FAQ's - GOT QUESTIONS? SEARCH HERE FIRST BEFORE POSTING!

[Forkster]

There is a genuine need for a FAQ thread here in our segment, from what tires to get, questions about vehicle functions, transmissions, what to change, ETM, and alike. We'll strive to have the best answers possible based on the information we know at the time. Try not to take this FAQ as the end-all-be-all but a work in progress. Some of our answers will not be perfect, but if you come across anything that can help us build a better FAQ, please let me know!

This FAQ is for all questions relating to the 2001-2007 Volvo XC70 only. Post the question AND the answer. I will have SPAM deleted - so please stick to the topic - post the question and the answer OR the forum posting that answers it.

To add a FAQ entry: Post the question in the subject line and answer it below with references if possible.
[thumbup]

[Forkster]

215/65R16 is the standard OEM size but you can get 17" or 18" rims from Volvo at time of purchase at varying tire sizes. You can up-size on the original rim to 235/60R16 as it is within 1% of the original size.

If you wish to put larger rims on from a third party, you'll need to ensure it fits well.

1010Tires has a great tire size calculator here: http://www.1010tires.com/TireSizeCalculator.asp

Put in the OEM size and start playing with tire size!

[Forkster]

LOTS OF OPINONS!

http://www.volvoxc.com/forums/showthread.php?t=2389&highlight=tires%3F
http://www.volvoxc.com/forums/showthread.php?t=2150&highlight=tires%3F
http://www.volvoxc.com/forums/showthread.php?t=7292&highlight=Tires
http://www.volvoxc.com/forums/showthread.php?t=10740&highlight=Tires
http://www.volvoxc.com/forums/showthread.php?t=1985&highlight=Tires
http://www.volvoxc.com/forums/showthread.php?t=8023&highlight=tires
http://www.volvoxc.com/forums/showthread.php?t=80&highlight=tires

Nokian WR's are a favourite around here as the ideal 'all-season'.

[Forkster]

http://www.volvoxc.com/forums/showthread.php?t=10814

[Forkster]

http://www.volvoxc.com/forums/showthread.php?t=10772&highlight=snow+tires

http://www.volvoxc.com/forums/showthread.php?t=9160&highlight=snow+tires

http://www.volvoxc.com/forums/showthread.php?t=8023&highlight=snow+tires

Just to clarify: there is a HUGE difference between winter tires and snow tires - its a bit of a misnomer. Snow tires are also considered ALL-SEASONS. They are NOT winter tires. If you have 'winter' tires, especially here in Canada, they require the following symbol on their side:
http://www.oregon.gov/ODOT/COMM/images/snow_tire_symbol.gif

Outside North America? Check with your governments transportation divisions for the correct symbol. This symbol is found on all North American and European Winter tires. This symbol is also an international standard for Winter tires.

[yournamehere]

Boost Control Valve- issues should be in the sticky!

[Forkster]

http://www.volvoxc.com/forums/showthread.php?t=9888
and
http://www.volvoxc.com/forums/showthread.php?t=9748

[Forkster]

You can but not too much. If you want a real performance wagon, purchase a V70R. :)

Some idea's here on what you can mod.

http://www.volvoxc.com/forums/showthread.php?t=8265

Reddiz's stuff: http://www.volvoxc.com/forums/showthread.php?t=8207

VADIS Upgrades: http://www.volvoxc.com/forums/showthread.php?t=6320&highlight=mods

Customer Programmable Settings:
http://volvoxc.com/resources/how-to/pdf/programmable_customer_parameters.pdf

[RedXC]

Just heard from Volvo that before doing any transmission replacement. There is a step to test the ATF fluid if it any trace of chemicals from coolant was in the gearbox, which a Volvo engineer found the cause of transmission failures. And they require you to replace the radiator if the tests was found positive with the trans replacement.

[RedXC]

Knocking noise over bumps.

Mainly these parts:
-Spring Seats
-Sway Bar Endlinks
-Worn/Defective strut assembly
-Worn front control arm bushings

[Forkster]

You bet.

All kinds of great info on where to buy, and even how to install. Late model of the this generation may require a VADIS reprogram (05/06/07 - I think).

http://www.volvoxc.com/forums/showthread.php?t=10484

[Forkster]

On-line of course, and it's FREE - if you own a North American Volvo model - we're checking on other regions.

