[ The P1A15 Troubleshooting Thread ] No READY. P1A15 error. Condenser charge timeout.
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You might have a look at this topic for various options, and there's a concise video in the last post in that thread: http://myimiev.com/forum/viewtopic.php?f=13&t=1626gczero said:
Hi guys
Is it possible to share the schematic for the ISA board and also where to get access to these components that need to changed, also an explanation of how it works would be great for better understanding, thanks in advice
If i just replace this hybrid board from another MCU is it a VIN number conflict then?
Is it possible to share the schematic for the ISA board and also where to get access to these components that need to changed, also an explanation of how it works would be great for better understanding, thanks in advice
If i just replace this hybrid board from another MCU is it a VIN number conflict then?
Taupilz said:Hi guys
Is it possible to share the schematic for the ISA board and also where to get access to these components that need to changed, also an explanation of how it works would be great for better understanding, thanks in advice
If i just replace this hybrid board from another MCU is it a VIN number conflict then?
Howdy Taupilz,
We can see your post okay, there is no viewing problem. Maybe some history of your issues would help get some more folks involved.
There would be no VIN conflict if all you replace is the hybrid board.
Are you sure that this board is defective in your car--how did you determine this? This issue is quite a big puzzle to several folks so every little bit helps.
I have not removed this board from my car to trace the schematic, maybe someone else has but I have never seen it posted.
There are some nice pictures posted here: http://myimiev.com/forum/viewtopic.php?f=23&t=4225&start=50#p40953
Hi again, well my status is that both the PTC heater and AC compressor was already disconnected when i bought this car, it has this P1A15 error code and will not go to ready, its not possible either to charge the car, only a red flickering socket symbol is showing up in the display.
I am not sure whats wrong, but what i read here is that this circuit measuring the voltage and gives feed back to the EV ECU could be the problem. When i connect my DTC reader (Icarsoft CR Pro) i can see that the precharge condenser voltage rises up to 342V and then fall down to 2V, the main contactors try to close, but opens after a second or so, If you guys could give some advice what to check first i will appreciate that very much.
I am not sure whats wrong, but what i read here is that this circuit measuring the voltage and gives feed back to the EV ECU could be the problem. When i connect my DTC reader (Icarsoft CR Pro) i can see that the precharge condenser voltage rises up to 342V and then fall down to 2V, the main contactors try to close, but opens after a second or so, If you guys could give some advice what to check first i will appreciate that very much.
With the icarsoft scan tool you can also read the voltage of all the cells to access their health, and read the total voltage of the pack to compare with the 342 VDC that you measured for the buss capacitor during the attempt to start.
The P1A15 DTC gets set if the capacitor voltage is too slow to come up or never reaches the pack voltage value. So it could be due to some leakage or load thru the AC or heater, or due to a measurement signal error either on the main circuit board or the little hybrid amplifier board.
Your test data indicates that the main contactors are working since you were able to read the 342 VDC at the buss capacitor, the DTC got set and caused the EV-ECU to open the contactors and the voltage was drained off back down to 2V.
Maybe you can try to clear the error codes with the scan tool and try to start, then read all the DTCs that are set and post them.
The P1A15 DTC gets set if the capacitor voltage is too slow to come up or never reaches the pack voltage value. So it could be due to some leakage or load thru the AC or heater, or due to a measurement signal error either on the main circuit board or the little hybrid amplifier board.
Your test data indicates that the main contactors are working since you were able to read the 342 VDC at the buss capacitor, the DTC got set and caused the EV-ECU to open the contactors and the voltage was drained off back down to 2V.
Maybe you can try to clear the error codes with the scan tool and try to start, then read all the DTCs that are set and post them.
Taupilz said:
Since this car has an unknown previous history of repair attempts then nothing can be assumed as okay without checking and verifying, e.g. the wiring harness and connections between the EV-ECU and BMU, etc. There are multiple serious issues with overlapping extent between control units.
The U1100 indicates no CAN buss communication received by BMU from the EVECU, and the U1922 says that the backup K-Line communication between these two is not working either. Most likely a harness or connector issue but could be failed control units. I've never seen the failed K-line code before, and I think it is quite serious.
