1996 855 T5 - Can't reset service light

[Sommerfeldt]

So, I've been putting it off, but I built myself a new flashing LED code reader again, and read out the codes to see what the CTL was all about.
As expected, it was a bad signal from the MAF, which is slowly taking its leave of this world. Clearing codes from ECU and ECC was no problem - cleared and returned 1-1-1 on second read.

On the heels of that, I wanted to reset my Service reminder light. I've never tried that before, but figured it couldn't be that hard... turns out I was wrong.
I connected pin 5 to - and switch, pin 3 to - and 16 to +, then the tried pressing switch 4 times, and waited for input light to give it the 1-5-1 code. Didn't show up. Tried pressing switch 4 times again, and got a strange reaction - LED flashed 4 times, then went dark for a good while (longer than normal pause between numbers, for example). Then flashed 4 times again - I've never seen or read about that reaction before, so I took the safe route and just turned the ignition off (engine wasn't running, of course).

So... what's going on? Has anyone seen this? I can't find any info on the reaction either here, on jonesrh, or any other forum.

As a fun fact, I went down to my local Volvo dealer, to get a price on a new MAF... they want 523,70 USD for a new Bosch unit, by today's exchange rate. The mechanic I talked to was pretty impressed by the flashing LED code reader, however, so I pointed him here for more info and the best DIY Volvo community.


- S

[misha]

Being a '96 your car is obdII and being a T5 it have Motronic 4.3 management which still produce flash codes along with ecc unit.
For clearing service light reminder on '96 and after you will need at least vol-fcr scan tool.

About Maf....Since you are in EU go directly with Bosch dealership & service.It's around 200-250€.
"Stealerships" prices for the same Bosch Maf are about that range of 500$.

[polskamafia mjl]

+1

Go to dealer to reset Service light. Avoid dealer for new MAF.

[Sommerfeldt]

Thanks, guys.
I always try to avoid mechanics and dealerships, since I both like to do stuff myself, and hate paying too much to do too little...

I read up on the flashing LED tool stuff, and thought that inputting the same commands through my OBDII-port on pin 3 as on the under-the-hood boxes would produce the same result. Guess not though. Dealership it is.

- S

[rspi]

I use this:

[Sommerfeldt]

Thanks, Robert! I'll check that out. Wasn't too bad a price, but shipping over this here might be more than the tool itself...

- S