Odd electrical faults

[alistairolsen]

Hi everyone,

I have some strange faults on my 2002 172 ph2 which may or may not be related, so bundling them here for advice

1) My alternator exciter wire is live all the time, I posted about this previously [here] and haven't found the fault, I've simply left it unplugged meantime and the alternator self excites fine.

2) I have the common immobiliser fault where the car doesn't recognise the key, solved by leaving the key in the ignition turned on for a while. This is relatively infrequent, probably once a month (the car isn't used often). I don't know if it's linked to leaving the car unlocked, or locking and unlocking it multiple times between starts (rural, infrequently used car)

3) Every second start or thereabouts I get a light

 

[alistairolsen]

Edit: Who knew there was a time limit on editing posts? Not me. Could a kind admin overwrite the first post for me?

Hi everyone,

I have some strange faults on my 2002 172 ph2 which may or may not be related, so bundling them here for advice

1) My alternator exciter wire is live all the time, I posted about this previously [https://cliosport.net/threads/ph2-172-alternator-exciter-live-with-ignition-off.847359/] and haven't found the fault, I've simply left it unplugged meantime and the alternator self excites fine. Thanks to Barnesautos for the advice, it may be coming time to pull the dash.

2) I have the common immobiliser fault where the car doesn't recognise the key (round red light), solved by leaving the key in the ignition turned on for a while. This is relatively infrequent, probably once a month (the car isn't used often). I don't know if it's linked to leaving the car unlocked, or locking and unlocking it multiple times between starts (rural, infrequently used car)

3) Every second start or thereabouts I get a light (which relates to the fly by wire throttle I believe) which comes on with the ignition and doesn't go out. If I cycle the ignition sometimes it'll go away and then start normally. If I start the car with the light on it take a few turns (like a cam sensor failure) and then starts with a 2krpm idle and no reaction to the throttle pedal. Turning it off and back on clears it and it drives perfectly normally with no hesitation or anything leading me to believe its more of a 'handshake' issue than a faulty pedal or throttle body

4) Every now and then I get this, with the STOP light flashing and the car will not start. It doesn't clear like the immobiliser fault. It has always (so far) gone away after many many cycles of the ignition, or leaving it for a while, or locking the doors - I've yet to figure out if there is a pattern but it's only a matter of time until I end up stuck somewhere.
View attachment 1675643

It seems unlikely to me that these are all independent faults, so either a dash fault perhaps, or a loom issue - does anyone have any good ideas where to look before I have to pull the whole car apart chasing issues? Once started the car drives faultlessly so there's nothing mechanical or permanent wrong I don't think.

Thanks!

 

[youngarthur]

Not all, but a lot of these strange problems are because of a bad/loose earth fault. Another common problem is Battery voltage, eliminate these problems first.Find someone with a clip/ diagnostic tool in your area, do not start throwing money at it.

 

[alistairolsen]

Not all, but a lot of these strange problems are because of a bad/loose earth fault. Another common problem is Battery voltage, eliminate these problems first.Find someone with a clip/ diagnostic tool in your area, do not start throwing money at it.

Yeah agreed!

Battery voltage is good, and I've tried it with a battery charger connected to elevate it a little too.

Main earths are also good (battery to body is new, gearbox to body was cleaned up when the box was out for a recent clutch, Main engine loom to body shares a post with the battery to body point and I've been through and checked them all today) so I guess next is to find out where the cluster/UCH earths are.

On a sidenote, if the engine earth was poor I'd expect to see lots of engine sensor faults and there's nothing stored at all.

I don't know anyone with Clip, I've had a poke with the limited access a Bluetooth diagnostic tool gives you