The P1AA7 is a new code on the forum, it indicates the signal sent by the EV-ECU through the CAN cannot be received by the BMU. The fail-safe or backup for this is to use the K-Line, but that doesn't seem to be working and threw the U1922. The probable causes are failed CAN buss, EV-ECU or BMU.
ref. Factory Service Manual P1AA7 page
The P1A15 is a MCU time-out code that may be set due to defective CAN buss or EV-ECU wiring or failure. I think it is a secondary issue considering the other codes, i.e. if the other codes are fixed then this code will go away. It is more likely an issue under the rear seat than a defect in the MCU in my opinion, but it could be that the MCU issue occurred first and subsequent attempts to repair have mangled the wiring under the seat such that additional codes are being thrown. If the communications were okay then only the MCU code would appear.
You will need to take good notes of what you check, find and verify in order to ring all this out.
coulomb
Well-known member
Yes, certainly. If the condenser doesn't hold battery voltage, then the charrger can't work, you can't drive the car, and you can't use the heater or air conditioner. The "condenser" (such a quaint old term, it reminds me of tube radios) is basically the sum of all the capacitors in the motor controller, charrger output, etc. No condenser voltage, no high voltage bus, no funTaupilz said:
hi
Thanks a lot for all the good information, i will try to measure the voltage of the large capacitor with a multimeter and compare the voltage with the battery voltage to see if there is any difference between those. Maybe the capacitor has a decreased capacitance and is not 800 microfarad due to aging? if they are the same, and still the EV-ECU receives only 342, when the battery voltage is 354 at the moment, maybe i can conclude that there is something wrong with the measuring circuit.
I imagine that something similar is going on in the measuring circuit, the op-amp comparator receives about 4VDC (reduced by a factor of 90) from the capacitor, compares it with the 4VDC from the battery, and if the resulting voltage is different from 0V the output is set to "1" and then throw the P1A15 code.
is it a good idea, or waste of time??
i also see that user czerodk has posted a graph from an oscilloscope with exactly the same values that i have, 342V when charging, and 2V after discharging, strange or?
Thanks a lot for all the good information, i will try to measure the voltage of the large capacitor with a multimeter and compare the voltage with the battery voltage to see if there is any difference between those. Maybe the capacitor has a decreased capacitance and is not 800 microfarad due to aging? if they are the same, and still the EV-ECU receives only 342, when the battery voltage is 354 at the moment, maybe i can conclude that there is something wrong with the measuring circuit.
I imagine that something similar is going on in the measuring circuit, the op-amp comparator receives about 4VDC (reduced by a factor of 90) from the capacitor, compares it with the 4VDC from the battery, and if the resulting voltage is different from 0V the output is set to "1" and then throw the P1A15 code.
is it a good idea, or waste of time??
i also see that user czerodk has posted a graph from an oscilloscope with exactly the same values that i have, 342V when charging, and 2V after discharging, strange or?
There is a small cover on the MCU that allows access to the HV terminals, but I don't think that a multimeter will give any meaningful readings--you probably need an oscilloscope to see the rise time.
There is another 220uF of capacitance in the OBC that is also connected to that same point. There is a pre-charge resistor in the pack that limits the surge current during turn-on.
The question is whether there is some extra drain or leakage that is pulling down the HV at startup, or if it is a measurement signal issue.
Wonder what czerodk did to fix his problem?
There is another 220uF of capacitance in the OBC that is also connected to that same point. There is a pre-charge resistor in the pack that limits the surge current during turn-on.
The question is whether there is some extra drain or leakage that is pulling down the HV at startup, or if it is a measurement signal issue.
Wonder what czerodk did to fix his problem?
coulomb
Well-known member
If it has, it will only make the pre-charge process faster. It may have excess leakage, but I don't expect that from a film capacitor (if that's what it is).Taupilz said:
I note that there is always some leakage / power drawn by the high voltage circuit, so the capacitor/condensor voltage will never reach exactlt the battery voltage. I believe that the pre-charge resistor is 24Ω, which is pretty low, so it should reach very close to the battery voltage. I don't know how close it typically gets, or how close it has to be before the condenser charge timeout trouble code is avoided. I would expect at least a 5% gap; it takes some 3 time constants for a capacitor to charge to 95% of the input voltage via a resistor, and that's neglecting any loads/leakage. Though the time constant here is small, around 25 ms (assuming a total bus capacitance of just over 1000 μF, or 1 mF).
