Hi,
I've bought a 172 and the dashboard warning light suggests that one of the four switched doors/boot/bonnet is open. I was led to believe it was a switch problem but I don't think that it is. The real issue is that when I lock the car it just makes a continuous whiney beep from the engine bay so I end up leaving it unlocked.
I have done some checks as follows that have not cleared the fault:
Both passenger door and drivers door - both switches are normally closed, so when the door shuts they go open circuit. they both work so to my mind removing the switch from the door for continued diagnostics leaves the car in the door closed state. I have continuity tested each green wire from the door switch harness to pin 40 on the green plug of the UCH. I guess the theory is when the doors open it applies earth to pin 40 which would happen had I not removed both door switches just now. so it seems the door switches may be ok.
Boot switch - from what I can see there is only one switch on the boot that would operate both the dash warning light and also the boot courtesy lamp. with the boot open the courtesy lamp comes on, when I disconnect the plug coupler the tailgate switch the courtesy lamp turns off, which suggests to me that this circuit is ok. I'm not sure if this can operate seemingly as well as it is and there still be some other wiring fault present further upstream towards the UCH that would cause the dash warning light to operate, I doubt it so I think this circuit is all ok too?
Bonnet switch - again this is a normally closed switch, so when the bonnet is closed this switch goes open circuit. so to my thinking if it were to be removed this would leave the circuit open, which is the state it needs to be in to think that the bonnet is closed. however doing further proving on this switch is the problem. I cannot find any clio wiring diagram that included bonnet switch wiring, only doors and tailgate. additionally both the A&B terminals of the bonnet switch loom plug coupler are <1 ohm to the chassis. I would have expected to find this condition on only one leg of the circuit? the only thing I haven't done is check if this is the same with all the connectors off of the UCH. I cant help but think this wiring and not the switch might be an issue, or even worse a problem in the control circuit board.
does anyone have any ideas? or maybe a wiring diagram showing how the bonnet switch circuit works?
alternatively I'm not bothered about the alarm working but i'd like to be able to lose the dash warning light and have the central locking work without making a long beep so if there's a frig to bypass this that would be handy.......
Thanks
I've bought a 172 and the dashboard warning light suggests that one of the four switched doors/boot/bonnet is open. I was led to believe it was a switch problem but I don't think that it is. The real issue is that when I lock the car it just makes a continuous whiney beep from the engine bay so I end up leaving it unlocked.
I have done some checks as follows that have not cleared the fault:
Both passenger door and drivers door - both switches are normally closed, so when the door shuts they go open circuit. they both work so to my mind removing the switch from the door for continued diagnostics leaves the car in the door closed state. I have continuity tested each green wire from the door switch harness to pin 40 on the green plug of the UCH. I guess the theory is when the doors open it applies earth to pin 40 which would happen had I not removed both door switches just now. so it seems the door switches may be ok.
Boot switch - from what I can see there is only one switch on the boot that would operate both the dash warning light and also the boot courtesy lamp. with the boot open the courtesy lamp comes on, when I disconnect the plug coupler the tailgate switch the courtesy lamp turns off, which suggests to me that this circuit is ok. I'm not sure if this can operate seemingly as well as it is and there still be some other wiring fault present further upstream towards the UCH that would cause the dash warning light to operate, I doubt it so I think this circuit is all ok too?
Bonnet switch - again this is a normally closed switch, so when the bonnet is closed this switch goes open circuit. so to my thinking if it were to be removed this would leave the circuit open, which is the state it needs to be in to think that the bonnet is closed. however doing further proving on this switch is the problem. I cannot find any clio wiring diagram that included bonnet switch wiring, only doors and tailgate. additionally both the A&B terminals of the bonnet switch loom plug coupler are <1 ohm to the chassis. I would have expected to find this condition on only one leg of the circuit? the only thing I haven't done is check if this is the same with all the connectors off of the UCH. I cant help but think this wiring and not the switch might be an issue, or even worse a problem in the control circuit board.
does anyone have any ideas? or maybe a wiring diagram showing how the bonnet switch circuit works?
alternatively I'm not bothered about the alarm working but i'd like to be able to lose the dash warning light and have the central locking work without making a long beep so if there's a frig to bypass this that would be handy.......
Thanks
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