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Persistent Engine Performance Issue- even after major fixes

Help, Advice, Owners' Discussion and DIY Tutorials on the Volvo S80 model. Sometimes called an "executive car", the S80 was and continues to be Volvo's top-of-the-line passenger car.
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andeus
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Persistent Engine Performance Issue- even after major fixes

Post by andeus » Sat Feb 01, 2020 6:00 pm

Long time no see, MVS squad.
Got a new problem on my hands that I can't make heads or tails of even after research and fixes.

Car is a 2004 S80, 2.5L Turbo, FWD.

This week began with a seemingly innocuous flag.
I would start my car from a cold start, and get the dreaded message saying Reduced Engine Perfomance.
Turning off the car and starting it again would make it go away.
I thought maybe it was the battery, since after checking, the date code for the battery said 10/2013- 7 years old. (Battery should be coming tomorrow, by the way)

Then, from Monday to Tuesday, the same message would pop up on a cold start, but only go away if I "cleared" the code with my little OBD2 reader.
I put clear in quotation marks because the CEL never turned on - still doesn't.
But when I attach the code reader, it will say "Codes: 0"
Pressing 'Read' would sometimes yield me P2127 code or other times, no codes at all.
Pressing 'Clear' would clear the code, even with no DTC code read.
The Reduced Engine Performance message would go away, and the S80 would run fine.

P2127 = Throttle/Pedal Position Sensor/Switch 'E' Circuit Low, and my research on various Volvo forums indicated that replacing the PPS (Accelerator Assembly) would fix the issue.
However, since my previous S80 I owned had a similar issue that was fixed via replacing the Throttle Body, I ordered both parts, #30683516 and 30711554 respectively.

But it got worse from Wednesday to Friday.
The Reduced Engine Perfomance message would pop up 100% upon starting the vehicle, and during driving at random intervals. I would have to pull over, clear the code, and continue on my way.
I read about the onboard DTC trick with the READ and Fog Light buttons, so I took pictures to take note of the DTC SET messages, seen here.
On Friday evening, it got to the point where no matter how many times I tried clearing the code, the Reduced Engine Perfomance message would persist.
Still no CEL, but stuck in limp mode, so I limped all the way home.

Both parts arrived today, Feb. 1st.
Installed both without issue- the throttle body was a pain, but I did it.
I took pictures of its super crusty condition to compare, shown here.
After finishing the install, I turned the key to Pos 2, as specified on this forum.
After 25 secs, there were about 3 clicks, and nothing.
Last time, on my previous 04 S80, I had a throttle body replaced with a new one by a professional, who stated there was no programming required.
Some other forums agree, some do not.

Started the S80 after cleaning up, and Reduced Engine Perfomance was there to welcome me.
No CEL, unable to clear / persistent, and Codes: 0 but P2127 DTC.
I took pics of the onboard DTC read out here, if it's any help.

What's really going on?
Which part(s) were/are the culprit? Would replacing the battery (should be tomorrow) help?
Does the code need to be cleared by a professional with VIDA or something?
Am I missing something else?

Any input on this would be appreciated...
Currently cruising (or fixing) my 2nd 2004 Volvo S80 2.5L Turbo.

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Re: Persistent Engine Performance Issue- even after major fixes

Post by jimmy57 » Sat Feb 01, 2020 9:07 pm

Before you do anything else turn key to Pos II and wait over 45 seconds for the throttle sensor calibration to happen. You will hear throttle cycle twice. The ecm closes it fully to check min voltages and then opens it fully and checks max voltages (truly it is min voltage closed on one and max closed on other and when throttle goes open the signals invert.)
If still an issue then the ECM needs to be removed and terminal corrosion checked there and in the throttle connector.
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andeus

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andeus
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Re: Persistent Engine Performance Issue- even after major fixes

Post by andeus » Sat Feb 01, 2020 10:59 pm

jimmy57 wrote: ↑
Sat Feb 01, 2020 9:07 pm
turn key to Pos II and wait over 45 seconds for the throttle sensor calibration to happen. You will hear throttle cycle twice.
Inserted key, turned to Pos 2- engine bay clicked and whirred a few times (the calibration, I assume).
Turned on car thereafter, and the Reduced Engine Performance message came up immediately, same symptoms as before.
I can "clear" the code while in Pos 2, but it remains persistent when the car is on.

How do I remove the ECU?
Does this mean the ECU has to be replaced?
And if so, does it have to be professionally programmed?
Currently cruising (or fixing) my 2nd 2004 Volvo S80 2.5L Turbo.

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Re: Persistent Engine Performance Issue- even after major fixes

Post by andeus » Sun Feb 02, 2020 1:07 pm

jimmy57 wrote: ↑
Sat Feb 01, 2020 9:07 pm
If still an issue then the ECM needs to be removed and terminal corrosion checked there and in the throttle connector.
Using a tutorial, I disconnected the battery's negative cable, switched the car to Pos 2, and pressed the brake.
I read this would discharge residual power.

After waiting a while, I used a video to remove the ECM units.
They look near flawless. Pictures here.