MY01 - http://new.volvocars.com/ownersdocs/2001/2001_XC/01xc_00.htm
MY02 - http://new.volvocars.com/ownersdocs/2002/2002_XC/02xc_00.htm
MY03 - http://apps.volvocars.us/ownersdocs/2003/2003_XC70/03xc70_00.htm
MY04 - http://apps.volvocars.us/ownersdocs/2004/2004_XC70/04xc70_00.htm
MY05 - http://apps.volvocars.us/ownersdocs/2005/2005_XC70/05xc70_00.htm
MY06 - http://apps.volvocars.us/ownersdocs/2006/2006_XC70/06xc70_00.htm
MY07 - http://apps.volvocars.us/ownersdocs/2007/2007_XC70/07xc70_00.htm



MYXX - Manufacture Year + last two year digits

[Forkster]

Lots.

Maintenance charts
Owner's Manuals
Vehicle Identification Numbers (VIN)
Vehicle Identification Codes (VIC)
Vehicle specifications
Warranty booklets
Press releasesWhere? Here: http://new.volvocars.com/loyalty_v2/ol_01_t7.asp

Note this is the VOLVO USA site and the information you are reading is for North American spec Volvo's, NOT European. We are checking on a Euro version of this site and will update if we have the information. You could register here:http://www.volvocars.us/tools/OwnersInfo/ for complete/regular access.

I've also attached a sample maintenance chart for the 2004 XC70.

[Forkster]

From JRL's posting...

If you own a recently new Volvo XC70, there is a small boot that comes of the DEM that can (and does) either get dislodged or clogged. Many times my service manager says these just fall off, or get clogged with road crap and give a false reading that the AWD is overheating and shuts it down.
Snow can be a leading cause of this. More details here how to resolve it: http://www.volvoxc.com/forums/showthread.php?t=10863

[Forkster]

http://www.volvoxc.com/forums/showthread.php?t=10866

130MPH - give or take a few.

[Forkster]

NO.
http://www.volvoxc.com/forums/showthread.php?t=10852


What about those Tornado fuel savers?
NO.
http://www.volvoxc.com/forums/showthread.php?t=7280

[Forkster]

You bet. HERE. (http://www.volvoxc.com/forums/showthread.php?t=10978) :)

[Forkster]

http://www.volvoxc.com/forums/showthread.php?t=11102

[Forkster]

NO. And if they try to upsell you on one, they're selling snake oil. So, just to confirm, THERE ARE NO FILTERS TO REPLACE. If they have one listed on the bill, ask them to remove it, or show you the one they pulled off. Then ask them to show you where it goes on. :)

http://www.volvoxc.com/forums/showthread.php?t=11094

There is an internal filter, but it's more of a screen that is designed to catch metal chunks. It can be replaced - IF YOU DO A TRANNY REPAIR - but not for a AT fluid flush/change.

[Forkster]

YES! The fluid is hyrdostatic - mean it absorbs moisture over time and turns brown. The fluid should be yellowish-clear colour. Use a brake pressuirsed bleeder (around $60) when doing the flush.

Details here: http://www.volvoxc.com/forums/showthread.php?t=10954
How to do it here (using a bleeder unit): http://www.volvoxc.com/resources/how-to/pdf/xc_brake_bleeding_guidelines.pdf

[Forkster]

Trailer with brakes: 1500kg (3300lbs)
Trailer without brakes: 500kg (1100lbs)

More info and discussion here: http://www.volvoxc.com/forums/showthread.php?t=11141
Here too: http://www.volvoxc.com/forums/showthread.php?t=7971&highlight=towing
Here: http://apps.volvocars.us/ownersdocs/2004/2004_XC70/04xc70_06b.htm#pg102
And here: http://www.volvoxc.com/forums/attachment.php?attachmentid=1019&d=1165048477

The how-to is located above this FAQ.

[Forkster]

All Winter tires are required to have this symbol on their sidewall:
http://www.ofoc.ca/images/severesnowflake.gif

Snow tires are also called All Season Mud + Snow. They are NOT winter tires and stop working effectively under 7 Celsius.

It is important to differentiate between a SNOW tire and a WINTER tire as they use completely different compounds in the rubber. Transport Canada and the NTSB recommend all-season/summer tires for warm temperatures for spring/summer driving and WINTER tires for fall/winter driving. Please note that all States/Provinces/County's/Countires have a spring-time date that WINTER tires must be removed as well as fall dates when you can put them on. Check your regional website for more information.

Update: there is a tire made by Nokian that are cross between winter and all-season tires. WR's are considered hybrid winter/all season tire. There are mixed views on their winter suitability and several members here on this forum can provide you with their personal experience/opinion if asked.

