Yaris 1.4 D-4D 2003 Rear fog lamp

[chocolatekay]

Dear All,

My Yaris has unexpectedly failed its MOT on two parts:

1. License plate lamp
2. Rear fog lamp

I believe the former is easy to fix and will be ordering 501 bulbs to replace and hopefully this will do the trick.

The rear fog lamps are a concern as there is little information available on how to diagnose this fault. I am also unable to confirm the bulb for the rear fog lamp - I have come up with 582, 308 and 382!

I would greatly appreciate the help of this forum to get these two issues sorted and get my MOT passed.

Thank you in advance!

Kay :)

[shepd]

The typical way to diagnose a faulty bulb on any vehicle is to first get access to the bulb itself, then remove the bulb. Place a meter across the terminals of the bulb, set the meter to ohms, and see what the result is. Dead short means the bulb is shorted (and you may have an open fuse at this point), any low reading means the bulb should be good, and infinity means your bulb is burned out and needs to be replaced.

You can then turn your meter to volts and probe the socket. If the meter reads 12 volts (or so) when you activate the light, and no voltage when you deactivate the light, your wiring, fuse, and switch are good. If not, inspect the fuse first (remove it, if it measures 0 ohms it's good, otherwise, replace it and see if the replacement blows immediately--if so suspect the wiring or switch).

After that, you'd have the switch or wiring left. But I imagine they'd have told you if those were bad.

Anyways, while the bulb is out, if it's at fault, just bring it to a store and they'll match it for you (they may even have it in their database anyways). You can drive with the bulb missing (Well, maybe not legally? But it would take a really terrible cop to give you a ticket on the way to the parts store with a bulb in hand!)

[chocolatekay]

Thank you for your speedy response!

I am hoping it is just a matter of replacing the bulbs! Good tip to take the bulb to a store and have it matched rather than trying to hunt around for a possible replacement online!

The bulb for the license plate is easy to locate, the rear fog light however, I have no clue and the manual is not helpful. I would be grateful if you could provide details on how to locate the rear fog lamp bulb.

Thanking you!

Kay :)

[shepd]

I wish I could help you, but Yarii in North America don't feature rear fog lamps. :( I would very much hedge a bet that it will be in one (or both) tail lights. Someone here must have removed/replaced the housing or light bulbs for the brake. However, I'm guessing you have a liftback. American Yarises ("Echo") of that age are almost all sedans.

The newer generation have you pull a small panel off behind the light. But I have no idea for yours, sorry.

[chocolatekay]

Not to worry, thanks for your help anyway. Hopefully someone else on here will respond.

Kay :)

[yarisugi]

Posting a photo of the rear of your Yaris may also help.
Normally, the rear fog is located inside of your tail lamp. It may be on the opposite side of your reverse lamp.

[CTScott]

^Exactly - You can access the bulb from the small pop off panel directly inside from the tail light. The bulb is a 382 (P21W)

[chocolatekay]

Thank you all for your replies.

It turns out there is an issue with the wiring for the rear fog lamp, the bulbs and fuses have been checked and changed.

I have I booked in at my local garage to further investigate, but am worried that I will have a huge repair bill awaiting me!

My car has a towbar installed - could this be part of the problem as ive seen a few posts mention towbars and wiring.....

Feeling a bit desperate now. Was hoping it would be a straight forward bulbnor fuse change. :(

Regards,

Kay

[CTScott]

Thank you all for your replies.

It turns out there is an issue with the wiring for the rear fog lamp, the bulbs and fuses have been checked and changed.

I have I booked in at my local garage to further investigate, but am worried that I will have a huge repair bill awaiting me!

My car has a towbar installed - could this be part of the problem as ive seen a few posts mention towbars and wiring.....

Feeling a bit desperate now. Was hoping it would be a straight forward bulbnor fuse change. :(

Regards,

Kay

It may be as simple as the RRFOG fuse being bad (in the under dash fuse panel) or the REAR FOG RELAY being bad (at the top of the under dash fuse panel).