Hello! I am new to this forum and am overwhelmed by the amount of info out there! But I need some help desperately!
My wonderful 2004 V70 (I am the second owner- purchased Oct 2007 with 49,500 miles) stalls while I am driving. It happened 2x in October 2008 and I immediately took it to the dealer where they informed me that no error codes showed up in the system. After doing a bit more digging, I found a recall that did not encompass my particular chassis, but did reek havoc on the same make and model car. So, a good faith repair was done to replace the Fuel Pressure Sensor. I drove the car without incident until last week- it happened again.
I must mention that each time it stalled, I was driving about 30mph and braking. When it stalled, it was as though I just stuck the key in the car to start it as all dashboard lights went on - then off. I had no steering or braking function - which was quite scary particularly the last time it occurred as I was in the middle of a turn. I am thankful that there was not a pedestrian in the crosswalk or a car at the intersection as I was unable to steer or stop. I almost hit a parked car.
I brought it to the dealer yesterday and they have done all kinds of diagnostic tests on it and of course have driven it - without incident or error code. So, they say nothing is wrong because they cannot duplicate the problem.
Please advise as I am afraid to drive my car!

 

Welcome to the forum, and just to let you know I moved your post from New Members Area. I apologise if this have confused you.

Please note that I am an 850 driver and am not privy to the newer generation V70s so please use this as a reference only.

I did check the recalls and you are right, only one recall that would affect engine performance:

http://www.autobuyguide.com/2004/12-...lls/index.html

>When it stalled, it was as though I just stuck the key in the car to start it as all dashboard lights went on

This happens to almost all cars. When you turn the key to ON before starting (not the START position), you will see all dash lights to let you know if there is a burnt out bulb. And after you start the engine, the key moves back to the ON position by spring tension. When you are driving the key is at ON position and if the engine stalls then you would see the warnings.

Yes, it is scary to lose power assist for the steering & brakes. When the engine dies, the power steering pump stops, and the brake booster loses vacuum from the engine. When this happens again, try exerting as much force as you can to navigate the car to avoid accident. If you have enough time to react, shift to N (Neutral) and try re-starting the engine. If the engine re-starts, shift back to D (Drive). You do not have to press the shifter button to move between D & N. If you are going downhill/has to stop the car immediately, pull hard on the parking brake (not suddenly but gradually), as this would at least slows down the rear wheels. But consider this as a last resort, because this will render your car to a tail skid.

Until the cause has been identified, try visiting an auto parts shop such as AutoZone to have it diagnosed; free of charge (but I have heard that they may have discontinued this service so call them first but other franchise shops may still have this service).

Most likely the problem is within the Electronic Engine Control-EEC, and once in a blue moon a fault may not be reported to the ECU-Electronic Control Unit. But it could also be something outrageously simple.

Cars are known not to duplicate the problem when technicians are working on it.

BTW, is your battery still original? If so, I would replace it even though it probably has nothing to do with the stalling. An average life of a battery is 4-5 years (as much as 8 years for maintenance-free type). I would buy one from the Interstate Battery and avoid cheap franchise one, as they could fail prematurely.

See what Moderator Tech/other V70/S70 expertshave to say on this problem. In the meantime, I will attach a page from 850 manual. This may or may not be a good reference to you but why not. I hope other V70 (S70) members reply to you to rescue.


JPN

[IMG]local://upfiles/6892/AD1D5AF7A806414FA7532C538598B58E.jpg[/IMG]

 

During other times does the idle drop really low when coming to a stop?
Did if feel like it was running out of gas before it stalled?

 

I had my '04 S60 back at Volvo today after the 4th stall on a turn. It happened twice in the spring of '08 slowing to make a right hand turn. I brought it to the dealer and as you state, nothing showed on the computer, so no repair was made. (My fuel pressure sensor was changed in '07.) In December it happened making a left turn, and more recently on another right turn. Each time my foot has been on the brake. The first three times it was after a 30 minute drive, the last after a 10 minute drive. Today, again, "nothing is wrong because it cannot be duplicated."

There MUST be a reason. Any further issues for you, or advice you have received?

 

My 2004 v70 was purchased certified used and has a very similar problem. What I noticed initially is the car would stall out when I came to a stop on extremely warm days where the AC ran hard, and restart easily, but idle very rough and stumble as if it starved for gas. It stored no codes. At this point the car was due for plugs and I replaced them (50k miles). It also stalled when I turned right through water over the road during or after a strong storm.

During normal driving I found the idle would drop below 500 rpm when I came to a stop then bounce until it settled in the normal range. The car would be sluggish from a complete stop. It stored no codes. After several visits to the dealer for service they replaced the fuel pressure regulator. It made no difference. They reprogrammed the transmission, and this made no difference.

I've taken the car to the dealer at least five times....it never stores a code and they never find anything wrong.

About a week ago the car was at 99,970 miles (30 miles left on the warranty) and I drove through standing water and it died. It restarted and I drove it right to the dealer. They said they found a code but were not sure of the cause and would need the car for at least a week. They gave me a loaner to drive.

Today they called and said the car was fixed. The engine control unit was going into failure and was replaced. I asked if the replacement part was new or reconditioned and they told me it was new and had a 12 mo. 12,000 mile warranty. I am picking up the car tomorrow.

 

Hi hovonogila:
Any luck with the engine control unit replacement? Any idea as to the cost of that part? Did they happen to tell you how they discovered it was going into failure?
My car has stalled at least once/wk since January...I am a pro now and don't panic when it stalls. But I am frustrated. When braking, my idle often goes below 500, then bounces back to the 800-900 range. It drives well, but lately I have noticed that my gas mileage is less than last year without altering my driving habits- I figured it was worth noting. Please let me know if your problem is fixed. Thanks for your post!