[Forkster]

No - but if you did it would of been easier to deal with.

Chances are it's your brake booster. Check here: http://www.volvoxc.com/forums/showthread.php?t=9307

It will need to be resolved shortly because you WILL eventually loose your brakes...at the most inopportune time.

[Forkster]

http://www.volvoxc.com/forums/showthread.php?t=11344

Nice step-by-step details on how you can disassemble the casing and check the functioning of the lock.

[Forkster]

Mobil 3309 or Toyota Type T-IV or Volvo 116-1540-8 fluid

I can put Toyota IV or Mobile 3309 ATF in my Volvo?

You bet. Asin & Warner (who makes the XC70 transmissions) are sub-division of Toyota Motor Corporation hence why our transmissions can take Toyota T-IV fluid or Mobil 3309. The Volvo fluid is actually rebadged Mobil 3309 at 3X the cost.

Toyota Type T-IV: $5-7 a quart
Mobil 3309: ~ $7 quart.
Volvo 116-1540-8: $20 a quartMore info here: http://www.volvoxc.com/forums/showthread.php?t=11368

[Forkster]

Depends on the MY (manufactur year).

Manuals for MY01-04 states to use ATF in the power steering fluid reservoir. (THIS IS INCORRECT)
Manuals for MY05-07 states to use Volvo synthetic power steering fluid (Pentosin CHF 11S) P/N 1161529 or equivalent.

Some have stated that using ATF in any XC70 should be fine. Our recommendation is if you wish to put a new fluid in your power steering system, use only one type: drain the old stuff and put in all new - it is very hard on your PS system if you mix your fluids.

We do recommend the use of Pentosin CHF 11S/ Volvo P#1161529 in all XC70 01-07 models.

[RIMMONKEY]

I have a humming noise coming from, what seems to be the tires. They are a little overdue to be replaced. I had a free Spring check up at the dealer today. They said I needed left rear wheel bearing ASAP and the left front may also be bad. I ask how they came upon this and was told they heard it during a road test. I can spin the rear wheel with little effort and haer only a ever so faint rub sound. 2007 XC 70 95,000 miles.

[Forkster]

http://www.volvoxc.com/forums/showthread.php?t=5668

It's a do-it-yourself method, saving hundreds of dollars.

[Forkster]

More questions:
1. Have you flushed your transmission lately? If not, use the GIBBONS method above.
2. The type of fluid you can use to flush/fill your transmission: http://www.volvoxc.com/forums/showthread.php?t=11368
3. Have a Volvo shop update the software.
4. Save part of your old fluid in case you need to get it analysed.
5. Your transmission should start shifting normally again after a flush.
6. For MY01/02, there is a known issue of the B4 Servo Cover causing shift flare issues (gears 2-3). Details and how-to here:http://www.volvoxc.com/resources/how-to/pdf/b4-servo-cover.pdf

[Forkster]

Before changing your transmission, there is a known issue of the B4 servo cover causing shift flares in MY01/02 XC70's. It's a $18 part and 30 minutes of work. Details here: http://www.volvoxc.com/forums/showthread.php?t=9192

But if all else fails, especially if you're driving a MY01/02, the transmission needs to be replaced. Take the old fluid from step 5 in the previous reply, and have it analyzed - or just get your transmission replaced. Unless you know of a high-performance european/Volvo specific transmission shop, we can only recommend replacement - not rebuild.

Expect to pay anywhere from $4000-6000 for a replacement installed. :(

[Forkster]

Reference: http://www.obdii.com/background.html
"On-Board Diagnostic systems are in most cars and light trucks on the road today. During the '70s and early 1980's manufacturers started using electronic means to control engine functions and diagnose engine problems. This was primarily to meet EPA emission standards. Through the years on-board diagnostic systems have become more sophisticated. OBD-II, a new standard introduced in the mid-'90s, provides almost complete engine control and also monitors parts of the chassis, body and accessory devices, as well as the diagnostic control network of the car."

For our Volvo's, they provide basic information and trouble codes. Before posting "this is wrong with my Volvo" questions - it will be helpful to pull the codes from your Volvo using an OBDII reader.

[Forkster]

Yes, but the beam pattern isn't the best. Owners who picked this as an option without the projector lamps have reported that the beam pattern is a) problematic to aim and b) poorer than their OEM halogen lights - but much brighter. For example, in my OEM equipped HID XC70 MY04, it uses the same halogen housing. The lights look strong and powerful, but it's no where near the quality beam that comes out of an MY07 HID equipped version.

If you are going to install a HID kit, it is also recommended to install MY07 projector HID headlights to get the full benefit of a properly aimed and projected light.

[Forkster]

NO.

HERE: http://www.computernewbie.info/wheatdogg/2006/07/14/the-latest-scientific-breakthrough-scam-water-gas/

HERE: http://en.wikipedia.org/wiki/Water-fuelled_car

HERE: http://answers.yahoo.com/question/index?qid=20080505085414AA0c3Hl

They're no different than Tornado fuel system savers. Save your money and take your partner/family out to a nice dinner.

[Forkster]

For years, tire dealers have been quietly selling old tires to us the consumer. It has come to the public's attention that all tires have a lifespan of around 6-7 years old - meaning if they're older, the thread can separate from the tire causing your vehicle to crash at highway speeds.

On the side of the tire, usually on the inside wall near the rim edge, should be a 4 digit date code; for example, 0108. The first two digits indicate the week and the last two the year - this is the week and year the tire was made: first week of January 2008. The older code system used a 3 digit. For example, 128 means twelfth week, 1998. If your tires are older than 6 years old, they should be replaced A.S.A.P., including your SPARE. The last thing you want happening is to get a flat, and then have your spare blow out on the highway.

When purchasing new tires for a dealer, ALWAYS ask for the datecode of the tires they're putting on. If they're not current year, well, they're selling you an older model - could be time for some bargaining, or demanding they sell you new tires. New tires mean tires made THIS year. Not last.

More info here: http://www.volvoxc.com/forums/showthread.php?t=11892

[Forkster]

XC SRI (Service Reminder Indicator) Reset Procedures

Resetting the service reminder indicator (SRI)
Hint: The indicator can also be reset using VADIS vehicle communication.

Resetting the Service reminder indicator (SRI), model years -2001
The service reminder indicator (SRI) informs the driver that it is time for the car to be serviced. The lamp remains lit for 120 seconds when the ignition is switched on. Note! If the lamp flashes, it may be because one of the service parameters has not been programmed.

Proceed as follows to reset the service reminder indicator (SRI): Ignition position I
Press and hold in the reset button for the trip odometer
Ignition position II
The service reminder indicator (SRI) starts flashing when the reset button for the trip odometer has been pressed for 10 seconds
Release the reset button for the trip odometer within 5 seconds. The instrument gives an audible signal when resetting has succeeded. Note! If the trip meter reset button is not released within 5 seconds the indicator is not reset. However the indicator will stop flashing.

Resetting the service reminder indicator (SRI), model years 2002-
The service reminder indicator (SRI) informs the driver that it is time for the car to be serviced. The text message is displayed for 120 seconds each time the ignition is switched on. Proceed as follows to reset the service reminder indicator (SRI):
Ignition position I
Press and hold in the reset button for the trip odometer
Ignition position II. Note! Turn the key to position II within 2 seconds.
Hold the reset button for the trip meter pressed in until the original value has been reset. Note! For all vehicles from the 2003 model year a general yellow lamp will light when the reset button must be released.
Release the reset button for the trip odometer within 4 seconds. The instrument gives an audible signal when resetting has succeeded
If the trip meter is already reset the reset button should be held in for a minimum of 10 seconds and a maximum of 14 seconds. Note! If the reset button for the trip odometer is not released within 4 seconds, the service reminder indicator (SRI) is not reset.

[Forkster]

There are three fans that can turn on to help reduce engine heat, and to remove moisture from the A/C system after shutting off your vehicle.

The engine fan can stay on for up to 30 minutes. Sometimes even longer.
The AC can run its fan for up to an hour to get rid of moisture - especially in hot weather.
The interior cabin fan can turn itself on 30 minutes after parking for the same reason.
It's all normal and has a minimal impact on your battery.Why? Ever been in a car with air conditioning that stinks? Ever notice your Volvo's A/C doesn't stink? :)

[Forkster]

AWD - All Wheel Drive. Used to describe the type of traction your vehicle has - in this case, the Volvo AWD transmission setup.

DSTC - Dynamic Stability Traction Control

HID - High Intensity Discharge: usually associated with headlights

MYXX - Manufacture year 20XX. For example MY04 means Manufacture Year 2004. It is often used to identify the year your XC70 was made in discussions.

OBDII - On-board Diagnostics version 2. It is the type of interface that a 'code' reader plugs into your vehicle to read engine codes.

