Charging stopped due to system malfunction

[Rakesh Suresh]

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.

Before connecting d15


After connecting d15


Video showing this
View attachment 20241030_174313.mp4

 

[asavage]

It appears as if you plugged in D15 to the heater, but didn't disconnect the 10k load resistor when plugged in, which is what I would have like to see.

 

[Rakesh Suresh]

It appears as if you plugged in D15 to the heater, but didn't disconnect the 10k load resistor when plugged in

Correct, I did not disconnect the resistor when I connected d15

 

[alflash]

This is what we know now.
1. According to https://www.myrav4ev.com/threads/charging-stopped-due-to-system-malfunction.2692/page-7#post-32100 the heater can work using control from an external simulator (NE555).

2. Now we know that the control signal from the PMC ECU without connection to the heater, but with an external load resistance (10 kOhm) is quite adequate.

3. The control signal from the PMC ECU when connected to the heater looks only like a "trace" of the correct signal. https://www.pravda.com.ua/news/2024/10/31/7482262/ Perhaps this is somehow related to such an input circuit LIN Transceiver (attach.) of the RMI signal located on the heater board.

4. Oddity/misunderstanding/questions.
Why does the control signal from the simulator only slightly reduce the amplitude when connected to the heater. And the signal from the PMC ECU is completely suppressed when connected (both with and without additional resistors).

p.s. Inside the Transceiver, the RMI signal input is connected to +12V via a current source and a diode (and possibly another resistor and diode).

 

[Rakesh Suresh]

It would be useful to determine (photo) the nominal value of the resistance that is connected to pin 3 of the NE555 microcircuit on the simulator board. And determine what its other output is connected to (to GND or to +12V).

I think you forgot to link the photo? I didnt fully understand your question, but here are some details that may be helpful.

Details of the NE555 board: https://www.amazon.com/gp/customer-...ef=cm_cr_dp_d_rvw_ttl?ie=UTF8&ASIN=B018INS9QM


Resistances:
VCC to GND - 1.5K
VCC to OUT - 0.86M
OUT to GND - 0.85M

Here is a close up pic of the timer

 

[alflash]

Shall we check the heater control when connected with an external 2kOhm (not 10 kOhm) resistor?
Note: On the board, the generator output is connected to 12V via a 1.5kOhm resistor (152) and a LED.
The previous photo shows the diagram of the input circuits of the LIN transceiver RMI signals.


Attachments

 

[Rakesh Suresh]

Shall we check the heater control when connected with an external 2kOhm

Same behavior as earlier, although the amplitude is a bit higher. https://1drv.ms/v/s!AoMSicNQxi7y5y2rIktK4-8Ykyym

 

[Rakesh Suresh]

Is there any value in testing by connecting pwr directly to 12v battery positive terminal. That is another difference compared to the simulator.

 

[alflash]

Same behavior as earlier, although the amplitude is a bit higher. https://1drv.ms/v/s!AoMSicNQxi7y5y2rIktK4-8Ykyym

Are the oscilloscope probes connected to an external resistance?
What is its resistance value?

I have never directly connected the supply voltage to the information inputs. And I do not advise others to do this. Cancelled due to misunderstanding of the question, sorry.

In addition, high voltage at the RMI input is when heating is not needed*.
And this is shown in the form of oscillograms with a correct cabin heating system (https://www.myrav4ev.com/threads/charging-stopped-due-to-system-malfunction.2692/page-2#post-31850)

*For example, when the outside temperature is higher than the required/set one.

 

[Rakesh Suresh]

Are the oscilloscope probes connected to an external resistance?
What is its resistance value?

It's 1.98K. Yes, probes are connected to it.
Should we go even lower on the resistance in the next test?

My earlier question was if we should connect the pwr to positive terminal to rule out the possibility that ecu isn't able to supply enough current to pwr, but given pwr doesn't see a voltage drop, this test won't be valuable.

 

[alflash]

I assume that there is no need to reduce it below 2kOhm, since we do not know the permissible load capability of the PMC ECU output.

Excuse me, but I do not understand the question. I base it on the fact that with all these checks of heater control from the generator and when checking control from the PMC ECU with an external resistor between the RMI and PWR contacts, the heater is powered through the PWR contact.
https://alflash.com.ua/2019/to_rav4ev/cab_heat_w2.png
Please describe the question in other words.

 

[Rakesh Suresh]

My earlier question was if we should connect the pwr to positive terminal to rule out the possibility that ecu isn't able to supply enough current to pwr, but given pwr doesn't see a voltage drop, this test won't be valuable.

Sorry, please ignore this question. I got the answer.

Please describe the question in other words.

Should we go even lower on the resistance in the next test?

Should we try with a resistance lower than 2Kohm? May be 1Kohm? Or should I try using a potentiometer and gradually lower the external resistance till the the peak of pwm increases?

 

[alflash]

I think that reducing to 1 kOhm is useless.
But it's up to you to decide.