Avensis Remote Problem

[Q.S.]

Avensis 2002

Remote key Valeo 433.92Mhz HM426/2000

2 button remote

My key stopped working on the remote today, the led did not light when the button(s) were pressed.

First thoughts were dead Battery although it wasn't that old but when a new Battery is fitted (or the old one replaced) the led flashes for some time, if near the car at the time the car usually unlocks and locks keep klunking intermittently.

Unlock switch was a bit dodgy on its solder joints so resoldered it (switch seems to work according to continuity tester set at 200 ohms)

Still the same.

Anyone got any ideas why this is happening?

Could try a couple of new microswitches or buy a second hand key for its transmitter but thought I'd sound it out first.

Thanks in anticipation.

[junebug1701]

Avensis 2002

Remote key Valeo 433.92Mhz HM426/2000

2 button remote

My key stopped working on the remote today, the led did not light when the button(s) were pressed.

First thoughts were dead battery although it wasn't that old but when a new battery is fitted (or the old one replaced) the led flashes for some time, if near the car at the time the car usually unlocks and locks keep klunking intermittently.

Unlock switch was a bit dodgy on its solder joints so resoldered it (switch seems to work according to continuity tester set at 200 ohms)

Still the same.

Anyone got any ideas why this is happening?

Could try a couple of new microswitches or buy a second hand key for its transmitter but thought I'd sound it out first.

Thanks in anticipation.

My guess is that one of the microswitches is sticking on and draining the Battery. Or a bad solder job could have shorted the circuit out. If you can find a replacement module for a good price I would swap it out.

[Q.S.]

Avensis 2002

Remote key Valeo 433.92Mhz HM426/2000

2 button remote

My key stopped working on the remote today, the led did not light when the button(s) were pressed.

First thoughts were dead battery although it wasn't that old but when a new battery is fitted (or the old one replaced) the led flashes for some time, if near the car at the time the car usually unlocks and locks keep klunking intermittently.

Unlock switch was a bit dodgy on its solder joints so resoldered it (switch seems to work according to continuity tester set at 200 ohms)

Still the same.

Anyone got any ideas why this is happening?

Could try a couple of new microswitches or buy a second hand key for its transmitter but thought I'd sound it out first.

Thanks in anticipation.

My guess is that one of the microswitches is sticking on and draining the Battery. Or a bad solder job could have shorted the circuit out. If you can find a replacement module for a good price I would swap it out.

Checked both microswitches, they both switch off and on. Had the circuit board under the magnifier and can't see any solder problems (apart from the one I found earlier on the open switch and resoldered). Looking to get hold of a second hand key, will then use the blade and transponder chip from this key and the transmitter from the second hand one (reprogram for the locks).

[Q.S.]

In case anyone is interested, I think I have found the problem. Removed the switches from the circuit board and connected back up to the Battery holder and Hey Presto, no flashing from the led. Bridge out the switch connections manually and the remote works. On close inspection under the magnifier, the underside of one of the switches was coated in a sticky substance. Cleaned off the switches and the circuit board with electrical cleaner and refitted switches and all works. Going to fit some new switches and buttons while I have it in bits and hopefully, that will be that. Can only presume that there was a minute current flowing through the sticky crud that was on the switch base.

Thanks for your thoughts on the matter junebug1701.

[t-spiritpete]

In case anyone is interested, I think I have found the problem. Removed the switches from the circuit board and connected back up to the battery holder and Hey Presto, no flashing from the led. Bridge out the switch connections manually and the remote works. On close inspection under the magnifier, the underside of one of the switches was coated in a sticky substance. Cleaned off the switches and the circuit board with electrical cleaner and refitted switches and all works. Going to fit some new switches and buttons while I have it in bits and hopefully, that will be that. Can only presume that there was a minute current flowing through the sticky crud that was on the switch base.

Thanks for your thoughts on the matter junebug1701.

Hi mate that's a really great result due your perseverance.

Regards ...... Pete.

[Q.S.]

I can do a lot of persevering for the £150 that Mr T. quoted for a new key

[t-spiritpete]

I can do a lot of persevering for the £150 that Mr T. quoted for a new key

Cheers mate ..... a man after my own heart then .... Ooooooooooh yes!;)

[junebug1701]

In case anyone is interested, I think I have found the problem. Removed the switches from the circuit board and connected back up to the battery holder and Hey Presto, no flashing from the led. Bridge out the switch connections manually and the remote works. On close inspection under the magnifier, the underside of one of the switches was coated in a sticky substance. Cleaned off the switches and the circuit board with electrical cleaner and refitted switches and all works. Going to fit some new switches and buttons while I have it in bits and hopefully, that will be that. Can only presume that there was a minute current flowing through the sticky crud that was on the switch base.

Thanks for your thoughts on the matter junebug1701.

Glad to hear you got it sorted! I've seen the same problem with TV remotes. I don't know where that crud comes from.

[Thermal]

Anyone got any ideas why this is happening?

Just for info, that "crud" is the result of a chemical reaction, when vapor from a leaking coin cell reacts over time with an over-generously applied layer of lacquer on the circuit board and corrodes what's under it.

Removing the conducting build-up and carefully cleaning the board, like you did, may fix the problem.