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sorry can no longer hear any clacks when turning key to start.
Normally there are multiple clacks, (negative contactor and pre-charge contactor, then a delay, then pre-charge contactor dropping out and positive contactor engaging) are you sure you're not hearing any at all? That would suggest quite a different problem of the ECU not even pulling in the contactors at all.

Have you tried disconnecting the HV cables to the PTC heater and A/C compressor as a quick test to rule out an insulation breakdown or fault in those? These are the two connectors at the front of the battery pack separate from the cable going to the MCU, and you only need the underbelly plastic covers off to get at them.

P1A15 means the high voltage (measured at the MCU I think) failed to rise to the expected voltage within the expected time period of a few hundred milliseconds during pre-charge.

There are many possible causes for that including -

1) Contactor didn't close at all due to the 12v feed to the contactors not being applied. If you really don't hear any clicks this could be your situation, in which case start tracing the control signals from the ECU. (Are the i-Miev circuit diagrams adequate for this?)

2) Burnt contactor contacts or faulty pre-charge resistor. (Both inside the battery pack)

3) A parasitic load on the HV voltage lines beyond the contactors - this could be in the PTC heater, A/C compressor, MCU or OBC. The PTC heater and A/C compressor can be isolated as above, and it's also possible to isolate the OBC DC/DC converter by removing the 20 amp fuse in the MCU inspection hatch at the top. It wouldn't take much load for the pre-charge resistor and parasitic load to form a voltage divider which prevents the target voltage being attained during pre-charge.

4) A fault with voltage sensing in the MCU, where it detects a lower than true voltage. We've seen a couple of examples of this on my-imev.com and there is suspicion that the voltage divider resistors may be drifting in value. I think one person padded the top divider resistor with a high value and managed to resolve their issue that way.
 

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Normally there are multiple clacks, (negative contactor and pre-charge contactor, then a delay, then pre-charge contactor dropping out and positive contactor engaging) are you sure you're not hearing any at all? That would suggest quite a different problem of the ECU not even pulling in the contactors at all.

Have you tried disconnecting the HV cables to the PTC heater and A/C compressor as a quick test to rule out an insulation breakdown or fault in those? These are the two connectors at the front of the battery pack separate from the cable going to the MCU, and you only need the underbelly plastic covers off to get at them.

P1A15 means the high voltage (measured at the MCU I think) failed to rise to the expected voltage within the expected time period of a few hundred milliseconds during pre-charge.

There are many possible causes for that including -

1) Contactor didn't close at all due to the 12v feed to the contactors not being applied. If you really don't hear any clicks this could be your situation, in which case start tracing the control signals from the ECU. (Are the i-Miev circuit diagrams adequate for this?)

2) Burnt contactor contacts or faulty pre-charge resistor. (Both inside the battery pack)

3) A parasitic load on the HV voltage lines beyond the contactors - this could be in the PTC heater, A/C compressor, MCU or OBC. The PTC heater and A/C compressor can be isolated as above, and it's also possible to isolate the OBC DC/DC converter by removing the 20 amp fuse in the MCU inspection hatch at the top. It wouldn't take much load for the pre-charge resistor and parasitic load to form a voltage divider which prevents the target voltage being attained during pre-charge.

4) A fault with voltage sensing in the MCU, where it detects a lower than true voltage. We've seen a couple of examples of this on my-imev.com and there is suspicion that the voltage divider resistors may be drifting in value. I think one person padded the top divider resistor with a high value and managed to resolve their issue that way.
Many thanks for the replies.

In the process of eliminating the many possible causes, I'm going to energise each of the 3 main traction battery pack contactors individually NOT in sequence to confirm that the 3 contactors (negative, precharge and main positive) are not faulty and that the pre-charge resistor is not open circuit. If these all check out OK, then the fault must lie with the EVECU, its supply circuit, an HV fault (leakage) in aircon compessor, or PTC heater, or OBC OR a measuement fault within the MCU-Inverter.

Whilst energising the 3 main traction battery contactors, I will have the service plug removed and Voltage will be recorded across the battery half pack.

Does anyone know of the polarity of the Manual Disconnect Service plug SOCKET (ie the bit that stays in the car). Photo of the service socket is attached show the two rectangular sockets and the microswitch contacts

So that I don't generate
 

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Many thanks for the replies.

In the process of eliminating the many possible causes, I'm going to energise each of the 3 main traction battery pack contactors individually NOT in sequence to confirm that the 3 contactors (negative, precharge and main positive) are not faulty and that the pre-charge resistor is not open circuit. If these all check out OK, then the fault must lie with the EVECU, its supply circuit, an HV fault (leakage) in aircon compessor, or PTC heater, or OBC OR a measuement fault within the MCU-Inverter.