I would think that it's just a buffer circuit, so that other parts of the circuit don't load the high value resistors. Often, both the positive and negative from the thing being measured (the capacitors in this case) are subtracted, so it's a differential amplifier. So the output is proportional to the difference between the inputs, which means proportional to the capacitor voltage. The comparison between battery and capacitor voltage would then be digitally inside the ECU (possibly the BMU but I don't know). But you may be right, it might be measuring the voltage difference between capacitor and battery (so across the main positive contactor, I think).
I really don't know; you'll quite possibly learn something, but be very careful with safety. You probably want a multimeter that can record maximum and minimum voltages, because pre-charge is over in well under one second. It might still not be fast enough to catch the true maximum. You will probably need special high voltage probes to use an oscilloscope safely.
As Kiev has stated, the interesting question is why it goes to 2 V after the charge. Is it because the ECU decided the capacitor voltage wasn't high enough, so the pre-charge is aborted, or because the capacitor voltage was fine (maybe 342 V is high enough) and the voltage collapses because the main contactor doesn't work? [ Edit: duh, see next post. ] The latter could be because of burned contacts, failed coil, no drive to the coil, or wiring to the coil. Or it could be a failed measurement. I would not expect the capacitor voltage to collapse very quickly if the main contactor fails, unless some HV load comes on. The bleed resistors probably take at around 30 seconds to bleed the capacitor voltage to a safe level, and minutes to drop down to 2 V,
coulomb
Well-known member
Duh. The capacitor voltage is obviously declared too low (whether it really is or not), because of the trouble code. So forget what I said about the main contactor not working.
A final thought: maybe when that trouble code is asserted, the EV ECU does something to quickly discharge the DC bus: perhaps it can turn on a fast discharger, or it does something to make the motor controller use a pulse of current, that sort of thing. If so, the 2V is not a symptom of a problem, just an expected result when that trouble code comes up.
My apologies if this was obvious, and I was just being thick.
A final thought: maybe when that trouble code is asserted, the EV ECU does something to quickly discharge the DC bus: perhaps it can turn on a fast discharger, or it does something to make the motor controller use a pulse of current, that sort of thing. If so, the 2V is not a symptom of a problem, just an expected result when that trouble code comes up.
My apologies if this was obvious, and I was just being thick.
size of the capacitors (С225,С227,С229,С231) [there is not a C291]
the dimensional size of the caps is "0805"
C227,229,231 are yellow-brown ceramics with a value of about 390 nF or .39 uF. They are all in parallel and the total across them measured about 1.22uF
C225 has a pinkish color of the ceramic (may indicate tolerance or voltage rating) and looks the same as some other caps on the board that had a measured value of about 4.7pF.
This cap is connected across the Gate to Source of FET2 [NEC 2SK3116] and i measured 2.4 nF, which is likely due to the meter charging up the FET (the Gate charge is listed as 26nC on datasheeet).
Resistor size,accuracy and power (R211,R212,R216,R219,R220,R221)
R211-220 (total of 6 in series) these are blue colored (1% tolerance?) 100k resistors, size "1206"
R221, 223,225 are blue colored 6.8k resistors, size "0805"
Let us know if you find any damaged or different part values when you take them off the board.
the dimensional size of the caps is "0805"
C227,229,231 are yellow-brown ceramics with a value of about 390 nF or .39 uF. They are all in parallel and the total across them measured about 1.22uF
C225 has a pinkish color of the ceramic (may indicate tolerance or voltage rating) and looks the same as some other caps on the board that had a measured value of about 4.7pF.
This cap is connected across the Gate to Source of FET2 [NEC 2SK3116] and i measured 2.4 nF, which is likely due to the meter charging up the FET (the Gate charge is listed as 26nC on datasheeet).
Resistor size,accuracy and power (R211,R212,R216,R219,R220,R221)
R211-220 (total of 6 in series) these are blue colored (1% tolerance?) 100k resistors, size "1206"
R221, 223,225 are blue colored 6.8k resistors, size "0805"
Let us know if you find any damaged or different part values when you take them off the board.
