Mystery as to what’s wrong with my Yaris

[alexxjane]

Hi there, 

I’m experiencing a problem with my semi auto 2009 Yaris but my mechanics don’t seem to know what the issue is. Had the alternator replaced in October as well as the Battery on Monday just been. Then yesterday as I was driving back home waiting at the traffic lights the car lost power- the engine, oil and Battery light all came on. The RAC guys managed to get it started again and ran all the diagnostic tests before telling me this was an air supply issue and the car has a rough idle. We drove the car to the mechanics and he spoke to the RAC guy who told him the issue.

Today the mechanic has phoned me and said he spent an hour doing the diagnostics and can’t work out what’s wrong with the car? I called Toyota themselves and they said it could be spark plugs?

I feel like I’m getting so many mixed messages and it’s left me feeling like my car is unsafe. I’ve only had it for 18 months and I’ve never had so many issues with a Yaris before 😞

[Starensis]

I’d get them to check main red power cables from/to Battery and alternator. Check they are all tight.

[Cyker]

Why are garages so bad at diagnostics these days! We need more people like DiagnoseDan!!

 

[YarisHybrid2016]

They're trained to replace parts; not think.

Do lights look dimmer than usual? Do they change brightness with RPM?

[alexxjane]

The lights are fine. I will get them to check on the red cables mentioned upthread too 

[flash22]

Contact the RAC and ask for the report or codes what is the mileage ? 1.33 I take it ? How much fuel is in the tank ?

[PCM]

I had a Battery replaced once.

Car when parked one time would not start - all dead.

Turned out a Battery connection was loose. A one minute fix.

[Knorton]

My son had problems with Corolla T sport a few years back. Battery dying. No alternator light up, changed Battery problem persisted, checked alternator & charging fine. Turned out the crimped terminal on the positive lead was not making proper/intermittant contact.removed old terminal/cut back cable (enough wriggle room to do this) crimped on new terminal. Problem sorted. 

[Devon Aygo]

What model & engine and with all the lights on what were the fault codes stored?

[alexxjane]

It’s got half a tank of fuel and the RAC were the ones who suggested it was the air supply but didn’t give me a code or anything. They even told the mechanic what the issue was when we drove it to the garage but the mechanic still can’t work it out which is really frustrating. Apparently they took it for a test drive and ‘nothings wrong’ but there clearly is as it wouldn’t break down for no reason lol 

[bathtub tom]

On 3/17/2023 at 3:00 PM, alexxjane said:

waiting at the traffic lights the car lost power- the engine, oil and battery light all came on. The RAC guys managed to get it started again and ran all the diagnostic tests before telling me this was an air supply issue and the car has a rough idle.

How long have you had the car? How many miles has it done? When was it last serviced? What, if any work was done on it before this event?

It seems to me the engine just cut out and the RAC diagnosed an inlet problem. I wonder if 'the mechanic' is just looking for fault codes, without doing a proper diagnosis. Who is this 'mechanic', not a tyre 'fit quick' type place is it?

[flash22]

Stupid question - do you have lots of other stuff on your car keys ?