What happens if you reverse the O2 sensor wires? (4-wire sensor)
10-29-2010 | 02:17 AM
#1
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What happens if you reverse the O2 sensor wires? (4-wire sensor)
My brother's VW Corrado check engine light is on with the code for no O2 sensor signal... I checked it with a multimeter and it's working fine. The sensor is new anyway, but I had to splice the wires in myself. I may have gotten them backwards (not the heater wires, the 2 wires for the signal).
So what happens if the signals wires are reversed?
TIA. Volkswagen forums are shameful for getting technical answers but I figure this general question will make a good chew for rennlist.
So what happens if the signals wires are reversed?
TIA. Volkswagen forums are shameful for getting technical answers but I figure this general question will make a good chew for rennlist.
10-29-2010 | 02:27 AM
#2
Lazer Beam Shooter
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From: Taco island
Just switch them back. It shouldnt hurt it. The VW sensors should have 2 gray wires (heater circuit) and a white, black wire. One is the signal, and the other is the signal ground.
10-30-2010 | 06:12 AM
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Rock, I think you're right. I'm pretty sure I got the heater wires right (i.e. not spliced to a ECU wire), I wish the wiring diagram was more helpful.
Manny, how can you say nothing should happen, then say a volt should kill the ECU?!? The O2 sensor is putting out 0.9V at times! Corrado ECUs aren't cheap like typical vw parts.
Manny, how can you say nothing should happen, then say a volt should kill the ECU?!? The O2 sensor is putting out 0.9V at times! Corrado ECUs aren't cheap like typical vw parts.
10-30-2010 | 08:08 AM
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Lazer Beam Shooter
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From: Taco island
Rock, I think you're right. I'm pretty sure I got the heater wires right (i.e. not spliced to a ECU wire), I wish the wiring diagram was more helpful.
Manny, how can you say nothing should happen, then say a volt should kill the ECU?!? The O2 sensor is putting out 0.9V at times! Corrado ECUs aren't cheap like typical vw parts.
Manny, how can you say nothing should happen, then say a volt should kill the ECU?!? The O2 sensor is putting out 0.9V at times! Corrado ECUs aren't cheap like typical vw parts.
Id try and install it right then reset the CEL. Sometimes when you install the oxygen sensor, it might take some driving to clear it. So if it doesnt go back off immediately dont freak out. Actually even with a bad sensor, it takes some time for the ECU to detect abnormal readings so it takes a little bit of time for it to come on anyway.
10-31-2010 | 12:20 AM
#6
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From: Bedford PA
well on the obd2 cars that are drive by wire, the rear o2 sensor circuit is tied in to the drive by wire and if those wires touch (like from incorrect installation/wiring or car being lowered and rubbing asphalt) it WILL fry the dme......damn VWs....
10-31-2010 | 01:47 AM
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Yikes, luckily this is obd1.
When we clear the code, it does take a little while for it to come back. Hopefully reversing the wires solves it, I'll try tomorrow. Thanks all for the help.
When we clear the code, it does take a little while for it to come back. Hopefully reversing the wires solves it, I'll try tomorrow. Thanks all for the help.
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11-01-2010 | 12:39 AM
#9
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Ah, that makes sense!
My brother found what we think is the main problem - there was a break in one of the wires from the sensor to the ECU. He sealed a leak with silicone so once that cures by tomorrow we'll test drive it and see if the code stays off.
My brother found what we think is the main problem - there was a break in one of the wires from the sensor to the ECU. He sealed a leak with silicone so once that cures by tomorrow we'll test drive it and see if the code stays off.
