ALL POSTS - Heater Failed - Service Bulletin TSB 0111-14

[bdunst]

I put it all back together and I can't get it to go into ready mode - It also wont charge.

So I checked my 12 volt battery - which is 3-4 months old (but the car has been sitting a month or so with no charging or driving)
The 12 volt battery measured 11.32 volts - which double surprised me - so I have it on a charger - I will disconnect it and reconnect it once fully charged. Hopefully that will solve the problems.
My last 12 volt check was to see what the voltage was when the car was on - it was 14.something - so i assumed dc-dc was working.,
The only things I disconnected were - 12 volt battery - high voltage plug - Jdemo plugs 1 & 3 and the plug the heater pump that had broken wires.
I never disconnected the HV Plug before but it seemed to reseat ok.

 

[miimura]

Be sure that you re-installed the service plug under the front passenger seat correctly. If it's not, the car won't go READY and won't charge.

 

[alflash]

Notes
1. HEATING / AIR CONDITIONING SYSTEM of RAV4EV has the following fault codes:

• B14C4 Electric Water Heater Circuit,
• B14C7 Electric Water Pump Circuit.

And have active tests "Water Pump (On/Off)" and "Electric Water Heater (On/Off)".

2. Some trouble codes on this system can be read without using a diagnostic scan tool



3.
An example of an incorrect installation of Service Plug Grip

 

[bdunst]

Thanks guys - I charged the 12 volt battery up - reconnected 12 volt - same as yesterday - car powers up - everything looks good like a normal 12 volt reset - no check EV or other error - a handful of trouble lights lit - seems normal - but second press of on button does not go to ready.
I turned the heater on - i think i felt flow on the heater hose out of the pump - did not leave on long enough to get hot - if it would get hot if not in ready mode.
i tested the 12 volt battery voltage after all these attempts - still at 12.67
I disconnected 12 volt again -waited 10 minutes - disconnected HV plug again.
Car went to READY

Tried heater - definitely a flow that wasn't there before. Seemed like a little warming - definitely not full heat.
also aux power only showed about 1K.

is 20,000 ohms on heater test mean good or bad?

 

[bdunst]

Notes
1. HEATING / AIR CONDITIONING SYSTEM of RAV4EV has the following fault codes:

• B14C4 Electric Water Heater Circuit,
• B14C7 Electric Water Pump Circuit.

And have active tests "Water Pump (On/Off)" and "Electric Water Heater (On/Off)".

2. Some trouble codes on this system can be read without using a diagnostic scan tool



3.
An example of an incorrect installation of Service Plug Grip

Thanks Vlad, i will give that test a go next, i think your video on hv plug was exactly what i did, handle not fully up when reseating, with handle fully up, reseated and worked.

 

[alflash]

Thanks Vlad, i will give that test a go next, i think your video on hv plug was exactly what i did, handle not fully up when reseating, with handle fully up, reseated and worked.

Ok

1. Cabin Heater receives power from the HV battery when the contactors are closed.

2. If you have a current clamp, you can check the current of this heater as shown in this video ( time 00:26)


3. Тake a look results of cabin heater resistance check in https://www.myrav4ev.com/threads/al...e-bulletin-tsb-0111-14.823/page-14#post-30438

If it is not difficult, please show photo with the results of the measurements.

p.s. Please show how you made the connection of the three heater control wires. Does the "new" heater have the same connector as the "native" one and the same purpose of the contacts?

Note. Measuring the resistance between the heater's supply contacts is essentially measuring the sum of the resistances of the collector-emitter junctions (semiconductor barrier) of the four parallel IGBT transistors with heater elements and the input impedance of the insulated HV part of the heater's control board.

 

[bdunst]

The heater I am going to use to replace is a brand new Rav 4 EV PTC heater. Much like the tests is the thread referenced in item 3 - the resistance across the failed heater and the new heater are the same - given correct polarity on the plug.
The new heater has the dc-dc connector wire, the tab connection wire and the ground connection wires with a connector at the end of the ground wire that I have not yet traced. - I am considering just attaching the existing ground cable to the heater and removing the new one if it's hard to trace to the end. I have everything undone except for 1 heater hose - I am hoping to get that off - install the new heater and get it all back together this afternoon.
I have continuity in the dc-dc test - so I believe like PH2 - I have the heater problem without the DC-DC problem. I am guessing when the mice chewed thru the pump wires - it caused the downstream heater failure - may be due to no coolant circulating.
I will take a pic of the new heater and report back when this is complete.

 

[bdunst]

I HAVE HEAT!
other than a clamp coming off and leaking coolant everywhere, install was painless.
still have to button down jdemo but otherwise all good.

Thank you everyone for your help!

 

[asavage]

The heater I am going to use to replace is a brand new Rav 4 EV PTC heater.

A note: the water heater Cabin Heater with the circulation pump . . . AFAIK it's not PTC.

The RAV4 EV (and a lot of other Toyotas) do have a 12v 840W PTC heater, but it's an air heater, not a water heater, and it's in a very inaccessible location.

If you run a PTC (Positive Temperature Coefficient) heater without "cooling" it (moving heat away from it), its internal resistance rises to limit current flow and prevent self-destruct.

I have a feeling that the water heater under the hood may have some built-in limiting, maybe via temp sensor(s) and electronically limiting the current, but it's not PTC.

 

[alflash]

I HAVE HEAT!
other than a clamp coming off and leaking coolant everywhere, install was painless.
still have to button down jdemo but otherwise all good.

Thank you everyone for your help!

Congratulations, great result!

I'm guessing the source of confusion about how the cabin heater works is this service bulletin, which calls it PTC Cabin heater

https://alflash.com.ua/2019/to_rav4ev/cabin_heater.jpg
https://alflash.com.ua/2019/to_rav4ev/cabin_heater.jpg

An experimental test of the dependence of the resistance of one heating element on temperature showed that with an increase in its temperature from 20 to 100 degrees C, the resistance decreases by approximately 2.5 times.

The Cabin heater Controller uses bidirectional Hall Effect-Based Linear Current Sensor ACS758LCB-050B-PFF-T to check the total current from the HV battery.

Update. I hope to check soon whether there is a dependence of the conductivity of the heating element of the cabin heater on the magnitude of the applied voltage.
It is interesting to know the meaning of this parameter, known as Switch Temperature, Curie Temperature, Reference Temperature, Transition Temperature
The temperature at which the resistance value of the PTC thermistor increases to twice the zero-power resistance, also called PTC thermistor Curie temperature, or PTC thermistor Reference temperature, or PTC thermistor transition temperature.

 

[asavage]

Maybe it really IS a PTC heater, but I am suspecting not, as Toyota's documentation of the RAV4 EV has been of spotty quality.

 

[bdunst]

Al, When I was searching to buy the ford and nissan heaters, both rfer to this heater as a liquid PTC heater.
The Rav doc suggests that and if I recall the rav fuse doc calls them ptc heater fuses

 

[alflash]

Al, When I was searching to buy the ford and nissan heaters, both rfer to this heater as a liquid PTC heater.
The Rav doc suggests that and if I recall the rav fuse doc calls them ptc heater fuses

The fuses through which 12 volts are supplied to RAV4EV cabin heater (aka Heater No. 1 Bracket Sub-Assembly) are called A/C-IGCT (10A) and IGCT 3 (20A) in the manual.
The 3 Quick Heater Assembly modules are powered by three PTC HTR 1/2/3 (50A) fuses.

 

[alflash]

Announcement.
Checking the dependence of the resistance of the heating element of the cabin heater on voltage and temperature.

https://alflash.com.ua/2019/to_rav4ev/heater_check.jpg