Now and again my 1998 auto volvo ETS light comes on and goes off again when I switch the car off and start it again. What is the problem?

The ETS light is the warning light for the Electronic Traction Control. Check Engine light indicates there is a problem with the emissions system. Take the vehicle to Auto Zone, Advance Auto Parts, O'Reilles, or Pep Boys and have the ECU scanned to see what codes comes up. The code will tell your what part is being effected.

under the hood youll find a fuze box, there is a yellow 20 amp fuze blowm. it will be in a row of two towards the firewall. believe it is the one one the left.

Call the Dealer and see if they will fix it under the extended warranty or the throttle recall.

very common problem is the switch itself alot of time the little button/switch goes bad.

ets light is fro throttle unit fault you have dirty throttle plates or bad throttle unit /

There are two problems here. First you need and abs control unit. They are very expensive and it is possible to rebuild them. A couple of places to call: ATE, Auto Truck Electronics, they are in Florida, and BBA Remanufacturing near Boston, MA. I have used both companies and they charge much less to rebuild them than it costs to purchase a new one. That should take care of the speedometer, brake light, and ABS light. As for the check engine, that could be anything and the car will need to be scanned. ETS light can be remedied by a trip to the dealer. There is a campaign to install new software to the Electronic Throttle Controller. This is no charge to the customer and I believe the car has to be under 200,000 miles.

Go to your local auto zone the will tell you what is wrong and why the engine light is on >>
> Using a Code Scanner <
and the best part it is free

For the ETS light, its covered in Volvo's callback guarantee for 2000 models upto 10years / 100000 miles

get the code read again where did this come from eng control unite? pay volvo the $90. and get the correct code or give use more info engine /turbo/auto etc...