Hi All!

Wife.gov drives a 2005 S80, about 162 K miles. Car has been running well, then last Saturday she got a "Check Engine" light. Took it to our FLAPS today, but they could get their OBD II reader to work--said it looked like no power at the connector. Checked fuse 9 (5A, supposed to control the OBD) and it was good.

I did poll the various modules to see if they had set DTCs (using "READ" and "REAR FOG LIGHT" buttons). Car shows DTCs for the ECM, CEM, DDM, PDM, CCM, and REM, but couldn't read the actual codes.

Not sure of next step...but have appointment at dealer for WED AM to see if they can figure it out.

FWIW, the car still runs great, with no indication of a problem other than the "Check Engine" light.

Appreciate any insights/BTDTs.

Thanks in advance,

Steve A-

Ps. I did recheck the gas cap--it was on straight, tight, and the o-ring looked good.

Thanks for all of the inputs and suggestions. reseating connectors on the CEM got power and cleared the bogus DTCs (communication with L/R door modules, etc., etc.). The remaining DTC, ECM 120D, was traced positive crankcase pressure caused by a clogged crankcase vent system. Replaced the oil trap and related hoses and it's now all good.

BTW, when I picked up the parts at the dealer I mentioned that I was a little surprised to see this problem at 164K miles since I change the oil and filter more often than the Volvo-recommended interval...mechanic said that they sometimes see this problem at < 70K, even when following the recommended interval (oil and filter change at 7.5K). Now hoping to get at least another 100K ;)

Thanks again!

Steve A-

I expect this condition to be 'normal' at 160K+ miles, regardless of oil type and oil change frequency. It also is determined by how often the engine oil gets hot enough to 'burn off' contaminates. A 20 minute ride to work, with the gear selector in "D", will not get the engine oil and the PCV hot enough to clean itself.

Using synthetic oils will extend the life of the PCV system, at least double the life of engines subjected to conventional oil.

My wife had an Audi A4 with the 6 cylinder engine. It had an oil temp gauge, and after getting home from work, the gauge was still on the cold side, a 30 minute commute. It had a clogged PCV at 90K miles.
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Keeping it running is better than buying new

Thanks for the good advice. I'm definitely a member of the "Keeping it running..." school. I'll be working on our two 240s this week.

Thanks again

I didn't do the second PCV service soon enough on my wife's 2.5T S80 (206,000 miles). That led to a huge engine oil leak and a new-to-us S60 Inscription in the garage.
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Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (STILL not road worthy!)

Thanks, I'll look into getting one of those tools today. I should look at getting a scanner too.

When you getting ready to do the work drop me an Email at
humbertoflores63@hotmail.com

There are some do's/ dont's that you need to watch out.

If you taking to a mechanic you can disregard this message.

I am not sure about your S80 but recently fixed an S60 by removing and re-attaching the computers. It seems the pins get out of alignment when the car hits a pot holes. It is a real pain but keep it just for another option.

Try another scanner may be the one is not working properly.

+1 on reconnecting the ECM and TCM. We had that problem with our 2005 S80. Other than the $15 for the tool, it costs nothing to try.
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Current rides: 2018 Volvo S60 Inscription (What the heck do all these buttons do?), 2005 Volvo S80 2.5T (Soon to go bye-bye), 2003 Volvo V70 2.4NA (The family "truck"), 1973 Volvo 1800ES (STILL not road worthy!)