Witherspoon Seeks ECU Code Flash Advice

[Larry Witherspoon]

Hi Guys (and Dolls)

My Check Engine light started coming on a while back

Took it to my nearby ex factory Sube mechanic and he showed me how to
connect that little wire under the dash and read the code flashes

I was getting a Code 22 - Knock Sensor

And he had a convenient factory knock sensor which I bought

Well, I managed to get the old one out after removing only a couple
of vacuum hoses

Then, stupidly, I tried installing the new sensor, after attaching it
to the wire from the ECU which was already pretty brittle, but I
promised myself I would be careful...I didn't want to try connecting
the wires in the limited space I would have after installing the
sensor

Well the damn wire from the ECU broke right smack at the connector
attachment...nothing to splice to

So my mechanic gave me a free ticket into Ecology Auto Wrecking (pic-
a-part), and I found a couple of Legacys that had my wire, so for a
grand total of two dollars, I was ready to rumble.

So without much room to work with I spliced the new old junkyard wire
to what was left of my wire coming out of the firewall to the ECU.

Now this little wire is actually a mini coax, and I was careful to
check out how the factory installation was done because on my car the
outer wire seemed like it was broke off and just hanging out in the
air.

But sure enough, on both the junkyard cars, that wire goes nowhere,
and my factory service manual shows the wire terminating at the ECU
into two plugs, but the outer wire called the shield, goes nowhere,
not even to ground, so I guess it's a radio interference thing.

So I tried to be real careful, when I spliced the two wires (actually
four wires), to keep the inner and outer wires separated with heat
shrink tubing.

But when I got done the C.E. light was still on...shit

So I plugged in the code flasher wire under the dash and NOW it's
going crazy and I'm getting the following sequence;

22 - 11 - 14 - 15 - 16 - 17 - 22 - 11 - 14 - 15 - 16 - 17 - 22 -
repeat

Ideas anyone?

Larry ssspoon Witherspoon
92 Turbo Legacy
562-982-7720
310-439-4269

[Aerotech]

Wow...check all the ECU plugs, make sure all 3 are in tight.

Re. the shielding; those shields are only connected at one end, to provide a single path to dissipate any energy. Those are very low-voltage signals carried by those wires, so any outside interference (ignition, mostly) will screw up the signals.

[Larry Witherspoon]

Thank you JC I will recheck

Ssspoon

[turboleg]

Did you reset the ECU after replacing the plug?

[Matt Monson]

Who is this Larry Witherspoon guy? He's got a really old join date but I have never seen him post before?

Welcome back Larry. As mentioned, I would clear the ECU and see what happens...

[BXSS]

+1 on reset.

When my knock sensor was bad I got 5 codes ( knock sensor, MAF, Stater signal, .....).
I plugged the new K-sensor in, reset the ECU & I had no more codes.

[Legacy777]

Who is this Larry Witherspoon guy? He's got a really old join date but I have never seen him post before?

He's a nooob