V70 2004 won't start

pjcat · Post by **pjcat** » 24 Mar 2019, 16:56

Our V70 just stopped working. Parked it in the garage and next day it doesn't start no more.
First I thought either fuel or spark. So I removed the spark plug cover and hooked up an ignition tester to one of the spark plugs. It acted erratically; sometimes there was some spark sometimes not. So i doubted if this is the correct way to test for spark???
I looked on the internet but didn't find any specific procedure for this model. How to test the ignition on this car?
Then i tried to look into the fuel system; I found the fuse for the fuel pump and it's still good. But I couldn't find out which one is it's relay and how to test it? How to test the fuel system on this car?
Then i hooked up an OBDSCII-reader and it didn't give any error message. But by doing that, I noticed that something else is going on with the electric system: when i turn the ignition key the warning sign on the dashboard blinks erratically. And when I press the button to read the error messages the whole thing starts to blink even more. I can also her something clicking like a relay behind the dashboard. i made a video so you can watch this here:
I don't know what to do next, so any advice is much appreciated.
Thanks
Pat

veektor · Post by **veektor** » 26 Mar 2019, 09:40

I recently did the engine swap on '08 S60, and had removed ECU/TCM out to avoid damaging during engine removal. When I put everything back together, I tried seating ECU/TCM by hand, but couldn't get them all the way in. I tried starting the new engine, and over a couple of days it went from starting fine to acting like it had no spark. I had ordered the ECU removal tool, reseated both units, and haven't had any more starting problems.

You can get a fuel pressure gauge to test, or just do a binary check with a screwdriver and a rag. That will tell you if there is any fuel at all at the fuel rail. By what I see in the video, your problem does appear to be electric in nature. I'd try reseating the ECU, and hope it doesn't need replacement.

Actually, before you go down that route, check your battery voltage. Modern cars are very sensitive to low voltage. You may have enough to engage the starter and crank over the engine, but that may still be too low for ECU, and can cause some unusual behaviors.

pjcat · Post by **pjcat** » 26 Mar 2019, 11:10

veektor wrote: ↑26 Mar 2019, 09:40 I recently did the engine swap on '08 S60, and had removed ECU/TCM out to avoid damaging during engine removal. When I put everything back together, I tried seating ECU/TCM by hand, but couldn't get them all the way in. I tried starting the new engine, and over a couple of days it went from starting fine to acting like it had no spark. I had ordered the ECU removal tool, reseated both units, and haven't had any more starting problems.

You can get a fuel pressure gauge to test, or just do a binary check with a screwdriver and a rag. That will tell you if there is any fuel at all at the fuel rail. By what I see in the video, your problem does appear to be electric in nature. I'd try reseating the ECU, and hope it doesn't need replacement.

Actually, before you go down that route, check your battery voltage. Modern cars are very sensitive to low voltage. You may have enough to engage the starter and crank over the engine, but that may still be too low for ECU, and can cause some unusual behaviors.

Thanks! I will look into that.

Post by **oragex** » 26 Mar 2019, 12:11

Looks like the common CEM water ingress (google up)

turbo engine? awd?

pjcat · Post by **pjcat** » 27 Mar 2019, 11:58

oragex wrote: ↑26 Mar 2019, 12:11 Looks like the common CEM water ingress (google up)

turbo engine? awd?

It's a non-turbo 2.3l FWD

Post by **oragex** » 27 Mar 2019, 22:06

Maybe look at the CEM with a flash light for any traces of water on it, and also measure the alternator voltage with the engine running. If the CEM is in cause, usually Xemodex may fix it, but removing the unit from the car is not easy (look up on Youtube)

pjcat · Post by **pjcat** » 02 Apr 2019, 02:31

Finally found the time to check on it; here is what happened:
The battery is fine. charged it and didn't change anything on the situation.
Next I looked at the CEM: took it out which wasn't to difficult and inspected it. It looks very clean with no visible corrosion etc. here a picture:

So I put it back together. Now when I tried to start the car, the erratic behavior it had before wasn't there anymore; no blinking of the warning sign and no clicking from a relay. But the car still wouldn't start.
I hooked an OBDSCII-reader up and it didn't show any error codes.
When I turned the ignition key to on, I noticed from the engine compartment a high pitched humming noise, which seemed to come from the ECM area. Maybe this is normal but I am not sure. I tried to pull out the ECM by hand as I don't have a tool, but that did not work.
Now today I went back to the car to record that humming noise and as I turned the key... the car started.??????
That is of course great. Just not to know why all this happened is not so great; I don't like to get stranded in town. I still want to remove the ECM and have a look at it. Maybe me trying to remove it changed something on the contacts. So I ordered a tool, or is there a save way to remove it with out that tool?
I also hooked up the OBDSCII-reader again and now I had an error code: P0037 - Heater Control Circuit Low (Bank 1 Sensor2). Anybody knows what that means?

Post by **RickHaleParker** » 02 Apr 2019, 02:52

Yes the electrical gremlins may of been bad/dirty contacts on the ECM and/or the CEM.

Get a can of MAF Cleaner and/or Electrical Contact Cleaner and keep it in storage. In the future always clean a electrical connector when you pull it.

MAF cleaner would be the better of the two if you only get one of the two because: You can and should clean the MAF sensor periodically and you use MAF cleaner and nothing else for a MAF sensor.

P0037 = Rear O2 Sensor heater, Low voltage. In light of your recent electrical gremlins, I suggest you clear the P0037 and see if it comes back.

veektor · Post by **veektor** » 02 Apr 2019, 09:45

pjcat wrote: ↑02 Apr 2019, 02:31
When I turned the ignition key to on, I noticed from the engine compartment a high pitched humming noise, which seemed to come from the ECM area. Maybe this is normal but I am not sure. I tried to pull out the ECM by hand as I don't have a tool, but that did not work.
Now today I went back to the car to record that humming noise and as I turned the key... the car started.??????

Was there still a humming noise, though? Or was the noise only present when the car was failing to start?

One of the first problems I had to solve on my S60 was the parasitic drain on the battery. One day I was poking around the engine bay and heard a faint hum. It was coming from the alternator. When I unplugged the negative connector from it, the hum stopped, and so did the parasitic drain. As I kept digging, I realized that PO installed the wrong version of alternator, which may have caused the regulator to fail and cause the shorting. I've replaced with the proper post-2005 model, so far running like a champ.

As for reseating the ECM, I have no idea how people manage to do that without the tool. Those plastic sliders are really hard to push into open/closed positions.

pjcat · Post by **pjcat** » 04 Apr 2019, 12:14

[/quote]

Was there still a humming noise, though? Or was the noise only present when the car was failing to start?

[/quote]

Yes the noise was still there. I am guessing it is normal. I also made a video of it: