Thread: Self diagnosis, how to switch modes

I've been reading my FSM thoroughly and it's for the B13 and N14 model, with the SR engine.

(This FSM is not listed on the FTP link somehow, but a lot of others are, so I'm not sure the following info is helpful: It's in Vol.1 EF & EC page 412)

As what I understand from what the FSM is saying, I only need to use a paperclip, connect it between CHK and IGN on the diagnostic connector located in the dash and it will jump to Mode II (Mode I is the regular, check engine light we all get to see when we start our cars).

I would like to know about stored trouble codes or if the ECU has some error code for me prepared. Is it just me that I'm weary of sticking a paperclip in the diagnostic connector or are we all. I couldn't find anything about this on this forum, but with Googling for it I found this page: ECU Fault Checking

That's actually confirming it's ok to put a paperclip in the diagnostic connector and from what I make of the FSM it's no difference when using a ''suitable harness'' for it.

But I would like to know for sure, a blown ECU is kinda disaster and if it can be done, then other forum members are probably interested too.

The problem is its too large for a free sharing site, the skydrive limit is 50Mb where i have posted lost of manuals and info....
I asked for input on preference to handle this and lost interest because no one answered or gave an opinion.
yes that's what it says on that page, I agree, but take no notice of me because I have not attempted this !!

They are indeed huge.

I managed to get them from:

http://www.icostarica.net/download/Nissan%20B13%20and%20N14%20Service%20Vol%201%20-%20100NX%20NX1600%20NX2000%20Sunny%20Sentra%20GA16DE%20SR20DE%20SR20DET.zip

http://www.icostarica.net/download/Nissan%20B13%20and%20N14%20Service%20Vol%202%20-%20100NX%20NX1600%20NX2000%20Sunny%20Sentra%20GA16DE%20SR20DE%20SR20DET.zip

Now the link might look like being down or be a bit slow, then it can be fast again but with a bit of patience you will get them.

Maybe you can put the links in the right place?

But I'm kinda surprised nobody seems to have tried before getting the ECU in Mode II? I'm like 99% certain it won't hurt, but some positive feedback would be great for all forum members!

Why use a paperclip? There's a diagnostic switch on the ECU itself. Grab a flat head screwdriver, put the key into the ON position (don't start the car), then rotate the screw on the ECU fully clockwise, count two seconds, then fully counter clockwise. You will then see your MIL on the dash flash with cooresponding codes. if 5 long 5 short, no codes detected.

To exit mode II, simply turn the screw clockwise fully, then counterclockwise again.

He has a B13, does this also apply for a B13?

yes it does.

I did read about the ECU having a screw, but I didn't properly understand what it was used for. Now I know what it does I'll be screwing it tomorrow.

Thanks!

Just make sure you screw it back when you're done - the ecu strongly states that the car should not move with it in the wrong position...not sure why but if the fsm says so, do it

I said I would check this out the next day but of course nothing went as planned this weekend.

First I removed the interrior part for taking a look at the ECU:



No screw!

So I took my ''suitable harness" and managed to get the ECU in ModeII:



And I got the errorcodes and also checked the working of the O2 sensor.

Interesting. I would have thought that surely there was a screw on the OBD1 ECU's.

Good to know about the whole paperclip thing. Should probably add some keywords to your thread so that when others search, they will be able to find this thread easily.