Two weeks ago my check engine light came on. Went to Auto Zone and they scanned (for free!) and got code P0140. The guy reset so the light would go out and told me if the light came back on in the next day or so to come back and he would scan again. I drove the car for two weeks, and no code. Yesterday the check engine light came on and I went by Auto Zone again - same code. Any idea what I might expect when I take to Volvo mechanic? I don't want any surprises!!

Rule308 is right on! But for future reference, use this web site:

http://www.actron.com/code_lookup.php

It will let you enter the "P" number and give you the one line explaination.

Klaus
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(V♂LV♂s 1975 164, 1995 854T, 1998 V70R)

I got my numbers mixed up in typing! Thanks for the responses - the correct code is P0410 - Secondary air injection system malfunction. Is this something I need to take in for checking? I've done some minor work on my car, but this isn't my area of expertise!

Deb

Just did this one on our 850. As Klaus says, the air pump is under the battery tray. It is connected to a round valve (SAS valve) up on the engine near the firewall by a hose. Due to a design flaw (Volvo engineers are good but apparently didn't realize water runs downhill) condensation in this line runs down and eventually fills the pump with water shorting it out. Mine must have had a pint in it. You can drill a small 1/8" hole in the bottom of the pump to drain it but it's probably shot. To check it, just unplug it from its relay (usually right beside it) and apply 12v to the blue wire. If the pump runs, your problem is elsewhere. May be the SAS valve, relay or the small selonoid located on the inside of the radiator shroud (has a purple and white vacuum line running to it plus an electrical connector. Replacing any of the components is fairly easy, well within the av erage DIYer.

New pumps are expensive (~$300. at Groton, probably $450.ish at dealer. I lucked out an found a new one on ebay for $150. but that was pure luck. I've seen several used ones there since.

LOL That code is not a critical problem. It means that the air pump for the cold start condition is not working. That air pump is to reduce emissions while the engine is cold and the gas/fuel ratio is rich. If you live in a state that checks emissions, you will need to get it fixed before testing.

The air pump is under the battery tray, but it could also be the relay that is above/behind the radiator. Volvospeed has a good write up:

http://www.volvospeed.com/Repair/airpump1.php

Klaus
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(V♂LV♂s 1975 164, 1995 854T, 1998 V70R)

Here is the definition of that code. "O2 Sensor CKT No Activity (Bank 1 Sensor 2)" What this means in laymans terms is that the rear O2 sensor is dead in your car. '96 and later vehicles are OBD II equiped, this means that they monitor certain components in your car and have readiness tests or monitors that they must pass in order to be fault free. Once the readiness tests are past and the monitors are said to be up the control unit monitors the systems and components that it is supposed to. If no faults are found then it will not post any codes and the lights stay off, in the event that one of the components fail or it does not pass one of the routine tests run by the ecu then a code is posted and the light comes on. In your case it has detected that the rear 02 sensor is not operating. The rear 02 will usually do one of 3 things, usually, it will either read correctly at around 4-500 millivolts, vary between .1-.9 volts (bad cat) or it will show no activity and be dead in the water, bad sensor. If you brought the car into my shop I would charge you and hour labor to pull the code and check the car out and half an hour labor to replace the sensor. 1.5 hours labor to inspect, diagnose, and replace the rear 02 sensor is a fair price. Volvo list on that part is 236.00 and another 25.00 for an adapter cable that they recommend. You can get the parts cheaper and do the work yourself but you will also have to provide your own warranty and actually get in there and do it yourself. Just a word to the wise, the connector on that sensor is kind of a pain in the ass and you will probably want to have an 02 sensor wrench to bust it loose.

Mark