Whilst energising the 3 main traction battery contactors, I will have the service plug removed and Voltage will be recorded across the battery half pack.

Does anyone know of the polarity of the Manual Disconnect Service plug SOCKET (ie the bit that stays in the car). Photo of the service socket is attached show the two rectangular sockets and the microswitch contacts

So that I don't generate
Another image of the CZero Manual Service Disconnect (socket side permanently attached to vehicle)
 

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Many thanks for the replies.

In the process of eliminating the many possible causes, I'm going to energise each of the 3 main traction battery pack contactors individually NOT in sequence to confirm that the 3 contactors (negative, precharge and main positive) are not faulty and that the pre-charge resistor is not open circuit. If these all check out OK, then the fault must lie with the EVECU, its supply circuit, an HV fault (leakage) in aircon compessor, or PTC heater, or OBC OR a measuement fault within the MCU-Inverter.

Whilst energising the 3 main traction battery contactors, I will have the service plug removed and Voltage will be recorded across the battery half pack.

Does anyone know of the polarity of the Manual Disconnect Service plug SOCKET (ie the bit that stays in the car). Photo of the service socket is attached show the two rectangular sockets and the microswitch contacts

So that I don't generate
There is also the possibility of HV cable faults or the main traction battery fuse. However If I get the main traction battery 1/2 pack voltage with contactors energised that would eliminate these as causes too!
 

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Discussion Starter #26
Hi guys. See there's been quite a bit of activity on this thread since yesterday!

Went to move the car today and, whilst it started, it went into turtle mode and pretty much failed to proceed. Read the live data from hobdrive and it showed that the capacitor voltage (when starting) was higher than the battery voltage. This was accompanied by some new dtcs.

My thinking is that my 2MOhm resistor was adequate yesterday (when things were a little bit warmer).

Propose to use a 5MOhm trimming pot to 'adjust' the capacitor voltage back into range. Think it would be wise to route the pot wiring up to the upper plenum so I can easily adjust if I'm out.

Welcome anybody's thoughts on this proposal.

Screenshot_20210131_163948_hobdrive.android.jpg y Screenshot_20210131_164426_hobdrive.android.jpg Screenshot_20210131_194955_com.android.chrome.jpg
 

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Hi guys. See there's been quite a bit of activity on this thread since yesterday!

Went to move the car today and, whilst it started, it went into turtle mode and pretty much failed to proceed. Read the live data from hobdrive and it showed that the capacitor voltage (when starting) was higher than the battery voltage. This was accompanied by some new dtcs.

My thinking is that my 2MOhm resistor was adequate yesterday (when things were a little bit warmer).

Propose to use a 5MOhm trimming pot to 'adjust' the capacitor voltage back into range. Think it would be wise to route the pot wiring up to the upper plenum so I can easily adjust if I'm out.

Welcome anybody's thoughts on this proposal.

View attachment 140330 y View attachment 140332 View attachment 140333
Hi where did you solder the resistor? I couldnt seem to open your picture. Seems to prove it is the voltage divider that is failing although having the variable resistor seems like an ongoing inconvenience. Is the voltage divider replaceable with one from a dead car or is it part of a larger component?

Cheers.
 

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Discussion Starter #28
The voltage sensing circuit is part of the board that's in the bottom plenum of the inverter. Problem is, it's coded to the car (not insurmountable). Bigger issue is that there aren't any available at the moment.

The variable resistor would be trimmed to the required value. I'd hope it wouldn't need to be adjusted regularly unless the caps on the voltage sensing circuit deteriorate further.

Resistor soldering location below- it's on the second leg of the IC as per the thread on the imiev forum.
140402
 

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The voltage sensing circuit is part of the board that's in the bottom plenum of the inverter. Problem is, it's coded to the car (not insurmountable). Bigger issue is that there aren't any available at the moment.

The variable resistor would be trimmed to the required value. I'd hope it wouldn't need to be adjusted regularly unless the caps on the voltage sensing circuit deteriorate further.

Resistor soldering location below- it's on the second leg of the IC as per the thread on the imiev forum. View attachment 140402
Over on mymive forum, havnt some people managed to replace the caps and op amps?
 

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Discussion Starter #30
There's talk of replacing the caps but don't think I have the dexterity, eyesight or equipment to replace the surface mounted components used- they're tiny!
 

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Over on mymive forum, havnt some people managed to replace the caps and op amps?
Which caps are we talking about? Tiny surface mount ones in the picture above? Are they going leaky upsetting the accuracy of the voltage divider? Seems like an odd failure mode for a ceramic chip capacitor.

