2002 V70 keys vs washing mashine

Post by **vtl** » 21 Nov 2014, 22:19

So it finally happened: the only set of key+remote spent an hour in washing machine...

Megamos chip in ignition key was not damaged, and the car starts. But the remote died. I took it apart, cleaned with isopropyl alcohol, touched all contacts with soldering iron, replaced battery - no luck. There was another remote fob, which I bought used on ebay, I tried to swap HCS412 chip - remote still doesn't work. The schematics is pretty simple, nothing can be damaged too bad by water. The only thing to go south is this transponder chip, which probably had DATA pin pulled up through soapy water and that erased EEPROM.

So, what are my options? The car is old, it still drives, I don't want to spend two or three hundreds on a new remote. Can the dealer reprogram a used remote? Or it needs fresh one? If latter is the case, will it suffice to just erase EEPROM or, maybe, replace the chip, which costs like $50 for 500 pcs on alibaba and that is still cheaper than paying almost $100 for the whole new remote.

Post by **precopster** » 21 Nov 2014, 22:42

If you have a Dice contact MVS user doublebug. He can program a new/used remote I believe. Check this with him. Cheers Mike

draser · Post by **draser** » 22 Nov 2014, 21:09

Is there any inductance (coil) on that pcb, can you post a pic of the pcb? Coil may be in the pcb, but if it's not any moisture left in there or soap will shift the transmitter frequency.

Post by **vtl** » 22 Nov 2014, 21:21

precopster wrote:If you have a Dice contact MVS user doublebug. He can program a new/used remote I believe. Check this with him. Cheers Mike

Thanks, precopster! I do have DiCE, but LCD lamp in my laptop died just couple of days ago, I have to sort that out first. And, I guess, he'd want a remote access, so I need to route cat-5 cable into garage or place wifi spot somewhere close.

Post by **vtl** » 22 Nov 2014, 21:24

draser wrote:Is there any inductance (coil) on that pcb, can you post a pic of the pcb? Coil may be in the pcb, but if it's not any moisture left in there or soap will shift the transmitter frequency.

Nah, I resoldered chip to a good PCB. I think it has EEPROM erased, 'cause HCS412 datasheet makes a stress on a careful work with DATA pin.

draser · Post by **draser** » 23 Nov 2014, 07:49

Understood. Is that metalic square I see there a shielded coil? If it is, I bet there's moisture in there. On the bathed pcb I mean. It kinda hard to erase an eeprom. Are the switches resistive or capacitive? If you ohm meter the contact and push resistance is zero?

speedyt5 · Post by **speedyt5** » 23 Nov 2014, 10:09

I got my remote programmed at the dealer for 100 dollars. I bought it off eBay. However mine is. 99 s70, not sure if that matters.

Post by **vtl** » 23 Nov 2014, 11:11

draser wrote:Understood. Is that metalic square I see there a shielded coil? If it is, I bet there's moisture in there. On the bathed pcb I mean. It kinda hard to erase an eeprom. Are the switches resistive or capacitive? If you ohm meter the contact and push resistance is zero?

Metallic square is RF transmitter, I think.

I took HCS chip from my pcb and soldered to another pcb, which was not damaged. So it's really irrelevant if anything else on my pcb is broken

Post by **vtl** » 23 Nov 2014, 11:12

speedyt5 wrote:I got my remote programmed at the dealer for 100 dollars. I bought it off eBay. However mine is. 99 s70, not sure if that matters.

Yeah, hundred bucks... Plus a new remote... I'm talking to doublebag

draser · Post by **draser** » 23 Nov 2014, 11:42

True, provided the carrier frequency is the same for all cars.