Dear BB forum:

This is a post of an issue that I have observed with my '02 V70 (235 Kmiles), which I have posted recently. But I wanted to give an update, after doing some additional research online. As mentioned, my mechanic replaced the car's steering rack, and noticed that it would stall when accelerating (after he was done with the repair). Apparently he did run the battery down (left the key in pos. 2), and had to recharge it ... which may have caused the ECU to loose volatile memory data. Assuming that this is the case, does anybody know what the official procedure is for the ECU to relearn that data? Also, the check engine light is/has been on with a tripped O2 sensor code. Will this code need to be cleared (i.e., O2 sensor replaced), before ECU relearn procedure can be performed?

Thanks.

Bernie

You might want to look and see if the O2 wiring was disturbed/damaged during the steering rack surgery. If they lowered the engine along with the subframe certain wiring could have been stretched beyond limit. What's the code (to determine upstream or downstream O2 sensor)?
--
Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)

Hi Chris, the front O2 sensor code was already there before I dropped the car off for the steering rack replacement.

Thanks.

Bernie

Unplug the negative wire to the battery. Push on the brake pedal or turn the key switch to pos II and back to zero. Plug the negative wire back in.

This will erase all codes.
--
Keeping it running is better than buying new

Hi Klaus - that's good to know. What year models does the code reset trick work for? Also, if the O2 sensor was already bad going into the shop for the steering repair, wouldn't the code likely come right back immediately after erasing it?

BR

Bernie

It will probably come back on pretty quickly if it is an O2 sensor code.