Regarding trimming the voltage divider - it looks like Hobdrive has the ability to show the voltage measured by the BMS, (summed voltage of all cells from the CMU boards) and the voltage across the main filter cap in the MCU, (suspect voltage measuring circuit discussed here) in which case it should be possible to trim the divider so the two accurately match.

Currently with the extra resistor the voltage reading from the MCU is significantly higher than that reported by the BMS - this is probably going to set off alarm bells in the ECU...
 

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Discussion Starter #33
I'm not really that aware of the failure modes for these components, but that is certainly the suggestion that they leak and pull down the voltage.

Was purely going by what Kiev had said on the imiev forum- he sounded quite the authority on such things!

The fixed resistor (2MOhm) worked on Saturday, but since weather has got colder, the big cap voltage is now showing as >100% of the battery voltage. Ev ECU definitely doesn't like this fact!
 

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Apologies for not getting back with an update for ages. Finally got my inverter board back from the electronics place who had advised there was nothing wrong with it that they could find but said that there might be something that is not working in circuit.

So, in a bit of desperation, I soldered in a 2MOhm resistor as per the attached photo. Pleased to say that upon clearing the codes with hobdrive, the car now goes into Ready! Very chuffed!

Big thanks to everyone that contributed their experience and knowledge (particularly Eddie).
Thank you for the update, and the good news that you have solved the problem!

Hi Eddie,do you have an iMiev or one of the PSA clones. For the PSA clones, I think the U1113 code is permanent and non fatal because they they don't have the remote.
Thank you for the info about the U1113 code.
I have a 2012 Peugeot iOn as my daily driver ( and also a 2001 Citroen Berlingo Electrique van ). The iOn is fine, apart from having 80k miles, a 41-mile range in winter, and the usual rust under the back end & brake pipes.

Inspired by this thread, I recently acquired a non-running C-Zero with the P1A15 error. Along with it came a written-off iOn as a "spares" car. The C-Zero is ex-Edinburgh Police. It developed the fault before having it's first MOT, i.e. over 5 years ago, and despite the involvement of Mitsubishi Japan it has never been fixed. I am looking forward to the challenge!

Hi guys. See there's been quite a bit of activity on this thread since yesterday!

Went to move the car today and, whilst it started, it went into turtle mode and pretty much failed to proceed. Read the live data from hobdrive and it showed that the capacitor voltage (when starting) was higher than the battery voltage. This was accompanied by some new dtcs.

My thinking is that my 2MOhm resistor was adequate yesterday (when things were a little bit warmer).

Propose to use a 5MOhm trimming pot to 'adjust' the capacitor voltage back into range. Think it would be wise to route the pot wiring up to the upper plenum so I can easily adjust if I'm out.

Welcome anybody's thoughts on this proposal.

View attachment 140330 y View attachment 140332 View attachment 140333
Again, thank you for the update, and the not-so-good news!
Although it is most likely that the ground fault and leakage detected errors are caused by the measured voltage divergence, are you sure that all connections and board mountings for the refitted inverter boards are secure?
Regarding the 5Meg trimpot: I would suggest mounting it close to the chip ( where the 2M fixed resistor was ), but epoxy a piece of semi-stiff plastic tube ( e.g. the ink tube from a BIC ballpoint ) to the adjuster and lead it out through a small hole drilled in the side of the inverter enclosure.
 

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Normally there are multiple clacks, (negative contactor and pre-charge contactor, then a delay, then pre-charge contactor dropping out and positive contactor engaging) are you sure you're not hearing any at all? That would suggest quite a different problem of the ECU not even pulling in the contactors at all.

Have you tried disconnecting the HV cables to the PTC heater and A/C compressor as a quick test to rule out an insulation breakdown or fault in those? These are the two connectors at the front of the battery pack separate from the cable going to the MCU, and you only need the underbelly plastic covers off to get at them.

P1A15 means the high voltage (measured at the MCU I think) failed to rise to the expected voltage within the expected time period of a few hundred milliseconds during pre-charge.

There are many possible causes for that including -

1) Contactor didn't close at all due to the 12v feed to the contactors not being applied. If you really don't hear any clicks this could be your situation, in which case start tracing the control signals from the ECU. (Are the i-Miev circuit diagrams adequate for this?)

2) Burnt contactor contacts or faulty pre-charge resistor. (Both inside the battery pack)

3) A parasitic load on the HV voltage lines beyond the contactors - this could be in the PTC heater, A/C compressor, MCU or OBC. The PTC heater and A/C compressor can be isolated as above, and it's also possible to isolate the OBC DC/DC converter by removing the 20 amp fuse in the MCU inspection hatch at the top. It wouldn't take much load for the pre-charge resistor and parasitic load to form a voltage divider which prevents the target voltage being attained during pre-charge.

