspaper (or similar non-static'y items)
magnifying glass (not essential but nice)

With the CAR battery disconnected

1) remove the 4ws unit from car, I'm not going to go in great detail about this, basically you have to remove the rear left seat to gain access to it - information about removing your rear seats can be found in the helms page 20-41 - the 10mm will come in handy.

2) once you have the unit removed place it on a suitable work space with cooling FINS up, and a book on it's left hand side.

http://members.shaw.ca/palev/4ws-1.jpg

I chose a sizeable book (as shown below) - and I recommend you do the same, you'll see why shortly

http://members.shaw.ca/palev/4ws-2.jpg

3) Remove the 6 screws as shown in red

http://members.shaw.ca/palev/4ws-3.jpg

4) Gently open this cover (from the RHS of the unit - like turning a page in a book) and place it on top of the Large book next to the unit. The green arrow indicates the paper ribbon connector - you have to be very gentle it is hardwired to the boards so you can't disconnect it. The red circles indicate the next 5 screws you will have to undo....the one furthest right is a Larger screw than the others.

http://members.shaw.ca/palev/4ws-4.jpg

5) remove the heat shield...voila more electronics.

http://members.shaw.ca/palev/4ws-4.5.jpg

6) Next remove the 25 screws as indicated in RED, they are of various sizes but pretty self-explanatory so It would be hard to mess them up. The yellow arrows indicate the "troublesome relays" (well their solder points atleast) that give intermittent 4ws.

http://members.shaw.ca/palev/4ws-5.jpg

7) lay some newspaper/cardboard, or anything non-static'y over the other electronic board. once again, like a book - turn the page, so that the bottom of the troublesome relays are exposed. remember to be careful of that paper ribbon. YOIKES!...In case you get lost looking at circuitry I've outlined the problematic solder points in red for you.

http://members.shaw.ca/palev/4ws-6.jpg

here is another pic of the Yummy 4ws Sandwich.

http://members.shaw.ca/palev/4ws-7.jpg

8) Resolder those points and you should be good to go!, don't burn yourself - like my stupid ass did - it really hurts ): still does.

9) reassemble the unit (reverse order of diassembly)

10) put unit back in car, and connect

11) reconnect the battery terminals

12) rock that 4ws like the day you bought it.