 

Dear tech:

Yes, the idle does drop down below 500 when coming to a stop. I often feel like it will die right then, but it has been an intermittent problem. It has stalled at least once a week since January 1st. Each time I have been braking or turning (braking during the turn), and after it dies, the only light that remains lit on the dash is a little gas/oil can. It has always started right up. WHat do you think about hovonogila and the engine control unit?

 

I agree there MUST be a reason....and yes, it has stalled at least 1X/week since January.

 

Does the dealer feel the engine control unit was causing/could be the cause of intermittant stalling?

 

They did not replace the engine control unit, as I stated. I wrote my post prior to picking up the car. The technician explained, when I picked up the car, that the block that connects to the ECM had failed. He said he has never seen a Denso ECM failure.

The technician explained that when he tried to download software the ECM would not take the upgrade. He said the CEM failed during the download. He replace the CEM and reloaded the software but the keys would not program during the SW download. He reinstalled the key application software in order to reprogram the keys.

The work order listed these parts:

electronics box (30657629-9)
CEM reload (9494722-3)
antenna (8621509-2)
ecm gasoline up (30677021-5)
ignition key ap (8633525-4)

The idle is perfect, or so much better than before that I can allow for any minor glitch. When I come to a stop the tach bumps very slightly when it gets to the low end range and holds perfectly. The take off from dead stop is smooth and powerful...

 

The thought process presented to me was that the system became bogged down processing information because of the CEM failure.

Normal events such as a ABS signal would put the system out. Not their words, but my own analogy, might be using a defective keyboard on your computer that would prevent the computer from operating correctly and locking up. Even if you reboot, the next time you get a keyboard defective process you fall into the same hole.

 

I have a similar problem. It is really the ECM? It seems odd to me but what do I know. The reason I'm hesitant is because I and others have experienced the same problem while turning. Which would indicate something related to boost and vacuum. Does the ECM control vacuum too?
My car has 150k so I would rather not "try" too many costly repairs before getting it right.
Thanks y'all!

 

The ECM is expensive. It's manufactured by Denso...which I believe is owned by Toyota.

The CEM is kind of a communications block that sends signals to the computers running the car. The idea in my case is that the CEM was failing and this caused the ECM to send the wrong instructions. As the dealer who they reccommend for errors in the engine management system and talk to the mechanic before you spend money.

ECM and CEM are different parts....not same.

 

I was experimenting today and I have an update. Although the RPM does drop while turning, it only drops 150RPM max, which I assume would be OK for a booster pump running hard.
Now back to the braking issue: It seems that it does not just happen when I brake. If I let the car coast to a stop with the engine idle and no brakes, the RPM will drop too (to 500). It is the same drop than if I brake. Now the funny thing is that is seems to always go back to normal RPM (800) when the car stops. In fact it goes back to normal just BEFORE it is at a full stop. Could it be that the ABS sensors stop sending signals when you reach a very low speed (walking speed)?
What does CEM stands for, BTW?

 

I do not know. Take a look at my reply from before, when I listed the stuff they did to fix the idle and stall problem. Maybe google the part numbers and see what you can find. Unfortunately the engine management system is not something you can diagnose without access to the software.

 

Is everyone fixed now? Do I just need to replace that list of items? What will I need to drop for that? Thanks.

 

The CEM seems to have fixed the problem. Car is good.

 

My Volvo has been stalling when I make turns, esp. left-hand turns. The lights stay on as well as dashboard lights, but the engine and steering die completely. I can start the car up right after that. Nothing seems to come up on my mech. diagnostics but it sounds just like what others on this forum have been experiencing. Now it is even idling very low and feels like it will stall even when it doesn't. Volvo says there is no recall on my VIN. I'm afraid to put my kids in the car as it stalled on me in a busy intersection the other day, and 3 times in one hour! We had one pressure sensor replaced as well as the fuel pressure sensor but it's still stalling-I don't want to pay for anymore wrong parts to be replaced. Could it be the ETM (throttle) that needs cleaning or replacing? I found some info on this in other forums.

 

The car would die, all the lights stayed on, brakes were fine, steering became difficult....but it would start right back up, just that the motor stumbled and ran poorly? My car did this.

The technician said he discovered it was the CEM after he tried to get codes off the computer. When there were none he tried to 'reset' the codes to set the system to square-one. When it would NOT accept the reset command, that's when he suspected the CEM. Do a google search on 'CEM Volvo' and you'll find out you are not alone.

 

THIS IS HOW MINE WAS FIXED

I am so glad that I found this forum. My Volvo V70 - 2003 had a similar problem. It would stall at junctions especially when I was turning and braking simultaneously. Two main dealers looked at this and concluded that there was no problem because there were no codes on the car logging system. Finally, after 10 months in and out of main dealers, an independent Volvo specialist solved this for me.

It turns out that there were no hardware faults anywhere on the car, however, there were numerous software issues in several of the control units. The solution was to wipe all the software from these and re-install the lot.

Specifically on my vehicle the garage reinstalled the ECM, TCM and CEM software. (Dont ask me what this means :-), that is what it says on the bill) and I watched the garage download the three software packages from the Volvo system whilst the car was linked to the computer.

The car is now like new. No lumps and bumps in the performance and no hint of a stall at junctions. I have also noticed an improvement in the fuel consumption and the smoothness of the engine on acceleration.

Finally, as if he wanted to give me a bonus the garage charged only the cost of the software downloads and 1.5 hours for the labour. - A bargain at £135.00 overall. I think that main dealers would add a serious markup on the software download and the labour would be far higher too.

If any reader is having the same problem as I had; and lives in the south east of England, please feel free to contact me and I'll pass on the name and contact details of the garage.