2002 S40 P0700, P0118

[regent]

Like I suggested earlier, you need verify your ECT Sensor output and wiring integrity. Thumbs up for using VIDA (or getting some help from an indie with VIDA).
In my experience, most electronics-related issues have become evident after talking to the car in 'her native language'... (since my Swedish sucks, I prefer using VIDA/DiCE)

[Jorge23]

All,
I bought my daughter a 2002 S40. I've had many Volvo's but never one of these little critters. I had the timing belt and water pump changed right after purchase. It has 140K. The car was going into limp mode while driving with the flashing up arrow (which freaked my daughter out). Based on the fact that I could row the shifter many times and it would temporarily fix it, I started reading. It looked like the PNP switch was the culprit. I have just changed it out today, all gears work, reverse lights work, etc. I hope this takes care of that. I hate to think what might be next if it doesn't. It is getting code P0118. I changed the Coolant Temperature Sensor and put in a new thermostat. It did not fix the problem and the fan on the car runs for a long time after you shut the car off and idle is all over the place. MAF would be next? Anything else I should check? Anything else I should know about these cars?

I got a 2000 volvo s40 i was getting the same code P0118 my radiator fan was working for long prior time drain the power of the battery and a/c was not working blowing hot i bought a thermostat and temperature sensor and was still getting the same code took me a little while to figure out and start checking the wires on the temperature sensor and went look closely at the plug 1 of the 2 wires that goes to the plug was broken and not making contact it was the 1 that send a signal to the ecm i went to the junkyard and got it from a volvo and put it back on and the code is gone and a/c and fan working properly again.

[VolvoFredNY]

I agree with mf70, instead of throwing parts at it, purchase a DiCE and VIDA from ebay. I recently purchased one ($150) which is probably on the high end for it, but if you figure a shop gets $120.00 per hour where I'm from - it's worth it, especially if you keep the car for some amount of time. I wished I had purchased it before. That should give you a good start and then tackle one issue.