A/C control panel flickering, heater starts only after ~5min

S40 Phil · Oct 22nd, 2018, 13:47

My heater doesn't work when cold (this night, it was freezing).

The first time, nothing lights up. After some time, the LEDs on the A/C- and circulating air buttons flicker. After a couple of minutes (~4-5 km drive), the blower, air condition and rear window heating work without any problem.

I have Vol FCR and Brick diag but some times, they struggle to read out the errors and cannot identify the module. Is there any other (free) diag software recommended?

What I already found some times (does not show up every time, probably transient errors):

ECC-212 Temperature Motor Position sensor, SC to to battery
ECC-222 Air distribution motor position sensor, SC to battery
ECC-322 Air distribution motor, OC or active too long
ECC-412 Blower fan motor, SC to ground in signal cable

In the ECU (not the A/C-control unit) is some times the
ECC-342 air conditioning (A/C) relay signal faulty

Has anybody here the secret hint?

If warm, everything works great indeed!

Is that A/C relay probably located in the engine compartment and warms up after cold start?

It's a 1998 S40 T4.

gatos · Oct 22nd, 2018, 18:59

My brothers 2004 V40 had a similar problem a few years ago. When starting the car, the heater control panel would not work at all. No lights, no LED, no controls, nothing. After a couple of minutes driving, the heater control panel would come alive and work perfectly fine. In this case, it was a relay under the driver's footwell that was faulty. Replaced and problem was gone for good

S40 Phil · Oct 22nd, 2018, 22:00

Thanks for your information.

I guess your brother had a RHD Volvo?

Mine is LHD, so it should be that device?
https://www.youtube.com/watch?v=U2_67xPkyW0

Or is there a true relay next to the fusebox?
One of those in 11B?
2005-volvo-s40-engine-diagram-2000-volvo-s40-fuse-box-free-download-wiring-diagrams-schematics[2.jpg

I checked the A/C-relay in the engine compartment but there seems to be everything OK.

S40 Phil · Nov 7th, 2018, 21:32

Some days ago, I replaced the left upper relay above the fuses (picture 11/B). Quite hard to get there.

I just installed a universal relay (normally open) and until now, it works great.

Are there specific requirements (e.g. integrated surge diode) for the relay? I only measured the current the coil consumes. The factory installed one read 0.15 A and my "new" (in fact it's about 30 years old...) one 0.14 A.

Oct 22nd, 2018, 13:47	#1
S40 Phil New Member Last Online: Jan 28th, 2019 18:47 Join Date: Oct 2018 Location: AG	A/C control panel flickering, heater starts only after ~5min My heater doesn't work when cold (this night, it was freezing). The first time, nothing lights up. After some time, the LEDs on the A/C- and circulating air buttons flicker. After a couple of minutes (~4-5 km drive), the blower, air condition and rear window heating work without any problem. I have Vol FCR and Brick diag but some times, they struggle to read out the errors and cannot identify the module. Is there any other (free) diag software recommended? What I already found some times (does not show up every time, probably transient errors): ECC-212 Temperature Motor Position sensor, SC to to battery ECC-222 Air distribution motor position sensor, SC to battery ECC-322 Air distribution motor, OC or active too long ECC-412 Blower fan motor, SC to ground in signal cable In the ECU (not the A/C-control unit) is some times the ECC-342 air conditioning (A/C) relay signal faulty Has anybody here the secret hint? If warm, everything works great indeed! Is that A/C relay probably located in the engine compartment and warms up after cold start? It's a 1998 S40 T4. Last edited by S40 Phil; Oct 22nd, 2018 at 13:50.

Oct 22nd, 2018, 18:59	#2
gatos Premier Member Last Online: Nov 15th, 2022 21:34 Join Date: Apr 2010 Location: London / Essex	My brothers 2004 V40 had a similar problem a few years ago. When starting the car, the heater control panel would not work at all. No lights, no LED, no controls, nothing. After a couple of minutes driving, the heater control panel would come alive and work perfectly fine. In this case, it was a relay under the driver's footwell that was faulty. Replaced and problem was gone for good __________________ Current car: 2002 S40 1.9D, 1992 240SE Nullius in Verba

Oct 22nd, 2018, 22:00	#3
S40 Phil New Member Last Online: Jan 28th, 2019 18:47 Join Date: Oct 2018 Location: AG	Thanks for your information. I guess your brother had a RHD Volvo? Mine is LHD, so it should be that device? https://www.youtube.com/watch?v=U2_67xPkyW0 Or is there a true relay next to the fusebox? One of those in 11B? 2005-volvo-s40-engine-diagram-2000-volvo-s40-fuse-box-free-download-wiring-diagrams-schematics[2.jpg I checked the A/C-relay in the engine compartment but there seems to be everything OK. Last edited by S40 Phil; Oct 22nd, 2018 at 22:03.

Nov 7th, 2018, 21:32	#4
S40 Phil New Member Last Online: Jan 28th, 2019 18:47 Join Date: Oct 2018 Location: AG	Some days ago, I replaced the left upper relay above the fuses (picture 11/B). Quite hard to get there. I just installed a universal relay (normally open) and until now, it works great. Are there specific requirements (e.g. integrated surge diode) for the relay? I only measured the current the coil consumes. The factory installed one read 0.15 A and my "new" (in fact it's about 30 years old...) one 0.14 A.

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