Toyota Aqua 2016 Problems & Solutions

Hi All,

I have a Toyota Aqua, S Style Black, Model 2016, Import 2018 & Registered 2019. I will be using this thread to post my questions and look for solutions.

1. I got this car at about 75,000kms. Now it is at 150,000kms. I am currently using Toyota Petron Plus 10W30 but planning to switch to 5w30. Would it be a wise thing to do at this stage?
   
   
2. What is the transmission oil change interval for this car? I've been reading here and there that it does not require replacement? I am having a hard time accepting that.
   
   
3. I hear a rattle from underneath the car at low revs, probably from the EGR unit as I remember i got the car lifted and tapped on the rectangular unit and it rattled from inside. No check lights, no change in exhaust sound, no drop in mileage etc. What should be done here?

 

Appreciate your response. About the last point. Yes you are correct I meant to say the exhaust heat recovery system. The shields are all tight and the rattle comes from inside the rectangular equipment. If i punch it when the car is lifted, i hear metal rattling from the inside. Is that item repairable or should i look for a replacement?

 

My car's doors do not lock/unlock automatically based on certain criteria defined in the user manual of Prius C. It also shows no customisation option in Techstream. Is it safe to assume that JDM variants (Aqua) are devoid of this capability?

 

Hi Guys, i am back with another problem in my Toyota Aqua.

While driving today, my car started showing ABS/VSC lights and the brake lost all assist power and it became very hard to brake.

I connected it to Techstream and it shows C1A50 (Brake System Malfunction) and C1391 (Abnormal Leak in Accumulator). I cleared the codes and drove the car and everything appeared to be back to normal. However, the accumulator pump now seems to run for 3-4 seconds after every 15 seconds or so.

Need guidance on what went wrong and what would be the required corrective action? Does this car (2016 Aqua/Prius C) have separate units for brake accumulator and pump or is it a single unit?

 

Thanks for responding.

I hope you can help me understand the issue. My understanding is that the main issue is the abnormal leak in the Accumulator (Part 1) and due to that abnormal leak, another Part 2 (pump?) now has to work more frequently and for longer intervals which will ultimately result in its premature failure.

What's the exact name for Part 2?

These JDM cars are imported in my country without any official service/parts available and the routine practice amongst Prius users here has been of replacing both parts sourced from junkyard.

What if I don't prolong the issue and only replace the Accumulator (Part 1)? Isn't the second part (pump?) still functional and should revert to its original functioning if the abnormal leak is handled?

 

Thanks. That's helpful. Since the code says "Abnormal Leak in Accumulator", i am assuming the culprit is the Accumulator. I was thinking to get only the accumulator replaced first and see if it solves the problem.

 

So i am back with a new situation and a few questions.

1. Frequent non-EV running
After observing for about two weeks, i have noticed that the car's engine runs more frequently than it used to do until last year same days (it's the start of winters here). Even with the car in Park, HV battery fully charged (8 bars), warmed up coolant and no ac/heater, the car either does not switch to EV mode or if it started off in EV mode it will just switch on the engine and idle for as long as it's powered on. The HV bars keep moving between 6 and 8.

In such condition, Techstream tells me that Engine Idling has been requested under Hybrid Control and under Engine Control it shows me that the engine is operating Independently. The HV block voltages are within 0.5 Volts of each other. Changes are also uniform on stress.

The car does behave well after being parked overnight but only for a couple of short trips and then we have engine running almost all the time for the remaining, specially longer trips of the day.


2. Engine Shudder/Missing
The engine has a noticable missing / shudder when in low RPMs / speeds upto 30/40 km/h / when HV battery is down to 2 bars. Except for these conditions, the engine and throttle response is stable. If I engage cruise control at speeds between 50 and 55 km/h, i can feel and see the RPMs(techstream + bars in the eco meter)moving between 900 and 1200 in a pulse-like fashion on a straight and flat road. This does not happen at speeds above 55/60 km/h.


There are no codes. The car is about 194k KMs driven and maintenance has NOT been neglected. Would appreciate if i could be pointed in the correct direction to resolve these issues.

 

thanks. any feedback on the second point?

 

there's no rattle. Its vibration/shudder and there is a loss of power when it's happening. And the RPM fluctuates when the car is cruising at around 50/55 km/h even on a flat road.