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

 

[bdunst]

After tackling this heater project with lots of help a while back - it finally got cool enough I thought I would check my heat - and it was really lukewarm. So when I got home I opened the hood to find the rodents had decided to warm up with the cooler nights as well. I repaired 2 of these wires to the pump when I replaced the heater. Luckily NAPA had the connector in stock and I was able to pick it up this afternoon and splice and solder the wires. Heat is back functioning again.
Reminder to check for rodents as the weather cools and winter is on the way.

 

[asavage]

Peppermint oil, coyote urine . . . I've heard mixed results using either as a topical deterrent.

I recommend leaving the pretty plastic decorative non-functional cover off, the one that covers all of this up. Store its screws in the brackets they normally reside, and store the cover somewhere for when it's time for resale. I pull those off on all my cars.

I just found a rats nest under my friend's Sienna's engine cover last month, nestled in the injector wiring. Now he stores that cover in his garage

 

[alflash]

After tackling this heater project with lots of help a while back - it finally got cool enough I thought I would check my heat - and it was really lukewarm. So when I got home I opened the hood to find the rodents had decided to warm up with the cooler nights as well. I repaired 2 of these wires to the pump when I replaced the heater. Luckily NAPA had the connector in stock and I was able to pick it up this afternoon and splice and solder the wires. Heat is back functioning again.
Reminder to check for rodents as the weather cools and winter is on the way.

Thanks for info!

I wonder if the heating came on when the pump was not working and if there were any fault code(s) in the HVAC system?

 

[bdunst]

The pump was working - but seemed about 1/3 speed. so it was warming but very slowly as it pumped thru the heater.
1 wire was broken - 2 were just a few strands - but different than last time - the ground wire was intact. once cleared - pumping normally and getting hot fast. So I did not check for any codes since its all working.

 

[alflash]

The pump was working - but seemed about 1/3 speed. so it was warming but very slowly as it pumped thru the heater.
1 wire was broken - 2 were just a few strands - but different than last time - the ground wire was intact. once cleared - pumping normally and getting hot fast. So I did not check for any codes since its all working.

Thanks for the clarification.
As I can see in the photo, the rats gnawed through the white wire with a black longitudinal stripe (pin #1), through which the negative power supply (GND) was supplied. Without this, the pump could not work.
https://alflash.com.ua/2019/to_rav4ev/hvac_pump1.png

That is why the interior heating was carried out by a PTC Quick heater.

The HVAC system error codes are read without scan tools after several presses with two fingers on its control buttons https://www.myrav4ev.com/threads/charging-stopped-due-to-system-malfunction.2692/page-4#post-31958

 

[asavage]

I'm going to put a couple of things here, so I can find them later, in a logical place.









The next image is apparently too large (wide) a PNG for the forum to generate a thumbnail, so you have to click on it. It's the wiring for the underhood parts of the Cabin Heater (no user controls wiring). Toyota put the coolant pump wiring on a completely different diagram than the heater control wiring, and I pulled them out and put them on one page.

View attachment Cabin_Heater_Only_01b.jpg