Possible ECU problem

[conchy_joe]

Good afternoon everyone,

I have a 2010 Yaris TR VVT-1-S-A. About three weeks ago I began to experience starting problems, after pressing the brake pedal and turning the key nothing happened. At first it seemed that if kept the brake pedal depressed and put the car in drive and then in neutral it would start.

However, just over a week ago it decided that it didn't want to start anymore. I had the car recovered to Halfords that evening. They kept the car for just over a day during which time they tried to find the fault, they even brought in someone with a diagnostic machine, he could not figure out what the problem was, he said it seemed that power was going into the ECU but not coming out. All the other electrics were working but not the ignition.

On Friday I had the car taken to Steven Eagell Toyota in Solihull, tomorrow they will do their own diagnostic test and let me know the result.

Has anyone experienced this problem, do you think that I'm looking at a new ECU.

[wildtapholer]

I'm guessing you have an auto gearbox as why would you press the brake to start, it helps everyone if they know what car you have, all we know the year 2010, we're not all psychic on here.

[conchy_joe]

It's a semi- auto gearbox with flappy paddles.

It's been regularly serviced since new and has never failed an MOT, the only work I have had done is new plugs last year, also I had the gearbox oil changed by Toyota Stourbridge, also last year.

[flash22]

2010 yaris auto will be the dreaded MMT, i would suspect the brake light switch, make sure your brake lights are working

i wouldn't let a chain or main stealer touch it

Ecu's rarely fail

[conchy_joe]

To be honest I didn't check the break lights, all the other electrics are ok, lights, indicators etc. Would a fault in the brake lights cause non-start issue ?.

[flash22]

Yes, it will cause a no crank

[conchy_joe]

Since the problem started there have been several cases of the brake pedal being solid when attempting start-up.

[conchy_joe]

Three weeks ago a woman in a two litre Audi SUV hit me when I was stationary at a roundabout. Amazingly there was no apparent damage to either car, but I needed a new muffler box and my license plate light had been pushed in. Could this be the reason for my problem.

[flash22]

If you pump the brakes, the pedal will go hard, if it goes rock hard like hitting a wall with little pedal travel that may be an issue, Any loss of brake fluid ?

[flash22]

3 minutes ago, conchy_joe said:

Three weeks ago a woman in a two litre Audi SUV hit me when I was stationary at a roundabout. Amazingly there was no apparent damage to either car, but I needed a new muffler box and my license plate light had been pushed in. Could this be the reason for my problem.

Did you have your foot on the brakes at the time ?

[conchy_joe]

Yeah, I was stationary at a really fast roundabout, being semi-auto I have to have my foot on the brake to stop " creep".

[flash22]

If the pedal was over extended pressure when you braced yourself you may have pop the shaft out of the master, done something to the master, servo or mangled the brake switch

 

[conchy_joe]

Bob, I didn't brace myself  it came out of the blue, as soon I felt the impact I switched off straight away and got out expecting to see carnage, there was absolutely nothing. The front of her Audi was more or less flat, as is the back of my Yaris, so it was like two hands clapping.

After we had exchanged details I drove about another twenty miles and the car drove as normal.

[conchy_joe]

What is strange is that Five days later I was in Kwik Fit, when I went to switch on and leave, it wouldn't start, I tried a few times and so did the mechanic but with no luck.

They said I could leave it overnight and we pushed it to a parking spot, just before I left I tried it one more time and it started. I drove home and a bit later went to start it and that was when it decided it had had enough.

[conchy_joe]

One more post before I sign off for the night.

I'll phone Toyota first thing tomorrow and let them know about the shunt I had, maybe it will give them an idea what to look for.

In any event I'll let you know the outcome of what happens. Maybe my experience will help another owner in the future.

Thanks for your help.

[TonyHSD]

After the accident did you talk to your insurance and request an assessment of the damage and eventually a repair? After even the slightest of impact between two vehicles always should seek evaluation of the damage because sometimes could be someone really important and expensive broken which may not be seen easily from outside. This is how many people have their AC lose gas and non functioning, after a very light hit in the front , that’s all it needs. 

[conchy_joe]

As there was no visible damage she agreed that should something need to be repaired she would settle privately or through her insurance. When I found out that my muffler needed to be replaced and also some trim under the trunk I phoned her and she put the money into my bank. The non start problem had begun a week or so before the accident.

[conchy_joe]

I phoned Toyota today, they said that the diagnostics ( probably Techstream ) had not found anything. He said that the engine doesn't know what gear it's in. I think flash22 may be on the right path with the brakes issue.

[Derek.w]

9 minutes ago, conchy_joe said:

I phoned Toyota today, they said that the diagnostics ( probably Techstream ) had not found anything. He said that the engine doesn't know what gear it's in. I think flash22 may be on the right path with the brakes issue.

The clue it shoud know if its in nutral/park, or drive.

[flash22]

11 hours ago, Derek.w said:

The clue it shoud know if its in nutral/park, or drive.

With MMT it can get complicated really quick as it's mainly electronic with ecu controlled actuators, the computer says no codes, op has a brake issue after a minor incident, the MMT uses a 4 pin brake switch also has no start (no crank ?) you can't start the car without the brake pedal being pressed

best bet is to have a look at the brake light switch on top of the brake pedal bracket, they can fail in many ways, if you have a new switch you can test it without fitting it, just plug it in hold the plunger down and see if it starts

A no cost way is to link 2 pins

84340-69075

A Toyota one is around £50, a cheap one is under a £10, i would pay a bit extra and get a half decent aftermarket item

eg.

https://www.ebay.co.uk/itm/334793179475

 

[conchy_joe]

Thanks Derek.w

                             Thankfully they've discovered the fault.......they found a wire that should have carried 1 ohm but was dead, they sent off for a Neutral Switch and problem solved.

Many thanks to  you all for your help.