AC Temp Sensor Problem - 2000 V70 FWD NA

Post by **rolsen11** » 17 Jul 2025, 14:58

Hello, I took my car into the shop today to figure out the problem with my AC.

The problem: When turning AC on, it will blow cold for anywhere between 5-20 minutes, then the air will become humid and weirdly smelly, then after that the air will become warm. After the car has sat for a number of hours, this process will repeat.

The code the shop pulled from OBD is the following: Climate Control Module 135 Engine Coolant Temperature (ECT). Signal Missing.
The shop told me that the coolant temp sensor needs replaced.

This of course leads me to believe that the coolant temp sensor, part number 9125463, is bad. However, the coolant temp gauge in the gauge cluster still works properly. If the coolant temp sensor is bad, then wouldn't that gauge no longer work properly? Is the shop's scanner reporting the wrong description for that code? Is it actually a different sensor that is bad? I have no idea, I don't have access to VIDA to really see. Does anybody have experience with this issue?

Post by **abscate** » 17 Jul 2025, 17:14

Look down at the clutch and see if it is disengaged when the air gets warm

It’s likely your clutch gap is worn and is dropping out after it gets hot.

There is a spec on the clutch gap you can measure which a feeler gauge.

Volvo pulls off the clutch and shims it Back to spec for about 4 hours of labor

Many here have shimmed it on the other side using “ bread clips” or zip ties

Vova585 · Post by **Vova585** » 17 Jul 2025, 19:24

3.5h to be exact. Was just told that by dealer last week. Dealer recommended to save them and myself time and just go with new compressor. I agree with abscate that clutch gap is the first thing that needs to be checked. I think the spec is 0.3-0.5mm

1st-check gap. If it is far away from spec-look at yootube videos about "bread clip fix" or zip tie fix, but ultimately correct way is to remove clutch plate and adjust gap by removing appropriate amount of washers that regulate gap.
2nd- if in spec or close to spec. Take a long wood broom handle and drive around. When ac stops working park and while engine running see of the clutch is turning. If it is not turning try to gently "bump" the clutch towards pulley(careful here. If not comfortable better dont do)if after "bump" towards pulley ac clutch reengages-you have a weak coil(or your gap is off) so ac compressor is your answer

Post by **rolsen11** » 17 Jul 2025, 19:49

Just so I understand correctly, 0.3-0.5mm is the nominal gap? A gap greater than 0.5mm will be out of spec and clutch will begin to slip/not engage at all? I can check with a feeler gauge tomorrow at work.

Vova585 · Post by **Vova585** » 17 Jul 2025, 19:54

Yes. Test on cold engine preferably.

Post by **abscate** » 18 Jul 2025, 02:35

..with the engine not running….

Link to the. Generic bread clip fix thread from 2010 , more info in the related threads at bottom

viewtopic.php?t=31203&hilit=Bread+clip+fix

Post by **rolsen11** » 19 Jul 2025, 11:36

I checked the gap with a feeler gauge after work yesterday (when the car was cooled off), the gap measured between 1.02 ~1.11mm. I'm surprised this clutch was able to close at all. Going to work on getting the zip ties put in today.

Post by **rolsen11** » 19 Jul 2025, 11:57

Quick update: decided to check the gap again since the car has sat overnight now. I suppose the car had more cooling down to do, since the gap has now measured at 0.99mm. A little tighter, but still about double what it should be.

Post by **rolsen11** » 21 Jul 2025, 14:05

I got the zip ties installed, the gap ended up becoming tighter than anticipated at 0.15-0.2 mm. The clutch is not touching the clutch plate though and the clutch is now operating as it should be. AC blows nice and cold and most importantly, it stays that way. Thanks abscate!

Post by **scot850** » 21 Jul 2025, 14:44

Well done!

Neil.