Charging stopped due to system malfunction

[alflash]

The first video here shows this
Post in thread 'Charging stopped due to system malfunction' https://www.myrav4ev.com/threads/charging-stopped-due-to-system-malfunction.2692/post-32013

1. Both videos in https://www.myrav4ev.com/threads/charging-stopped-due-to-system-malfunction.2692/page-6#post-32013 show that the cabin heater is not on, although it has control pulses with an amplitude of 13.5 V and a frequency of 40 Hz.

2. In the message https://www.myrav4ev.com/threads/charging-stopped-due-to-system-malfunction.2692/page-7#post-32100 you wrote "I repeated the test with 40 Hz and heater got warm!".

3. Based on this updated information, I conclude that the cabin heater can work properly if the control signal has the correct frequency and amplitude.

4. In this photo from your video https://alflash.com.ua/2019/to_rav4ev/contr_bad.jpg you can see only the "remnants" or "embryos" of the control signal.

5. In order to finally remove suspicions from the cabin heater, this check (without connection to the heater, but with a resistance that simulates the load*) control signal RMI of (from) the Power Management Control ECU, that was recommended https://www.myrav4ev.com/threads/charging-stopped-due-to-system-malfunction.2692/page-8#post-32128
In other words, this test will confirm or refute the version about the malfunction of the Power Management Control ECU, which controls the cabin heater.
*Attachment.

 

[Rakesh Suresh]

p.s. If you have five minutes to spare, please check the fault codes in HVAC system (w/o scan tool) with the pump connector removed and the cabin heating turned on.

I don't see any error codes from the A/C test.

 

[alflash]

I don't see any error codes from the A/C test.

Thanks for checking.
Conclusion. If the HVAC pump is faulty, unfortunately, neither the system nor the driver will know about it...

 

[asavage]

Conclusion. If the HVAC pump is faulty, unfortunately, neither the system nor the driver will know about it...

How odd, as the pump's tachometer line is connected to the Power Management Control ECU. I wonder what they use if for.

 

[alflash]

How odd, as the pump's tachometer line is connected to the Power Management Control ECU. I wonder what they use if for...

Your question is correct.

Correction.
In the list of HVAC system codes there is one pump fault code.
For DTC B14C7 (memorized) Detection condition is "When the heater water pump is operating, the actual speed information (TWPSPD) from the power management control ECU indicates a value of 0 for 10 seconds".

But unfortunately, this code has no analogue among flash codes.

 

[alflash]

Howodd, as the pump's tachometer line is connected to the Power Management Control ECU. I wonder what they use if for....

View attachment 1065

If I'm not mistaken, this connector circled (in orange) is the D15 cabin heater control connector, which is also damaged...

 

[asavage]

That's a picture from bdunst, and he had repaired enough damage to get his heater working again.

Yes, that's D15. I believe he has an aftermarket JdeMO setup, which moves the harnesses around a little.

 

[Rakesh Suresh]

Use an oscilloscope to check the RMI signal (of D15) without connecting it to the heater, but with a 10kOhm fixed resistor connected between its pin (#3) and the PWR pin (#2). Compare the signal with and without this resistor and maybe that (step 1) will be enough.

Rmi voltage is 2.5v, but no heater control pwm visible.

In order to test without the resistor, I need to connect d15 back to the heater, correct?. I have only seen the trace of control signal when I connect d15 to the heater.

 

[asavage]

Is this a 10k resistor?

 

[Rakesh Suresh]

Is this a 10k resistor?

View attachment 1074

Oh right, forgot to mention that. I double checked. It is 9.91Kohm

 

[asavage]

I'm having a hard time making those five color bands add up to anything like 10k. Did you measure it out of circuit?

 

[alflash]

I'm having a hard time making those five color bands add up to anything like 10k. Did you measure it out of circuit?

Fot example, use https://digitalbunker.dev/how-to-read-resistor-band-colors-app/
1.Brown-> 1
2.Black -> 0
3.Black -> 0
4.Red -> 2 (multipliet 10²)
R = 100 × 10² = 10,000 Ohm.
5 Brown +/-1% (tolerance)

...
Rmi voltage is 2.5v, but no heater control pwm visible.

In order to test without the resistor, I need to connect d15 back to the heater, correct?. I have only seen the trace of control signal when I connect d15 to the heater.

Please,
1. Make sure that there are such (small) pulses on the RMI contact in the D15 connector
https://alflash.com.ua/2019/to_rav4ev/contr_bad.jpg
2. If they are there, then check the voltage on this contact with an oscilloscope when connecting the "load" resistance (without connecting the wired part of the D15 to the heater).
3. Show a photo of the oscilloscope screen of the result of such a measurement in this situation.

 

[Rakesh Suresh]

I'm having a hard time making those five color bands add up to anything like 10k. Did you measure it out of circuit?

Yes, I used a multimeter to test before the test.

 

[Rakesh Suresh]

Make sure that there are such (small) pulses on the RMI contact in the D15 connector
https://alflash.com.ua/2019/to_rav4ev/contr_bad.jpg

Please confirm if these are the steps.
1. Get control signal to show up on rmi by connecting d15 to heater.
2. Disconnect d15 and put in load resistor
3. Show photos of both.

 

[asavage]

Fot example, use https://digitalbunker.dev/how-to-read-resistor-band-colors-app/
1.Brown-> 1
2.Black -> 0
3.Black -> 0
4.Red -> 2 (multipliet 10²)

You see colors that are different than I see.

 

[alflash]

Please confirm if these are the steps.
1. Get control signal to show up on rmi by connecting d15 to heater.

Repeat the test shown in https://1drv.ms/v/s!AoMSicNQxi7y5lycb6nnksCMsNwx and then proceed to step 2.

2. Disconnect d15 and put in load resistor
3. Show photos of both.

 

[alflash]

You see colors that are different than I see.

What colors of stripes do You see?
I see that the tolerance band is probably brown (attach.3).

 

[Rakesh Suresh]

Repeat the test shown in https://1drv.ms/v/s!AoMSicNQxi7y5lycb6nnksCMsNwx and then proceed to step 2.

I tried everything I couid but I cant seem to get the control signal to appear again. I only see some high frequency signal. Oddly, this waveform is there on both RMI (Channel 1) and GND (Channel 2) wires (but not on PWR). I just realized that the difference from last time is that I have disconnected the pump connector. I can try again by connecting it.

(A bit off topic, but while I waited for 10 minutes with heat on trying out different settings, I got warm air in the cabin vents, presumably indicating that the PTC heater is likely working fine)

 

[Rakesh Suresh]

I just realized that the difference from last time is that I have disconnected the pump connector. I can try again by connecting it.

This was it. Control signal appears only when pump wire is connected.

Yay. I see the pwm now with the 10k resistor !!
D15 connected: weak control signal


With 10k resistor and d15 disconnected

 

[alflash]

Please make an oscillogram and show the result (photo) when connecting the D15 connector to the heater and when connecting this resistor* between +12V and the RMI signal.
I assume this will be the final test.
*In this way, you can compensate for a possible break in the conditional resistance Rload (attach.), which is probably located in the heater.