It will be a long read but if u r having any such problem do read, it might save u lot of money
I purchased Toyota IQ last month .. overall car was in good condition but had a weak acceleration .. my first though was CAT (chocked ),so went to a shop and checked it was quite clogged so we cleaned CAT without acid treatment .. but not much improvement.
On motorway once speed touched 120kmph i got VSC off (blinking), Traction control on and engine check light .. resetting did not solve the problem .. it would turn on again after a while
Went to diagnostic setup and got a 3 page list of faults
studying on Net (not the diagnostic report but the combination of lights) pointed out that this is a oxygen related fault
Following actions taken in next few days
- Put genuine air filter (to rule out air choke)
- Cleaned throttle body and plugs, set plug gaps
- Cleared all error codes
I visited Summandar khan shop in pindi and he attached diagnostic unit and advised opening timing area since cam and crank timing errors were there .. demanded 2500/- for labor only and assessed that advance timing sprocket is faulty might have to be replaced
I visited Arshad In chah sultan (very famous shop) and he told me similar story with 8000/- labor charges only
I studied net and found that newer generation cars when turn on more than one light, then sometimes it is pointing to a specific area and may not be related to type of light .. so in my case one of the solutions i came across was to open fuel lid and put it back on .. I did it and the lights turned off .. it has been a week and no light .. no issues
Now i was left with a poor acceleration and slightly rough idle .. here is what all i did to smooth-line both issues
- used liquid moli injector cleaner
- filled tank with hi-octane twice
- got a thorough service from underneath
- What actually was the fault was a loose battery wire ... not from the terminal but from the wire end .. somehow it was hidden in cover and it has a nut bolt to keep it in place but there was no bolt there .. it was totally loose .. causing all those idle issues and less power initially ..
- lastly i did a hard reset by keeping terminal off for about 15 mins .. shorting them before putting back and then 15 min of idle without turning on any electronics on car
All is perfect now from acceleration to idle and no fault indications
Summary
CAT was chocked
Air filter was local and chocked the system
Throttle body was dirty
Plug gap was incorrect
Fuel lid was open (main Fault) would give less pressure to fuel ... correction made
Battery positive was loose (main fault)
ECU needed a code erase and reset
Injector cleaner and hi-octane helped
Hope it helps someone .. i was thinking what fault would have been diagnosed by those big name workshops and what parts would i have prchased for no reason .. my advise find solutions on net before believing any mechanic or expert ..
update (15-7-18)
the tuning processes above did increase the performance of car but actual culprit was not any of above
the fault was removed in a triple process .. i am busy these days but will soon write down detail how the core issue was resolved .. do note not one workshop or expert was able to asses fault .. from toyota motrs to honda motors .. yet two people on pw did guide me on the write path which will put in my details later
