Clearing Codes that Come Right Back

[KidsV70]

FWIW, I had no luck with #2 on my '02 V70. Back when I didn't know enough about these cars, I tried a DIM from a 2003 or 2004 S60 (looked identical) in mine and got no response. The DIM wouldn't even light up, so I went back to my original, which turned out to be ok. (FYI- I still don't know as much as I need, but I know more than I did!! )

If you are handy with electronics, you can test the LED with a VOM that has the right settings. Look for the diode setting. You can test the SRS light diode against the others that make up the warning light cluster, or check online for the right specifications. I don't recall it right now, sorry.

Good Luck!

[precopster]

SRS module is the most likely suspect for me here. If the SRS LED light circuit in the DIM were faulty it would not light up. In this case the SRS module fails to detect the SRS light circuit and pulls up the code you see.

[SuperHerman]

It would be great if you had VIDA to do the testing. See this similar post: viewtopic.php?f=9&t=88497. It would keep things focused in the "Volvo world" as well as provide the correct information.

Here you had no accidents and an out of the blue SRS module seems odd. The codes you posted, per Rick's post, point to the DIM. But, what precopster says make sense regarding the LED and is what I was thinking.

Do you still have that DIM you mentioned? Although DIMs are the same part number, what is critical is the software loaded. Usually, discounting updates, which at this age of the car's life, have generally been all updated. So the difference in seemingly identical DIMS is the loaded software. That is why you shoot for like for like swaps. As the linked post shows, a swap for a used like for like part many times is the cheapest approach.

[Mrfiacus]

Wow! Some much information. My head is spinning. A bit. LOL. I do have the DIM part number — 8637995. I have been scouring eBay looking for a replacement. I think this might be the route I go.
Thanks you guys — I’m thankful and impressed!

[Mrfiacus]

Oh, and yes, I still have the part.

[SuperHerman]

Read the other post I listed and contact Yeager - maybe he can get the other part you still have to work.

[EngineeringBloke]

SRS does not light

The SRS light turns on during engine start. If too much power (a short circuit that might exclude the LED so it would not light), or too little power (not enough to light the LED), is detected then the SRS display is considered failed. A CEL is lit, a message displayed and a code stored.

Battery reconnection - SRS light stuck on

This is different than reconnecting the battery with the key is other than position 2. Position 2 provides a load and reduces surging. Otherwise, the SRS light can get set on and only reset by the dealer, but this is not your current issue.

DIM circuit with LED indicators

Almost certainly the failure is between the integrated circuit and the display LEDs on the DIM, and NOT involving the SRS module itself. You can see the back of the circuit in this video at 1:09 (LED connections are lower left). He flips over the DIM and you can see the front side with the LEDs (square boxes with a center disk) at 1:58. You can also see the ribbon connector that connects the LEDs to the driver circuits. You could check the resistance to look for odd values on the SRS part of the circuit, but this is all undocumented. The failure could be in either of the two main DIM boards here (or the ribbon cable).



Car cannot let you know if it detects that airbag system has failed

The reason this is serious is that the car can no longer signal to you if it detects the SRS cannot be activated. The risk is that the SRS fails and in a crash cannot activate the airbags.

The LED lights in the DIM are reliable but the related components can fail. I am sure you have seen car brake lights with multiple LEDs out (due to wiring and not to multiple LED failures).

The DIM could be repaired. It might be the soldered joints on an integrated circuit, or the wires jumping from the main DIM circuit board to the LED display section (and the fuel gauge) but I suspect it will be hard to track down.

[shiloh51933]

Clearing any diagnostic trouble code doesn't resolve the issue and believe me when I say that I wish it was this easy.