Yaris hybrid 66 plate head light fault

[Djdellboyl]

Hi my wife s Yaris hybrid 66 plate. Headlight’s come on  on ther own when car has been locked for hours. 

[flash22]

Has it had a new 12v Battery yet if not it needs replacing - it's an AGM type made by Yuasa, Toyota  Main stealer (Parts Dept) do them for around £120 (ask for a discount) others have them for around £130-150+

 

Yuasa S34B20R - Toyota. 28800-YZZPC

 

[Djdellboyl]

Hi my wife has a Yaris hybrid 2016 the headlights come on one there own and refuse to turn off, any ideas please. Thanks 

[flash22]

The lights just randomly turn on ? That is usually a sign of a weak or dying Battery

[FROSTYBALLS]

Topics merged.

[Djdellboyl]

On 4/25/2022 at 5:25 PM, flash22 said:

Has it had a new 12v battery yet if not it needs replacing - it's an AGM type made by Yuasa, Toyota  Main stealer (Parts Dept) do them for around £120 (ask for a discount) others have them for around £130-150+

 

Yuasa S34B20R - Toyota. 28800-YZZPC

 

Hi thanks but it went into Inchcape Toyota at Sandhurst £104 for diag thay stated water ingress in fuse box New fuse box & part wireing loom £3000.00, I’ve just had a auto Electical guy check it out ( not a sign of parst or present water ingress or corrosion) I’ve been a mechanic all my life, now at 73 I’m retired but kno little of auto electrical  been advised it may be a body control module fault ?

[flash22]

Change the Battery, low voltage makes modules go crazy, I have come across this type of issue a few times - a dealer will charge the Battery then test but not under load, and it will show as good, these are an AGM type Battery (deep cycle) they take a low current <4 amp and slow charge when these start to fail they drop their current carrying capability as the current rises the voltage drops, lockdown killed off a lot of batteries

tbh most dealers are just parts fitter these days and do what the computer tells them to do

there's at least 2 threads on here with the same issue

[Djdellboyl]

On 5/4/2022 at 9:54 AM, flash22 said:

Change the battery, low voltage makes modules go crazy, I have come across this type of issue a few times - a dealer will charge the battery then test but not under load, and it will show as good, these are an AGM type battery (deep cycle) they take a low current <4 amp and slow charge when these start to fail they drop their current carrying capability as the current rises the voltage drops, lockdown killed off a lot of batteries

tbh most dealers are just parts fitter these days and do what the computer tells them to do

there's at least 2 threads on here with the same issue

Hi thanks for your reply, just received more information about the faults on the Yaris, part of the wireing loom up under the dash has burned out no signs of water ingress I’m wondering is any of you guys have herd of this on other Yaris owned by members. Thanks. Derek. 

[FROSTYBALLS]

What wattage headlight bulbs are fitted?

[flash22]

That doesn't sound right as the controls inside the car are all low current, control side

do you have any pic's

[Djdellboyl]

2 hours ago, flash22 said:

That doesn't sound right as the controls inside the car are all low current, control side

do you have any pic's

Hi the Toyota dealer has some the tec took when it went for diag. I’ve asked 3 times for them not got as of yet. 

[Djdellboyl]

1 minute ago, Djdellboyl said:

Hi the Toyota dealer has some the tec took when it went for diag. I’ve asked 3 times for them not got as of yet. 

After thay quoted £3000 plus we brought the car back home to think about it first. 

[flash22]

Did you change the Battery ?? The car is fine apart from the lighting issue ??

[Djdellboyl]

4 hours ago, Djdellboyl said:

After thay quoted £3000 plus we brought the car back home to think about it first. 

Hi I now have the pics 

[Djdellboyl]

4 hours ago, flash22 said:

Did you change the battery ?? The car is fine apart from the lighting issue ??

The car is fine just no dip or main beam

[flash22]

Do you get any sidelight or main beam light on the dash at all ?

Verify the bulbs are working

there are around 8 fuses and multiple relays in the system

[Djdellboyl]

Hi I have the green dash side light indicator light plus if I switch to main beam the blue dash indicator lamp comes on with the clunk noise ( poss a relay opens ) day driving lights ok front and rear side lights ok. Just no dip or main beam , I’ve attached 6 pics from the tec at the dealership. Just wondering if anyone else has had this burn out faults. Can’t see any water damage. 

[flash22]

That is very odd it shows signs of corrosion may not of been moisture but the plastic degrading from heat or even a bug/spider

disconnect the Battery and remove the plug give it a scrub with a stiff tooth brush and some IPA (isopropyl alcohol)

there are a few options, i will have to sit down and work-out the pins and what they are related too

[flash22]

That is connector 3C (B) the male socket should clean up no issue, a stiff brush and may be a pick

please, can you check the 15a washer fuse (windscreen washer pump)

[Devon Aygo]

46 minutes ago, flash22 said:

That is connector 3C (B) the male socket should clean up no issue, a stiff brush and may be a pick

please, can you check the 15a washer fuse (windscreen washer pump)

You are way better than I at interpreting EWD would the damaged terminals be related to washer pumps? As it has been noted before on Gen 3 Yaris where an internal failure of the washer pump allows screen wash into the pump connector, capillary action then lifts the water up into the body computer and then ensues weird electrical faults:

• Washers not functioning/running until pump fails
• Lights coming on/off at random
• Door locks not functioning/opening/closing at random of constantly cycling
• Parasitic drains damaging 12v Battery

[flash22]

I know nothing, will water track that far, makes sense as it's pin pointed in one spot

Highlighted in green are the affected pins

5. Washer 15a - light blue - wired directly from the washer pump to connector 3C

6. Washer 15a (rear) - Yellow - wired directly from the washer pump to connector 3C

 

17. Reverse switch - Gauge 10a - Red

18. H-LP Relay - Violet - control side (bingo - headlight main relay)

 

32.ECU-IG No. 2 - Light blue - ABS and Traction control

33. Reverse switch - Gauge 10a - Red

 

as i said, there are a few options you could take, it looks like the culprit is the washer pump (on PIN 5)

[Djdellboyl]

Thank you so much you are the absolute dogs b—-   You must know your way round Toyota wireing systems A1. After I’ve fired I few into my inchcape dealer for leading me astray first off with what thay told my misis when she collected it after diagnosis , as I stated before been a mechanic 49 years ( started serving my apprentice in 1966 ) now retired but my auto elec is very limited ( can bus what the F —- s that ) lol, once again thank you so mutch. Is there any thing I should subscribe to ?  King regards Derek. 

[Cyker]

This is like watching an episode of CSI or something!  

Nice detective work you lot  

 

[Djdellboyl]

1 minute ago, Cyker said:

This is like watching an episode of CSI or something!  

Nice detective work you lot  

 

Yes those 2 are the business, theas days not to meny go out of there way to help. My thanks to both of them 👍

[flash22]

Replace the washer pump, a used engine bay harness is £150-220 or you could just overlay the wiring and fuse the washer pump(s) in the engine bay (remove the offending wires from that connector inside the car), The headlight control wire can be rerouted to connector 3A, alternatively you could re-pin the 3C connector into a new housing and overlay the washer pump wiring

Devon works for a dealer, so has access to systems i don't or would have to pay for

i like the forums as i can bounce ideas around, it gives another perspective on it

 

@Djdellboyl i may be able to source some used replacement connectors/housings