Electrical Problem In Yaris 2008 Sedan

[VVIP]

I have an Automatic 1.3L 2008 Yaris Sedan. Some time back the power steering started to fail at times and the Electric Power Steering Column was replaced in July 2014(18 months ago).

About a month ago this problem came up again but this time all the other electronic components like the Radio, Air conditioning were failing and the engine suddenly stops and nothing works for about 5 minutes (can't start the car). this only happens occasionally. I checked the Battery terminals and it had Acid (white Stuff) on it. Went to the Battery shop and they replaced the Battery (under warranty) saying that one cell is leaking Acid to another and changed the battery terminal because the old one was corroded. However, the problem still remains.

Did a scan and the image has the results. The Fault codes were deleted but the problem still remains. Does anybody have any clue as to what the problem could be?

[MikeSh]

Sounds like an intermittent loss of power. As there seems to be corrosion around have you checked the Battery earth (negative) connections are all good and solid? (Should be heavy connections to the chassis and engine.)

[VVIP]

Put the car to a workshop and got the ground connections and positive connection to the fuse box checked using a volt meter while running the engine and everything seemed to be fine. There was no corrosion as well. Any other suggestions?

[MikeSh]

Possibly a faulty ignition switch? (If the contacts are worn or loose you might occasionally lose power to the ignition and/or aux circuits.)

You need to be a bit more specific about the symptoms:

Some time back the power steering started to fail at times ... About a month ago this problem came up again but this time all the other electronic components like the Radio, Air conditioning were failing and the engine suddenly stops and nothing works for about 5 minutes (can't start the car).

Do they all fail at the same time?

Does a single one fail, then work, then another fails?

When the engine stops are the dash warning lights on?

Do you wiggle the switch on and off during the 5 minutes or just leave it for a while and it then starts first try?

[VVIP]

12 hours ago, MikeSh said:

Possibly a faulty ignition switch? (If the contacts are worn or loose you might occasionally lose power to the ignition and/or aux circuits.)

You need to be a bit more specific about the symptoms:

Some time back the power steering started to fail at times ... About a month ago this problem came up again but this time all the other electronic components like the Radio, Air conditioning were failing and the engine suddenly stops and nothing works for about 5 minutes (can't start the car).

Do they all fail at the same time?

Does a single one fail, then work, then another fails?

When the engine stops are the dash warning lights on?

Do you wiggle the switch on and off during the 5 minutes or just leave it for a while and it then starts first try?

Yes all the systems fail at the same time (radio shuts off and AC fan speed gets slow) and the engine starts to miss and sometimes the engine stalls. If the engine does not stall everything goes back to normal after about 30 seconds and if it stalls everything is back to normal after starting the engine again.  The Power steering light on the instrument cluster came on for about 2 seconds when it happened once. Up to now none of the other warning lights have come on when it happens.

Of late it doesn't take 5 minutes to start the engine again it just starts up again immediately.

[MikeSh]

Certainly sounds like an intermittent power fault because when the engine dies you should get at least the oil and charge warning lights come on. But of course these things are a devil to track down because they aren't reproducible at will.

I'd suggest listing all the things that die or don't come on when this happens, then get a wiring diagram and trace them back to a common point. The problem should then be either at that point or somewhere upstream, but after wherever something that doesn't fail is fed. Bear in mind that the ignition switch could be a common point for both the aux and ignition circuits as it controls both.

[VVIP]

Thanks for the input MikeSh. Next time this happens I see if the headlights and interior lights works without a problem

[VVIP]

Ok it happened again tonight. The headlights, Radio, Cabin light & AC were all on when it happened. But I noticed it happening only when the power steering got hard and all other electronics got weak (Dome light, headlight and instrument cluster light became dim) AC fan became weak and the engine started to shiver. Before I noticed the symptoms my brother who was standing in front of the car noticed that the headlights was a bit dim. Then I shut off the AC and Radio and I Revved the engine while turning the steering wheel to see if the problem goes away and I noticed that at High RPM (around 4000 RPM) the power steering got loose (started to work) and the power steering light (P/S) came on for a few seconds. Then I turned off the engine and immediately tried to start it and it didn't (nothing happened even though the instrument cluster check lights were on) Then I put the key back to ACC and immediately cranked it and it started without a fuss.

I don't think it is a problem with the ignition switch since the headlights and Dome lights got affected as well. Could it be a faulty Alternator?

[MikeSh]

Clearly the voltage all over is getting very low. As the Battery is new we can probably eliminate that, so the volts are presumably being dragged down by a connected item. Yes, it may be the alternator.

It could also be something else that is putting a massive drain on the system, though I'd have expected most of those would blow a fuse.

In the UK getting an alternator reconditioned or swapped for a recon unit is relatively easy and not horrendously expensive, but you appear to be non-UK so you'll have to make local enquiries.