S90, 1998, Flashing Blue AC Light

rfisk · Post by **rfisk** » 30 May 2012, 11:06

Mileage: 155,200
The blue light which surrounds the AC button flashes all the time, even when the AC is off. It is a continuous flash, it is not flashing out a code. There are no computer codes. When I turn on the AC it only sorta works. It won't keep up with an Arizona summer.
This started happening right after I had the timinig belt replaced.

Post by **JDS60R** » 30 May 2012, 11:34

Welcome to Matthews Volvo site !!!
Please let us know if you have any questions.

Post by **billofdurham** » 30 May 2012, 12:32

The flashing AC light is indicating a fault in the AC system. It has its own self-diagnostic function which does not need a code reader.

The attached shows how to use it. Ignore the heading "1997 Volvo 960" as it also applies to the S/V90.

960 AC diagnostics.pdf: (684.14 KiB) Downloaded 2340 times

Bill.

rfisk · Post by **rfisk** » 01 Jun 2012, 20:49

Hi Bill,
No matter how hard we tried, we could not get the ECC to enter self-diagnosis mode, therefore no code. The blue light kept flashing continuously. Then my mechanic started measuring pressures. He thinks that the compressor is starting to fail. He charged it with more coolant and said he'll give me a quote for a new compressor on Monday.

Rick

: My ECC controls

Post by **jimmy57** » 01 Jun 2012, 22:53

The ECC diagnostics detects problems with: in car sensor in dome lamp, ambient sensor in blower case next to blower, the electric solenoid array, the temp control servo motor, and the blower power stage. The diagnostics has no relation to the compressor or refrigerant level.
For diagnostic display the a/c button has to be off, which mean lit red on your 98, before the button is depressed to get the code display to start.

rfisk · Post by **rfisk** » 02 Jun 2012, 11:25

Hi Jimmy,
My problem is entering the ECC diagnostic mode.
I put the car outside with direct sun on the dash, therefore on the solar sensor. With the engine running, I then put the blower fan control in AUTO, the function selector in VENT and the temperature knob to MAXIMUM COOLING.
I start with the AC and RECIRC buttons off and then, within 5 seconds, I turn on the RECIRC button on followed by turning on and then turning off the AC button.
As I read it this should put the ECC in diagnostic mode. It doesn't so, what am I doing wrong.

Rick

Post by **billofdurham** » 02 Jun 2012, 12:00

You are turning off the AC. After depressing the Recirc button depress and release the AC button within 5 seconds. Self diagnostics should now start.

Bill.

Post by **jimmy57** » 02 Jun 2012, 12:54

Just as Bill said. BE sure your snowflake is red then you depress and depress again so it ends up being red.

Wait a minute! Your a/c button is blue? If so your ECC panel has been replaced with an older one. Not that it will not work just the a/c button strategy is different.
If blue button then start with it not lit, depress and depress again and will be unlit when before it begins to blink the codes.

EDIT: I can't get my 95 960 to display codes. It has the A/C OFF labeled button and I tried it with it lit and unlit and I tried putting the knobs in the positions just before asking for code display.
????????????????

rfisk · Post by **rfisk** » 03 Jun 2012, 03:57

Hi Bill,
It worked! Diagnostic mode was entered. It flashed "2-1-4." That's the servo. I'll show my mechanic on Monday. I pray it's not buried too far in the dash.

Rick

Post by **billofdurham** » 03 Jun 2012, 12:22

The attached might help your mechanic to find it. In the inset picture it is marked with a red X.

S90 heater servomotor location.pdf: (291.69 KiB) Downloaded 852 times

Bill.