This is intermittent but frequent, My daughters s60 will run perfect and then occasionally start surging, The dash and headlights are fluctuating as well. Any ideas?

 

If Volvo cars have a ECM power relay I would look there, had a Mercury Cougar that displayed the exact symptoms when the ECM relay was failing (PCM relayin a Ford, though same thing) It eventually left me stranded. Otherwise I would look for loose power/ground cables and wiring to and at the ECM.

 

Where is the ECM located? I can check connections and clean with contact cleaner.

 

The ECM is in the engine bay, right side of the vehicle. It is inside a black box.
Now, when you say the engine surges are you describing erratic idle? If so, that can be caused be a dirty throttle body or mass air flow sensor.
When I had the bad ECM relay the dash would go dead and come back on. After re-reading your post it sounds like what you described is dimming of the lights caused by low voltage due too low idle speed.

 

Have you resolved your problem?

The surging could also be the Electronic Throttle module (ETM). There is a recall out on that.

 

Not resolved yet, I guess I will need to see if this vehicle falls under the recall. It has kicked out codes for the ETM. I wonder if Volvo will remair that under the recall since it's older?

 

Alternator. I know it's not the same car, but the same thing happened on my old Accord. When the alternator was going the lights would "pulse"

Have it tested.

 

The ETM Recall is 10 years or 200,000 miles. Get it checked out before it is too late. I just got a new ETM installed on my 2001 S60 and in a few months I would have had to eat about $1,500.

If your S60 is 01 or 02 there is also a fuel pump replacement recall as well.

If you want to be sure about your car's in service date purchase a carfax or autocheck report.

Also a cool trick is to do a google search on your vin #. My Gold S60 still shows that all 3 recall campaigns are still outstanding so that car is going in next week.

 

It was the ETM, They did replace it under warranty and I just skimmed by on the warranty period as well. Runs like a champ now!

 

That is great news. Since some of our still invested in our 2001 Volvo S60's we need to cheer on when something goes right.

 

right on bro

 

This could be one of the causes of the surging:

I just replaced the Brake Booster on my 2000 S80 2.9L. It was easy for me and took 2 hours. The reason I needed to replace it was there was an intermittent hissing sound (Vacuum Leak) heard inside the cabin usually after releasing the brakes. It would stop if I just quickly tapped on the brake pedal. There was the "Service Engine" light and also an "Emissions Service Required" message on the display.

Not just that but the biggest problem I had was the Surging & erratic Idle. Got so bad that the lights would dim and the car was dying the day I replaced it.

After the change the car idles & runs perfect. No more messages and it passes inspection with flying colors.

Thank you all for the posts

 

Kenwood's problem is resolved but you may have revealed the problem I am experiencing with my daughter's 2002 V70. I could swear that I heard a hissing sound like air was blowing near the steering wheel.

 

I would suspect the brake booster. See if tapping on the brake pedal stops the hissing? Mine was intermittently loud. I could really hear it. When the car surged at stops, I could get it to stop the hissing and surging by pressing hard on the pedal. Seems to be a common problem and complaint.