20 Most Recent 2004 Volvo XC70 Questions & Answers

Volvo has had a lot of trouble with relays in the rear control module. Check/replace the relays for the rear lights with the updated relays.

Yes there 2.3 and 2.4 liter engines some turbo some non turbo thanx Chris

If you look just behind the headlight glass from the top, you will see two holes with 7mm hex head screws. These will adjust your headlights up, down, left and right.

Wiring, schematic, electrical diagrams, fuse diag, error codes, torque settings etc are basic contents of these online books they have here on this website www.reliable-store.com I have attached. Must check it out

wiper fuse but it will stop your front wipers. best way is to pull panel and unplug that motor.

Purchase an after-market switch set from an auto parts dealer like NAPA or Parts plus, any one of them would get you a switch set a lot cheaper than OEM. Before I'd pay $300 for a tumbler barrel I personally would remove the switch and use a screwdriver to start my car. I've done that also.

See if you can pull the airbag fuse to avoid accidental deployment of the airbags. It sounds expensive.

If it is a automatic transmission could be the torque converter. The most likely cause is the shift

Put up to three bottles of Lucas no slip.

The easiest way to me is to remove the bumper and then the headlight is held in with 3 small bolts. Remove them, then the bulbs are easily accessible. You *might* be able to snake your hands in behind the headlight but you will curse a lot. It also help to know exactly how it looks in the back (maybe google some pictures of the back of the headlight) so you know how to reach and untwist the little bulb holder. Or drive in to the dealership and ask them to replace the bulb for you. Sometimes they just do it then and there.

I recommend strongly you see the dealer, I think the BCM has lost programming. The dealer can re-flash the BCM module.

Try the fan relay first in case its stuck on. There is a fan switch module as well. Could be in the engine bay by the battery? Thermo switch is usually on the thermostat housing. Look at google images or pop into a dealer and ask a tech

My guess here is that they are getting wet at the connection point at the light and shorting out. I would climb under, dry and clean them and then electric tape them well.

In the trunk lid just to the right of the license plate you should see a plastic cover over the trunk lock cylinder. You can use your key to open the trunk.

Yes fear a recurrence. These things don't happen for no reason. Modern fuel injection operates at high pressure usually 40 to 100psi - up to 3 times the air pressure in you tires. In most cases if you had even a small leak gas would spray everywhere. Either take it to the dealer not a local mechanic or if you are on a budget invest the time to join a car owner forum free online and begin searching there and google. Sometimes forums will know the problem and say do A, B and C and it will not happen again. If that fails go to the dealer. Even if you end up at the dealer you will still have better insight into the problem and possible solutions. Normally, fuel injection is super reliable - basically bullet proof for most or all the life of the vehicle. Post results.

You might find that the throttle sensor which is electronic and part of the accelerator pedal has become unresponsive due to lack of use.i had this problem with a ford maverick which had been sat idle for a few months. And this caused the engine management light to come on and throw into limp mode.my cure was to press the pedal up and down quite hard with the engine switched off.also did this to the clutch pedal.cured the problem but every so often for the first year of regular use it would repeat.so I just pumped the pedal fully up and down whilst engine was off.no more limp modes.

Hello Posters,

What you are experiencing in one way or another is a low (all functions inside the passenger cabin) or high speed (engine compartment) network failure. But before I get to far into it you need to understand how the Volvo works and don't worry I will keep this as lamen as I can.

The 1999 and new Volvo's work on a network, (CAN network) think it of a a bunch of computers in an office that share a printer. Well, depending on the year of your Volvo you could have up to 20 plus computers or ECU's. The reason that such technology is on your car is siimple: The average car today carries over 400LBs of wiring that runs to and fro through out the car. This weight is no longer acceptable and if not stopped could easily make up over half the weight of the car to give us the comfort features we want.

Don't panic yet, Volvo didn't just stuff that many ECU's in a car without a diagnostic solution just in case something went wrong. Now, since these ECU's have information that needs to be shared over the car there needs to be a boss of that information. Think of 20 people in one room all talking at once, everyone is talking but no one can hear. With me so far?

So, Volvo put what is called a CEM which stands for Central Electronic Module to 'run' things. It's job is to monitor and regulate all communication on board the vehicle, with out it there would be anarchy!!

How to they talk to each other?

Two wires are run between each ECU (LAN Cables if you wish) which pulse voltage up and down to give it's ECU's information package when it's that particular ECU's time to 'speak'. The CEM controls who speaks and when. If one ECU speaks out of turn then the ECU who's turn it was to speak is silenced. If this happens to the next ECU on the list and so on here is the anarchy I spoke of. (If you and 20 of your friends were sitting around a room and you each had to say a number higher (1.2.3.4.5.6.6.6.6.6.6.6.6.6.6.6.6) than the person to you left and the one person just kept shouting their number the cycle would break down.

The CEM would then instruct all ECU's to shut down since there is no point to speak with the loud mouth in the room. This is example is a babbling node (ECU). Since the on board's information is transmitted using voltages then any disruption or damage to the signal will cause the network failure. Short circuits, either to power or ground, would stop that electrical signal although shorts to ground is the most common.

If the dash is going dead, you should see the SRS light/message come on first then the gauges drop off then the total death of the display.

High speed failures will show as the ABS/TRACS failure message then RPM and engine temp fail but the rest of the DIM will stay on.

You really need to take this to the dealer and the dealer ONLY!! They have computer (VIDA) that can run the necessary diagnostics to determine where the problem may lie. If the fault is permanent then it is relative easy to find and fix. If it happens every now and then it is quite difficult to find. But, if your technician says it's a computer right off the start then he is guessing and you should get a guarantee that if the computer replaced does not fix the problem then you will not pay for it.

Let me know if this helps.

Gazzer