LIMP MODE PROBLEM SOLVED - I THINK

[Martin Bruce]

I bought a 2006 1.3 VVTi earlier this year and it sometimes had jerky throttle response and went into limp mode at lower speeds around town. It restarted normally after pulling over so I was not without hope.
I had the fault codes checked at a local garage and later by my own OBD Meter I bought.
Fault codes: P2103 - Powertrain Throttle Actuator Control Motor Circuit High
P2111 - Powertrain Throttle Actuator Control System Stuck open.



I had already changed the PCV Valve to a new one and this seemed to help, but not solve the problem.
I narrowed the problem down to the Throttle Body needing replacing (had tried cleaning the throttle flap/throat to no avail).
The recommended OEM Throttle bodies were either 'out of stock' or hugely expensive e.g Hitachi - £840.
I got one off AliExpress for £54 plus £14 shipping - it took a few weeks to get here.

I just fitted it myself - a bit scary, but only took a couple of slow hours.

I started it up, idle was a bit high but settled down as per ECM control should do.

Anyway this seemed to have solved the problem - it runs a lot smoother now.

Most of the electrics on the Throttle body are made in China anyway, it's not a carburettor.

[Martin Bruce]

This was the original and new Throttle Body - you have to be precise on ordering the right one - know your engine spec!

[Martin Bruce]

Can you imagine what the Toyota dealer price would be to fix this, assuming they knew how to fix it? Or even your local, family-run 'friendly' garage?

Now running smoothly:

[Martin Bruce]

Original recurring Fault codes:

[Martin Bruce]

Delivered during lockdowns / pandemic, I can tell you it's a relief to be free of that annoying limp mode threat hanging over my head. Hopefully the fuel efficiency should improve too!

[bronsin]

Outstanding! I hope this helps others with similar problems

[sh0rtlife]

sadly the areas that "need" cleaned are typicaly the parts the electronics controll, so one would need to remove them to clean the passages

[Martin Bruce]

This guy on Youtube claimed he fixed his Toyota Throttle Body by cleaning the gears etc., maybe worth a try if you're at a last resort (I may keep my old one and try and refurb it):
https://www.youtube.com/watch?v=UGIgk8p1qus

[Martin Bruce]

Originally Posted by bronsin

Outstanding! I hope this helps others with similar problems

Thanks

[Martin Bruce]

Further to my earlier posts - I have LIMP MODE Problem again, same fault codes. It was improved but issue seems to be connected to low ambient temperature also., i.e car ran better in summer months, winter months gives more limp modes.

Battery is around 15 years old, I am now replacing that, now (maybe insufficient power to drive throttle motor? Heavy wiper / lights use?
ECM?
I suspect it may be coolant thermostat not fully opening / closing - will look into this.
WTF!

[bronsin]

15 year old battery? Hard to believe but time for a new one!

Do you know anyone with a similar car you could swap parts with? I fixed my sons 2000 Echo by treating the airflow sensor with my 2009 Yaris. When I did His code went away and mine through the same one he had. A rebuilt airflow sensor solve the problem.

[Martin Bruce]

Originally Posted by bronsin

15 year old battery? Hard to believe but time for a new one!

Do you know anyone with a similar car you could swap parts with? I fixed my sons 2000 Echo by treating the airflow sensor with my 2009 Yaris. When I did His code went away and mine through the same one he had. A rebuilt airflow sensor solve the problem.

Bronsin, Do you mean the MAF (Mass Air Flow Sensor)? I did clean that a while back, didn't seem to do much. No, I don't know anyone with a similar vehicle. My battery was 5 years old, not 15, sorry, made mistake reading age there, just topping up a new replacement. I think old battery was ok actually but, have to eliminate all possible causes of problem.
Problem seems to be temp related, like turning on the interior heater, but that wouldn't explain the fault codes. Could be dodgy wiring to Throttle Manifold or ECM.
I took off and checked the Gas Pedal earlier this year - it was part of the Toyota recall and has been shimmed with a green tick sticker so should be ok.
This model has a rep for bad idle / rough running/ limp mode problems I found out anyway. Toyota at fault here.
I did notice the black plastic filter housing that contains the MAF and fits onto the throttle body was cracked, but I put some Duct Tape to cover the crack, I should replace it really.

[bronsin]

Yes my problem was the MAF sensor. Do you get YouTube? There’s a mechanic named Scotty on YouTube who has all kinds of videos about car problems. You might search your area codes on YouTube for suggestions.

[Martin Bruce]

Originally Posted by bronsin

Yes my problem was the MAF sensor. Do you get YouTube? There’s a mechanic named Scotty on YouTube who has all kinds of videos about car problems. You might search your area codes on YouTube for suggestions.

Bronsin, I have just cleaned the MAF Sensor, and the PCV Valve, and now replaced the Battery. It seems to run a lot better now, been alright for a few days now, inlcuding a longer trip out of Town. After Battery disconnect, ECM has to relearn ideal settings.

Yes, I have seen some of Scotty's vids on YouTube - he is quiet useful.

[Martin Bruce]

Originally Posted by bronsin

Yes my problem was the MAF sensor. Do you get YouTube? There’s a mechanic named Scotty on YouTube who has all kinds of videos about car problems. You might search your area codes on YouTube for suggestions.

Bronsin, with the cold weather here now (-1C) my Yaris has been going into Limp Mode daily and driving me crazy - that is until I tried Scotty Kilmer's YouTube Toyota ECU Reset Fix. It may have finally cured the problem!

https://www.youtube.com/watch?v=F6pMlbNW7-E

Basically: (With Key Off)

1. Disconnect BOTH Battery cables , starting with Negative.

2. Short the + and (-) cables together using a wire and croc clips for a few minutes

3. Put the sidelight switch on to drain any remaining charge in the ECU

4. Turn lights off, reconnect Battery cables, starting with positive, and leave for a few minutes.

5. Start Engine and idle at 2,000 revs with things turned on as you would normally drive , i.e A/C or sidelights etc. for a few minutes (Scotty says 5 min, I did 3 min)

6. Allow idle to drop to normal, then idle again at 2,000 rpm again for a few minutes with no load on (from lights, A/C).

While the Battery was off, I also unplugged the sockets to the ECU (after a few minutes) and sprayed the plugs with WD40 , then reconnected them. (This was an awkward job in itself, but I won't go into details here). I thought I might have a bad connection or corrosion as the fault codes always said 'Powertrain...'

Anyway, Yaris is running good now and I have along trip ahead this Sun, thanks

Can't believe Car Makers allow their products to be this tempermental!

[Martin Bruce]

Further to the post directly above, Scotty Kilmer has changed his tek slightly and now advises the use of a 1 Ohm Resistor between the battery cables (while NOT connected to the battery) when doing a reset:

https://www.youtube.com/watch?v=1tiCXAr-Uho

I did not use a resistor, and my 2006 Mk2 Yaris was fine after the reset and is running well now.

[bronsin]

Let’s cross our fingers!

[bronsin]