2006 S60R Reduced Engine Performance Topic is solved

[jcgirton]

Last week I replaced the thermostat housing in my car - I don’t know if maybe I disturbed something else in there but everything was fine until today and I've driven well over 100 miles at this point.

I got in my car this morning and it started right up but said “Reduced Engine Performance.” and was running kind of rough. I turned it off, back on, same thing.

Disconnected the battery for a few, turned it back on, everything is perfect, no error message. Backed up the driveway and thought for a second - I have an hour drive to work, let me make sure it’s not going to act up again. Turned it off, back on, error message and running rough. Drove around the neighborhood and was clearly in lump home mode with no pickup.

At some point the error message “Engine System Service Required” came up as well but this later went away after disconnecting the battery.

I scrolled through the set DTCs but haven’t been to auto zone to have the actual codes pulled but almost everything was set.

BCM
SAS
ECM
DEM
AUM
CEM
DDM
CCM
SUM - this has probably been set for awhile
PDM
PSM
REM
UEM

So I pull back up and disconnect the battery again for awhile, this time I pulled it out and touched the negative / positive cables together.

I put the battery back in, this time before starting it up, I turned the ignition to place 2 and just let it sit for a second. Initially everything is fine, then before even trying to start the car I get the “Reduced Engine Performance” notice and the same DTCs are set.

I start it, starts right up, no hesitation, same thing happens of course - running a little rough.

It seems like from googling it could be a variety of issues - does the fact that the message pops up before you even start the car point in any specific direction?

[June]

My 2004 has a temperature sensor on the thermostat housing. I understand this should be replaced every time as it can cause havoc of some kind. Is it plugged in tight? Just a thought. June

[jcgirton]

Yes it came with a new temperature sensor on the new thermostat housing, it registered temperature this morning, you could see the car was warming up. I just went out and disconnected and reconnected the temperature sensor, same thing happens.

[chrism]

The fact that you turned the ignition on to Pos II and got an error message before the engine was even running may be somewhat telling.....

May be time to re-seat the ECM and TCM. (That's my standard first try fix for anything except a flat tire.)

[abscate]

The error codes latch so the fact that the REP message is coming on is just your car remembering that it isnt right.

Dont touch the ECM and TCM. Disconnecting the battery or ECM is just clearing the codes, not working the problem.

What is your service history on:

Coils 120k life
Plugs 30k life
PTC cleaning every 50k
Oil changes 3-7.5k depending on usage

and how many miles now?

[jcgirton]

167k I bought it last February, so only have had it a year - I'm sure the plugs are due, I don't know much about the history but what little I do have shows regular oil changes and them taking it to Volvo and I changed the oil not too long ago with a full synthetic

I went to NAPA and used their obd2 tool - the only code that pulled up was P2111 TAC System Stuck Open - I cleared it, shut the car off, turned the ignition back on, code came right back up - which seems to make sense since the rpms are bouncing for the first little bit the car starts up like its trying to figure out what position the throttle is in

Of course googling it.. people say they've cleaned it, some people said they bought a new one and it fixed it, other people said they bought a new one and it didn't do anything and then they had to re-seat the ECM and it fixed it

My car was totally fine yesterday, sat over night, then this morning there's an issue - which one seems most likely as a solution?

[abscate]

Try the 'throttle body reboot' as its free.

Turn the key to POS II , but don't start it. Sing the Jeopardy theme. Twice. Second time backwards.

Then give it a try on the road.

To go further, you need VIDA/DICE to tell you what is out of sorts. The guess strategy will take you to about 10 different things, each costing $100 or more to 'guess', so thats a bad bet.

[jcgirton]

Well that fixed it! For some reason I thought it only did that after you unplugged it the throttle body and plugged it back in... no idea why I thought that either - thank you so much! Think this is a one off or a sign of impending doom?

[mrbrian200]

Connector might not have been seated properly - even if you didn't unplug the throttle body during the previous service if you bumped the connector/wire while working in the area they are known to be 'touchy' and lose connections to the throttle body on some vehicles. Volvo sells a replacement pigtail for these to address the issue. xemodex also sells this pigtail and encourages people to try replacing the pigtail before sending any of their custom made bosch type throttle bodies back for a warranty claim.

And yes, it might be a sign of impending doom.. Disconnecting the battery for a longer period cleared the adaption table the ECU had on store for the throttle body. It's not my experience that such problems will occur with a known good throttle body just because you forgot to run the self calibration procedure after having the battery disconnected. This implies that the ECU has trouble controlling/adapting the throttle body without first running a calibration sweep whereas in my experience with a good throttle body the ECU is able to cope.


If for some reason the problem recurs my initial thought was--
Sat overnight, next morning seemingly every module is in error. Inspect for rodent damage in the wiring under the hood, behind the bumper and under the windscreen cowl. They get the munchies for vehicle wiring sometimes.

[abscate]

Dont let MrBrian get you down...it is definitely fixed until it happens again.

Dont get me down....ELO....