Where do I go from here?
As of posting this reply, ECMs are disconnected and car remains disconnected from the battery in pos 2.
Currently cruising (or fixing) my 2nd 2004 Volvo S80 2.5L Turbo.

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Re: Persistent Engine Performance Issue- even after major fixes

Post by aussieviking » Mon Feb 03, 2020 6:40 pm

Unfortunately from what I've read and heard about these cars is that some of the aftermarket code readers cannot show the full extent of what codes are actually stored. You may need to get someone that has a copy of DICE to read the codes to fully understand what is being logged.

It might even be worth getting a cheap copy yourself and set it up on an old laptop, it's not too hard.. just don't change the configuration of the laptop once it's installed and running.

There is a wealth of information in the software itself once a code is logged, it will give you the symptoms and suggested fixes etc.

The one time I received a reduced engine performance code was when I blew one of the intercooler hoses off so it was trying to run NA.. but if you never had them off I wouldn't suggest that being the issue.

It does sound like it could be a throttle signal or pedal signal issue even though you've tried a replacement. Then again it could be one of the critical sensors it's not getting a signal from so it doesn't want to run at all.

What happens if you try unplugging the MAF after having the battery disconnected, whilst trying to start it with the OE throttle body?
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Re: Persistent Engine Performance Issue- even after major fixes

Post by andeus » Mon Feb 10, 2020 4:44 pm

aussieviking wrote: ↑
Mon Feb 03, 2020 6:40 pm
It might even be worth getting a cheap copy yourself and set it up on an old laptop, it's not too hard.. just don't change the configuration of the laptop once it's installed and running.
I don't have that much money as is- I'm a college student; these replacement parts alone set me back quite a bit.
I know VIDA, let alone a laptop, is super expensive... :(
aussieviking wrote: ↑
Mon Feb 03, 2020 6:40 pm
What happens if you try unplugging the MAF after having the battery disconnected, whilst trying to start it with the OE throttle body?
Just tried that now- the car starts fine as per usual, even without the MAF sensor plugged in.
Can't replace the new throttle body with the old one- although the swap is straightforward it takes painfully long to do...
Currently cruising (or fixing) my 2nd 2004 Volvo S80 2.5L Turbo.

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Re: Persistent Engine Performance Issue- even after major fixes

Post by SuperHerman » Mon Feb 10, 2020 9:17 pm

With the onboard diagnostic - are all reports coming back with "set" (the pictures show only some of them - what of the others?) I am looking for ETM - which is not shown in photos. Also you want them to read "ready"

http://mr-fix.info/volvo-hidden-menu-dtc-check/

As I understand it the Bosch throttle body is plug and play.

Put in the new battery, make sure it is fully charged and see if you get the "ready" readings.
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Re: Persistent Engine Performance Issue- even after major fixes

Post by andeus » Wed Feb 12, 2020 7:17 pm

SuperHerman wrote: ↑
Mon Feb 10, 2020 9:17 pm
With the onboard diagnostic - are all reports coming back with "set" (the pictures show only some of them - what of the others?) I am looking for ETM - which is not shown in photos. Also you want them to read "ready"

http://mr-fix.info/volvo-hidden-menu-dtc-check/

As I understand it the Bosch throttle body is plug and play.

Put in the new battery, make sure it is fully charged and see if you get the "ready" readings.
Thanks for replying!
I took a video, just to make it easier:


I had a friend swing by with VIDA, and he said the ECM returned the ETM adaptation as "OK".
So the throttle body is fine...?

We did a test with the Accel. Pedal sensor.
Depressed read 0.4V,
Pressed it read 4.5V or something

Where do I go from here?
Currently cruising (or fixing) my 2nd 2004 Volvo S80 2.5L Turbo.

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Re: Persistent Engine Performance Issue- even after major fixes

Post by andeus » Thu Feb 13, 2020 6:36 am

UPDATE: Got PDFs of the DTC readout and Car Info:here
Currently cruising (or fixing) my 2nd 2004 Volvo S80 2.5L Turbo.

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Re: Persistent Engine Performance Issue- even after major fixes

Post by SuperHerman » Thu Feb 20, 2020 12:39 am

Watching the video - the diagnostic should read "ready" for each module that is being addressed by the computer. "Set" is not a reading one wants. Your numbers on the pedal sound correct per your attachments. I think your problem is pedal related so you can ignore the other errors on the print out you posted.

My sister had a similar issue with her XC70, same engine, and the culprit was a failed relay. She started by replacing the pedal with no positive result. So I would focus else where first - the relay. I am looking at what you linked but cannot find the relay. She used VIDA and the flow chart it included to find the problem.

Maybe you get lucky and RickHaleParker helps out. What you need to do to eliminate the relay, is figure out which figure in the schematic is the throttle pedal - then follow the wiring until you find the relay it ties into. I have tried with no luck for the last 20 minutes. Other option is to ask your friend if he can use VIDA and follow the required sequence to help you. My sister made it sound like the software, going through the fault trace, pointed her to the specific part.

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