OEM - original equipment manufacturer. In this case automotive components built to the exact specifications from Volvo including Volvo and third party built components.

[Forkster]

Depends - keep a very very close eye on it. If it's weeping like this one (see attachment from a forum member's pic of his leaking bevel gear), check the level - top up, and get it replaced. Check around your bevel gear area - if you see gear oil on the plastic protector you just removed to see it, get the seal re-done. It's around 4-5 hours of labour - should cost you ~$400 depending on dealer rates. Independent shops will do it for less. Some have even done it themselves but that's for the smarter than your average back-yard mechanic bear. :)

If it's just weeping (like a oil pan seal), and not dripping, and if you measure the amount of oil in it and its OK, you can just keep checking it every oil change or 4 months - what ever comes first. You may have to change the seal, but you can put it off for some time.

If there is no oil in the gear, and your rear wheels are not spinning, you need a new Bevel Gear. Costs around $2400-$2800 - depending on dealer costs. Independent Volvo shops will be less.

However, these gears are designed to last the life of our Volvo - but as with any complicated and sophisticated European luxury auto, especially an AWD model, you need to ensure it is checked regularly as they tend to be service intensive. Volvo's require a lot of TLC - the Bevel Gear is a known issue - make sure you take notice of any weeping/leaking of this component. Repairs are costly if it fails.

[Forkster]

http://www.volvoxc.com/forums/showthread.php?t=11783&highlight=coolant+flush - it's a work in progress.

[Forkster]

If you visit your local Volvo dealer, ask them to run the VIN for you. If you live in North America, check out Ford's site:

http://www.ford.com/owner-services/maintenance-service/recall-information

[Forkster]

Details here: http://www.volvoxc.com/forums/showthread.php?t=11758

Wire colours as indicated.

[Forkster]

Volvo uses TORX screws - meaning that unless you have a TORX driver set, those screws are not going to come out easy. Some require special Torx tools as well, such as the cross bars (more here: http://www.volvoxc.com/forums/showthread.php?t=13688).

[Forkster]

http://www.volvoxc.com/forums/showthread.php?t=11939

Lots of info on how to remote it according to VADIS procedures and a simple reset feature.

[Forkster]

All XC70's security system rely on the car's key talking and mating up to the car's security computer. Inside the key when it's inside the ignition tumbler, a transmitter sends a signal to the immobilizer antenna ring which talks to the security computer which allows you to start the car. If the antenna ring becomes faulty, the car will act like you have the valet key inside. haoz129 took apart his ignition column quite easily which allowed him to see where everything is connected.

http://www.volvoxc.com/forums/showthread.php?t=11344

The immobilizer antenna ring often becomes faulty - it's a $100 part but when fixed, it saves one of the more fustrating glitches in the car's security system. The above link was for someone who was having difficulty moving their key from position I->II - but it shows how you can easily take apart and replace your immobolizer antenna ring (step 3).

Although VADIS does not state to disconnect the battery, it is still wise to disconnect it if you are performing any electrical work on your XC70.

[Forkster]

If you are to perform any electrical work, please follow this procedure.

1. With the car on, or key in position II, turn off your fan, close your sun roof, turn off your radio.
2. Turn key to position 0 and remove key.
3. Disconnect negative battery connection.
(DO WORK on car)
4. Insert key to position II
5. Reconnect negative terminal on battery
6. Turn AC fan to max, then to min
7. Fully open and close your sunroof
8. Set the Clock
9. Program the Radio
10. Set seat memory

[Forkster]

http://www.volvoxc.com/forums/showthread.php?t=12120

It's a small bulb in the middle of the tail light cluster. See above link. Easy peazy to replace and a couple of bucks. When you do one, do the other side as well.

[Forkster]

If your engine is sputtering with random engine stalls, your MAF may be dirty. Howard did a great little how-to with pics on how to remove the MAF and then clean it. Note - you need to use proper MAF cleaning solution spray to properly do this job.

Here are some codes that it may throw:
ECM 1300 = MAF
ECM 904D = acceleration pedal sensor
ECM 982A = control module

http://www.volvoxc.com/forums/showthread.php?t=14616

[Forkster]

NO. But if you want to spend $3500 on a rebuild, go-head. It's actually a band anchor for 3rd gear.

http://absoluteautoservicessa.com/Trans_band.gif
Removing it will DESTROYyour transmission.

