Recently my check engine light came on and when I took it to the dealer he analyzed and reset the codes on the temp sensor. All was fine for a few days and now the light is on again. I believe it will require a new thermostat, however, do I need to replace the ETC sensor as well?

There is a software update to address the coolant temp. setting if you have the right code...

Where can I find more information on that software? Call Volvo? I'd like to know my options before coming to the dealer. I have code PO128.
Thank you

Where can I find more information on that software? Call Volvo? I'd like to know my options before coming to the dealer. I have code PO128.
Thank you

The only place to go is to the dealer, the software should be somewhat cheap. I would guess around 100.00

Before you follow up on the software, check if the thermostat is working. The engine should reach normal operating temp (middle of the guage) at idle. Then drive down the road, the guage should remain in the same position. If if falls to the left, then replace the thermostat. If it remains constant do the software.

The thermostat seems to be OK: the engine warms up in a reasonable time and temparature gauge stays at 3:00 position.
In other treads of this forum about the same problem (PO128)somebody referred to the Volvo campagn 109.
Do you know anything about it?

Last winter 2003/2004 I had CEL coming up three times within 2 month:
1)CEL came on along with the Arrow (lower gear switch). The dealer has read the codes AT 313, ECM 76, ABS 313, 314 and traced it down to internale faalt in the Gear Postion sensor. Replaced the PNP switch
2) In month, CEL came up again. The dealer read it as C ECM 0D, A1 and traced it to a permanent fault of EBP (engine boost pressure) sensor ( i have turbo).
They replaced the sensor and warned me if ECM A1 returns, I'd need to check on ECT sensor and thermostat and may need to replace both.
3) Shortly after, CEL came back on. That time I did not take the car to the dealer, rather followed my friend advice and filled the tank up with the higher grade gasoline. After a couple of trips on the highway the light went off, and did not come back till now. My friend told me that the higher octane fuel can help to clean the sensors etc in the emission system.
I tried the same this time, and have not gotten any effect so far. The SEL stays ON. My friend also told me that if the higher octane fueld does not do the work, then I may try the fuel additive that helps to clean the system.

Thank you.

I know that if it is a recall it is free to you. Either way it sounds like a software update and it should take care of your other update as well. Just call the dealer with your VIN number and have them check for recalls.

Thank you, I'll do.