my 95 850 had a check eng. lite, indicating front oxygen sensor problem. i replaced the sensor, and have tried to reset the CEL with the directions i have, but had no success, can anyone help me! this is with the under hood obd-1 icant reset the lite to see if the oxygen sensor cured it. thanks bobd

Hi bobd hope this helps

Note that the fault codes cannot be deleted untill all of them have been displayed at least once and the first one is displayed again. With the flylead still inserted in socket 2 .....(or whatever socket you are trying to clear) of module A or B. Switch on the ignition, press the test button and hold it down for approx 5 seconds the LED will light. When the led lights and before it goes out, press and hold the test button down for a further 5 seconds then release it, the led will go out, switch off the ignition. You than can check that all the fault codes have been deleted by swithcing the ignition on again and pressing the test buttion for 1 second code 1-1-1 should appear. If a code other than 1-1-1 apprear, record the code then repeat the deleting procdure.

Ketchb

Turn the ignition to the on position, (all indicator lights will be lit opn the instrument panel)Go to engine comparment, get the wire at the side of the obd box and connect it to #2 on left side. Press the button for about one second. Led will blink aseries of three digits. Write it down. Repeat the process until the first series of digits is repeated. Then press the button again for seven seconds. After that the led will light and will stay on. Press the button again for seven seconds. You wll hear a funny noise comming from the engine (a low sucking sound). You are done. That´s it

Good luck
Luis

With key on engine off:

1)insert cable into socket A2
2)depress button for 1 second
3)read code, example: flash,flash-pause-flash-pause-flash,flash=212
4)repeat this until the first code is read out a second time
5)hold button down for 5 seconds and release
6)light stays out for 5 seconds and then comes on again
7)push button down as soon as it lights and hold down for another 5 seconds and then release it
8)wait a couple of seconds and then push it down for 1 second to check for the pressence of any codes. If the reset took it will flash a 111 or all clear code.

You can do this while it is running the only difference is that when it clears the code you will get a huge idle dip and/or the engine will stall entirely. It has been my experience that more of them stall than anything else. I usually do it with the engine running as the idle dip is your indicator that the code has been cleared and the adaptive reset. The above method is right out of the book and exactly how they teach it in Volvo school, most guys I know tend to go a little long on their count and will usually count off 8-9 seconds which usually works fine but from time to time you will get a pain in the ass car that will not reset unless you do it right by the book and actually watch the second hand sweep on the shop clock and count of exactly 5 seconds, weird huh?


Mark