mike Wrote:AFR sensors don't go up to 12 volts on the signal wire. You probably have the heater wire. The heater on wideband sensors doesn't get a constant 12 volts. The ECU modulates the heater power voltage to maintain a constant temperature at the sensing elements.
You haven't got the correct wire identified yet, and need to find it. When you find it it will be in either the 3.3 volts or 2.7 volts range. If you have an AFR sensor there will be 2 wires in the same range, and one of them will fluctuate slightly. That's the signal wire.
I'm fairly sure I hooked up to the right wire. It is not my first time tapping into electrical or tracing wires. But please read below and hopefully you will point out a fixable solution to the problem.
There are 4 wires on each sensor
2 are spliced together by the factory immed. after the sensor plug and are grounds
1 has a steady 13 volts
1 has a fluctuating voltage of 4-8 volts. Normally about 6 + - when at idle with the ac off.
I tapped into the fluctuating wire which I determined to be the signal wire.
This must be the wire and it does have a fluctuating 4-8 volts according to the voltmeter.
Any suggestions? Sorry if this gets long, but great questions and will help big time if you can answer them. thanks.
Is it a different type of sensor than an A/F?
Is it an A/F with higher than normal voltage readings? Even though I replaced the sensors with new ones and came to the same results.
Although I used 5 different voltmeters, could the reading be innacurate?
What wattage can the EFIE handle? At open loop it is 13V and undetermined amperes. But I know with A/F sensors that the amps are greater the farther from 3.3 volts it goes. I will test for the amps soon.
Normally - would this EFIE be hooked up in reverse to subtract voltage?
Lower volts means richer to the ECU which would make the ECU lean out the Air fuel ratio
theory: Possibly it is not an A/F sensor? Could there be other types of sensors made in 2005?
Possibly it is just reading rich so the volts are higher than normal?
Possibly the voltage is not being read accurately do to a factor not considered - like connecting to the chassis ground instead of completing the circuit through the ECU? Or another unknown.
I would love the problem to be because I used the wrong wire, but is probably something else - hopefully with a solution,
I'll take any ideas and theories at this point. Thanks!