4) A fault with voltage sensing in the MCU, where it detects a lower than true voltage. We've seen a couple of examples of this on my-imev.com and there is suspicion that the voltage divider resistors may be drifting in value. I think one person padded the top divider resistor with a high value and managed to resolve their issue that way.
OK, back to basis for me. I connected an external battery, bolted large good battery straps.

Connected up a 2 channel scope.
Channel A connected to the +terminal of the 12v battery
Channel B connected to the EV-ECU ignition switched supply (light blue wire pin 3 - 36V connector)

Battery voltage started out at 12.1 volts with ignition on (its cold out there). It had been charged 4 hours previously.

Transient voltage at 50ms sampling time was 11.84v on channel A, 10.73v on channel B

Thats a 1.1v drop at say 5amps???? that would make it 0.2ohms resistance in the circuit (all the connections plus small gauge wiring. Seem excessive?
Secondly, with the voltage on the switched supply to the EV-ECU going this low, could it lead to false measurements of the charging condensor (time or voltage) back at the MCU? Has anyone got any comparative data?

Many thanks
 

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I'm not really that aware of the failure modes for these components, but that is certainly the suggestion that they leak and pull down the voltage.

Was purely going by what Kiev had said on the imiev forum- he sounded quite the authority on such things!

The fixed resistor (2MOhm) worked on Saturday, but since weather has got colder, the big cap voltage is now showing as >100% of the battery voltage. Ev ECU definitely doesn't like this fact!
Hi Civjdh, not sure if you have come across this German fo
I'm not really that aware of the failure modes for these components, but that is certainly the suggestion that they leak and pull down the voltage.

Was purely going by what Kiev had said on the imiev forum- he sounded quite the authority on such things!

The fixed resistor (2MOhm) worked on Saturday, but since weather has got colder, the big cap voltage is now showing as >100% of the battery voltage. Ev ECU definitely doesn't like this fact!
Hi Civjdh, not sure if you have come across this German forum discussing same P1A15 issue.
P1A15 Fehler - Problem gelöst - C-ZERO, i-MiEV, iON - Allgemeine Themen • C-ZERO, i-MiEV, iON - Elektroauto Forum (goingelectric.de)
I gather from that discussion that the problem might sometimes lies in the offset drift of the A/D voltage measurement circuit (transformer residual magnetism) and that maybe reprogramming the A/D is possible. Hopefully someone else can read the German thread and better understand the cure to the P1A15 common problem.
regards
 

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Discussion Starter #37
Hi Freddy, had a read of it courtesy of Google translate and there's definitely some useful info in there. Never thought in my life that I'd be considering recalibrating a integrated circuit.... But what can I say, EVs not only save you money, but they also teach you about electronics!
 

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I can speak and read German, but cannot make much sense of the comments in that thread. It doesn't help that the "solution" is only being passed on by private messages.

The discussion about the fault being caused by an over-saturated transformer core that has become permanently magnetized, and which could be fixed by demagnetisation, makes no sense at all. There are transformers on the hybrid daughter-board, perhaps for voltage isolation, but they are pulse transformers with ferrite cores, and this highly permeable material has negligible remanence.

The AD8677 Op-Amp used in the hybrid circuit is already a device with ultra-low offset, ( i.e. it knows when the two inputs really are equal ), and this offset is stable against variations in temperature and time ( i.e. ageing ). Rather than the "MyImiev Forum solution" of trimming the input voltage divider to alter the ratio of measured voltage vs. reference voltage, this new solution biases the output of the Op-Amp by using a 20k variable resistor to offset ( skew ) the pre-existing internal balance in the chip between the two inputs. It is like the old grocer's trick of casually resting one hand on the scales whilst weighing your purchase....
 

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P1A15 error update.

With a brand new fully charged battery, dome some further testing.

Going from 'ON" to "START" position with the key, the Negative Contactor switches on, then the precharge, the contactors are clacking, the dash warning HV light comes on
On a 2 channel scope I can see all this.
If I connect the two channels to the Precharge Contactor coils driver output from EVECU and the other channel to the Main Positive Contactor, its never energised. You can see that on attached pic. The Precharge Coil output has a brief pulse then a much longer On period. Is this correct?
 

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IMG_20210220_131251.jpg
IMG_20210220_131251.jpg
P1A15 error update.

With a brand new fully charged battery, dome some further testing.

Going from 'ON" to "START" position with the key, the Negative Contactor switches on, then the precharge, the contactors are clacking, the dash warning HV light comes on
On a 2 channel scope I can see all this.
If I connect the two channels to the Precharge Contactor coils driver output from EVECU and the other channel to the Main Positive Contactor, its never energised. You can see that on attached pic. The Precharge Coil output has a brief pulse then a much longer On period. Is this correct?
Sorry the Main Positive coil driver is never energised
 
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