Please read here: http://www.volvoxc.com/forums/showthread.php?t=15297

[Forkster]

All of this came from a conversation between Mr. Tippy and myself @ SWEDESPEED.COM the past year trying to resolve radio swapping issues. Conversation can be found here (http://forums.swedespeed.com/showthread.php?133953").

Certain Volvo head units can easily be replaced to fix a problem or upgrade the audio performance.
00. P2 Volvos have head units (HU) that are connected with their peripherals (e.g. 10 cd-changer, sat radio, amplifiers, etc) by one of two methods: MELBUS (Mitsubishi Electronics BUS) or MOST (Media Oriented Systems Transport (http://www.mostcooperation.com/home/index.html))
0. The MELBUS system is used in P2 Volvos after 2000 and is being replaced in late model Volvos by MOST based in car entertainment (ICE) as follows (information courtesy of iMIV/Sensolutions (http://iMIV)).
MELBUS
S80 1999 to 2005
S60 1999 to 2009
V70 1999 to 2007
XC70 1999 to 2007
S40 2001 to 2004
V40 2001 to 2004
MOST
XC90 2002-
S80 2008-
V70 2008-
XC60 2009-
V50 2003-
S40 2004.5-
MELBUS Head Units
HU-850, HU-650
HU-450
HU-803, HU-603/613
HU-403/413
HU-801. HU-601/611
HU-401/411
HU-655
HU-555 (only one peripheral channel)
HU-1205
HU-605, HU-615
HU-405, HU-415
HU-105
Volvo MELBUS HU Technical Specifications (http://vccs.volvocars.se/accessories/cat/en-GB/P2X/audio/radio/default.htm)
1. When changing out a MELBUS head unit in your P2 Volvo, ensure that the new one is from the same model year (MY) as your car. The electronics may differ slightly from MY to MY and the faceplate colors may also be subtly different, e.g. V70/S60 HU-613 or HU-803; MY '00-'03 charcoal vs. MY '04 slightly darker graphite).
2. Volvo Online Technical Info (http://volvotechinfo.com) often indicates that a software (s/w) download (d/l) is required when changing any HU, but all same MY swaps of used HUs reported in these forums worked without additional s/w downloads.
3. When HUs from different model years were exchanged, the steering wheel controls and HU faceplate lighting were lost. This is not surprising as these functions are CANBUS dependent. If possible, check VADIS or VIDA (Volvo technical information systems) to see what HU part numbers are interchangeable for a given MY.
4. All Volvo MELBUS head units can be replaced with an after-market unit. However, in order to retain the steering wheel controls, backlighting and NAV sound, you will need an CANBUS adapter, e.g. Dietz CANBUS products or Volvo AEM (auxiliary electronics module) to supply the speed, reverse control signals, headlight signals. Volvo OE head units can often be found on ebay, a salvage yard or for sale in the Swedespeed classifieds for much less than the cost of an aftermarket HU & adapter combo.
5. You can only upgrade or exchange radios that were offered as original equipment for your car's MY, i.e. a 2004 V70 can take an '04 HU-613 or an HU-803, both with graphite faceplates, but not an HU-850.
6. Faceplates are apparently not swappable between model years or different HU models. Compatibility is also probably dependent on the other internal electronics, not just the faceplate.
7. You do have the option of buying a new replacement radio from Volvo and having it programmed (s/w d/l) into your car. It is unclear at this time if any P2 vehicles with MELBUS radios can be reprogrammed to accept a used same model radio from a different model year, e.g. an '03 HU-803 for an '02 HU-803. We do know that '03's are not interchangeable with '01's.
8. Even through some radios may be the same model #, they likely have different firmware and different electronics. The picture below shows the backside of the faceplates of two HU-803 radios that I tried in my 2004 Volvo. They were not interchangeable and the steering wheel functionality and backlighting were lost with the '01 HU-803; however, no software d/l was performed. The core radio functions, i.e. FM/AM/CD/10-CD Changer, still worked.
9. Volvo HU-600 series HU's have an internal 4-channel amplifier for the front and rear speakers, the HU-800 series HU's have one internal amplifier for the center channel and use an external amplifier (under the right side front seat) for the main speakers. The external (auxiliary) amplifier, PA-200 (4x50w @1%THD) or PA-300, (4x40w @1%THD) can be added to an HU-600 series head unit--caution: the OE speakers may not be rated for the higher output so the listener must be careful with their maximum volume levels.
http://members.shaw.ca/mr.fork/hu803.jpg

[Forkster]

http://www.volvoxc.com/forums/showthread.php?t=8001