freemansteve

spray one bush at a time with silicone and see which causes the noise to away. don't forget subframe bushes as well as dampers and spring ends.

"so on Citigo the side light setting is just the DRL for the front of the car? " No! As a said, the "sidelight setting" on the lighting switch will turn on the rear lights as well as the DRLs at the front. If the lighting switch is off, the front DRLs are on, fully bright, but with no tail lights. It's probably easiest to test all the combinations of the light switch with ignition on and off, walking round the car to see. Don't forget to test the indicator position too, because if you are parked and have "sidelights" set on the switch (dim DRLs and tail lights on) the indicator stalk will set only left or right parking lights. The logic is perfectly good when you see it in action.

Instrument panel lights are on all the time the ignition is on, dimly if ambient light level is high enough, brightly if your lights are turned on, but OFF if your lights are off and ambient light is below a certain level (it's a warning to turn your lights on) And obviously DRLs go to half-brightness (by law) when your headlights are turned on, and also when sidelights are on but only when parked (ignition off)

And the reluctor ring is in the hub assembly (the bit where you poked your new sensor in). Seriously, you need a proper garage.

Battery disconnect is like a "cold boot" on a PC and resets some things. A long shot though. Try that, then drive the car... How old is the battery? Said before, but dying batteries often can start cars, but still not have enough volts (not current!) to ensure electronics are OK - weird, but true....

yes cable damage is a possibility - if the sensor is (as I think) chip-based, it's hard to say if 2V is meaningful; the cable to the ABS unit is at least not open-circuit... I think the reluctor ring can get clogged or corrode, but you'll have to be up for disassembly of the rear hub and drum brake. If you cannot remove the RHS rear wheel, I suspect you may not have the tools to do a hub disassembly, but any decent independent garage will be able to. I assume you have you disconnected and reconnected the battery for a reset, and driven the car 1/2 mile, in case the new sensor needs to be recognized by the system - I don't know whether you have to reset error codes, but probably, so check this first with a garage. For tech help, the Up Owners Club has far more members and quite a few genuine tech people on it..... The Up is the same car as a Citigo.

best place for it (well, electronic recycling, not landfill obviously)

What state is the reluctor ring in? Voltages won't tell you much. There are no locknuts for the wheels, only bolts (4).

It's pretty hard to see how "jolts" and potholes would damage an ABS sensor directly.... The most likely problem is that the ABS sensor on these cars is they use a chip-based Hall sensor that has failed, possibly by water ingress. Or the reluctor ring is clogged with road gunge that reduces the signal level. The reluctor ring on these cars is toothed ("castellated" if you prefer), and not magnetic. There is a magnetic element in the sensor that creates a signal whose amplitude varies according to the metal mass passing under it - analogous to an electric guitar string and a guitar pickup (n.b. the moving string is not magnetized, it just alters the field in the pickup).

Is it a chihuahua that you put under the false floor?

I've heard that a battery affects ABS sensors. A duff battery can play havoc with electronics, but your issue seems to be a specific, consistent and isolated fault. Although some ABS sensors are "coil on magnet" types, like a guitar pickup, I think most modern ones use Hall sensors, and these are usually just an IC (no coils).

The (rotating) reluctor ring might be a problem, but I bet it's the sensor.

Open means either one or more conductors has gone open circuit, i.e. is no longer connected to the ABS controller, maybe cut. Short to Ground means a wire that should have a signal is connecting to the chassis, or some to metal, possibly trapped or stripped insulation. If you buy a sensor and try it, you won't be able to return it. No point in a multimeter unless you know where the wires start and terminate for checking continuity. You may be able to check if the sensor internally shorted or open circuit. "Left rear" is on the left from the point of view of your left when sitting in the car. Chances are it's a faulty sensor. Buy one from an internet shop.

I can't recall, but the topic has been well covered here: (if you search) There were 2 side pieces that supported a floor, all easy to bolt on, IIRC. https://www.upownersclub.co.uk

The cradle that sits on the 'port' on top of the dash is removable, but it looks different to my F/L version, so I'm not sure how it unclips....

Glad it works now! Steer clear of acetone next time - it can destroy some plastics and ruin paint. Besides, isopropyl is cheap.

Any garage can fix this in under an hour, assuming the sensor needs changing (£25?). Could the connector as said.

You probably have cables or something bunched up behind it

Only some versions of F/L Citigo's have twin lamp units. Possible SE-L only? I don't know, but it's a standard F/L thing across the board..

Two pairs of H7's. Takes 5 mins to change. Lots of brighter choices, but the brighter they are, the quicker they die.

AFAIK no Up/Citigo/Mii ever had silicon bags in the header tank (per UpOwner's Club).

Always make sure contact pins are clean, using cotton bud & isopropyl. It may not be your issue, but it's a known problem.

How does nitrogen affect TPS monitoring (which is done using the ABS sensors)?

If ambient light is below a certain level, the dash illumination - which is normally always on - turns off to remind you to put your headlights on. If your car has DRLs, these are always on, but at half brightness if the headlights are on or if you are parked up an on sidelights. When driving, turning sidelights on simply tuns on the tail lights. There are obviously many driving conditions where bright DRLs and tail lights are fine (sidelights) so that you are visible.

Clean the contact pins with a cotton bud and isopropyl.