Hello-

I'm new to the forum... I've been a member for a while but I've only really used this to learn from what has already been posted. I have a 1992 Volvo 960 24 Valve inline 6. It has 125K miles on it, and is an awesome vehicle. It is exactly what I wanted, and hasn't let me down!

About a month ago the check engine light came on. I used the OBD:

Position A1: 1-1-1
Position A2: 5-1-2 (see photo below)
Position A3: Nothing
Position B1: 1-1-1
Position B2: 1-2-2 (see photos below)
Position B6: Nothing

I know that 1-1-1 mean "all clear" but I am not familiar with getting "nothing" by which I mean not any blinking lights.

Also with the key in position II to check the OBD I noticed a constant humming (sounded like a bee) as if lot of current were going through a Bosch part between the air mass sensor and the engine. I looked up the part number (Bosch 0 280 140 522) and found that it was the Idle Control Valve. (Photo below)

I disconnected to get a better look, this made the humming stop, because it had no current, then when I plugged it in again the humming did not continue. I put the key back to position I, then back to position II and the humming came back. Here is a link: 84 1984 Volvo 244 Idle Control Valve - Fuel Injection - Bosch - PartsGeek

Three questions:
What do the codes mean?
What should I do to fix the codes?
Is it normal for the idle control valve to hum like that?

Thank you!

 

According to this website: www.volvoclub.org.uk/faq/EngineOBDCodes.html

The A2 socket is for fuel injection, but there is no 5-1-2 code.
The B2 socket is for cruise control, but there is no 1-2-2 code.

According to this website:www.troublecodes.net/Volvo/

1-2-2 Air temp sensor signal.
5-1-2 Oxygen integrator at max lean running limit.

Does this forum have another site, or de-coding guide for a 1992 24 valve 960?

 

Does anyone have any advice on this?

Thanks!

Tyler

 

Yep. I have posted my online manuals a few times here:

A2/512: Short Term Fuel Trim Lower Limit
B2/122: Speed has not exceeded 35 km/h or no vehicle speed sensor signal

 

I also am trying to resolve a code 512 on my 95 960 w/obd l. Henry could post your link to you diagnostics.

My code came following replacing my maf that failed.

I appreciate your help.

Dave

 

https://docs.google.com/open?id=0B6p...M2M2YxZDRhZTVk

 

Code A2/512 points to excessive back-pressure, i.e. clogged cat.