Wankel7

I am trying to track down my Code 17 (Feedback error to do with the o2 sensor). on my '91 TII. I did a continuity test on the sensor wire. I used a volt meter and had one probe in the ECU terminal for the 02 sensor and the other at the end of the 02 sensor wire in the engine bay. Upon doing this I had perfect contunity. However, I had perfect continuity on many other pins in the ECU wiring harness. I don't remember what other pins.

This concerns me. I thought the wire that goes from the 02 sensor DIRECTLY to the ECU. Why am I getting continuity on other wires? Does this mean there is a short somewhere in my wiring harness? I need some help on this one.

Can somebody do a conituity check and see if they get continuity on other pins?

James

HAILERS

Got me. Do you have the plug at the ecu disconnected when you are reading continuity? Are you real sure that you are not on the shield of the o2 sensor? If you are you are reading to ground.You probably are not doing that, but what if? With the ecu connected and the o2 connected, have you started the engine and run it at say 2000 rpm and tried to see what the reading on the meter is? Read somewhere that you should only use a digital meter if you try this. Reading should be jumping around between say .1 to .9volts. Just some thoughts.Edit....You might be interested in an article at the url http://www.autometer.com go to HIGHPERFORMANCE on the opening page then click on the left side of the page TECHTIPS/FAQ and you will find an interesting aritcle on o2 sensors.

Wankel7

Yeah, the plug was disconnected when I was doing the testing. I took my digital voltmeter to that wire when the car was running and got nothing (No voltage at the ecu). But I then disconnected the 02 sensor and got the voltage. My guess is I have a broken wire in the harness and that is doing one of two things. (Or both...why limit myself). IT is grounding out or touching anouther broken wire.

I am going to run a new wire from the 02 sensor straight to the ecu. That should not cause problems. Any ideas?

James

HAILERS

No real ideas. I go with stringing a new wire. By the way, if both ends of the wire are disconnected, can you, from the center conductor go to a chassis ground and get continuity? Kind of sounds like a dead short in the wire somewhere. Have fun.

bobr

If this helps, the wire on mine was broken inside the insulation where the connector to the O2 sensor comes off the engine harness. It seems like that potting compound inside the connector lets the wire bend at 90 degrees and makes it subject to breaking. All I did was crimp a new terminal on and reconnect to the O2 sensor and all was well.

Wankel7

Well I ran that wire straight to the ecu. And for once I beleive my ecu is getting an 02 reading. The Halmeter Air/Fuel is dancing between lean and rich like crazy at idle...it never did that before.

Going to test drive it tomorrow at daybreak. Crossing fingers!

JAmes

Suparslinc

This might not help, but a while back I was getting an 02 sensor code on my '90 GXL. After wiggling the wire around a little bit, at the plug and also where it sits on that little bracket, the code stopped popping up. Obviosly you've gone alot further than this in trying to diagnose the problem, but I thought I'd remind to check the simple things

RotaryMan88

Hey James, hadn't hear from you in a while. I thought you got everything working fine and went home to Danville, lol. Sorry about that wire problem...just so you know, my friends Lean/Rich meter jumps from Lean to Rich at idle too, only when he gets on the gas does it go one way or the other....

Wankel7

Well, I believe I fixed my code 17. I think it was simply a broken wire in the harness somewhere. So I ran a new wire to the ECU from the 02 sensor. Things appear to be working now. No more check engine light.

No i need to fix my heater core leak. Yey

James

HAILERS

Heater core? Egad! The one that keeps you warm in the winter? Hope I never, never have to do that. Hate with a passion any underdash work. Have fun.