Clubjazz - Honda Jazz & HR-V Forums

Honda Jazz Forums => Honda Jazz Mk4 2020 - => Topic started by: alchemistjazz on September 15, 2023, 07:57:48 PM

Title: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: alchemistjazz on September 15, 2023, 07:57:48 PM: Hi there,

I have a Honda Jazz 2021 - Hybrid.

I have been away for about 6 weeks and left my car, and now I am getting the message: High Voltage Battery Charge Too Low - Vehicle Cannot Start with all warning lights when I attempt to start.

The 12v battery was dead, so have tried to charge it.

The EV battery is showing 0 bars. I have tried to jump start the car but nothing much seems to happen.

Any suggestions would be appreciated.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Marco1979 on September 15, 2023, 08:28:31 PM: Strange! There should not be a drain on the high voltage battery, so maybe the 12v was so low that it cannot measure the high voltage correctly?

You might be able to reset it somehow when 12v is charged again. Or call Honda assistance.

Good luck; keep us posted.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Whiteshark on September 15, 2023, 09:05:06 PM: Likewise, that is a most unusual situation. I think I would call Honda Assist, but would be most interested to know the cause. Good luck
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Kremmen on September 16, 2023, 05:31:44 AM: What was the car usage before the 6 week break ?

If it was left on say, 3 bars, that may have been low enough.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Lord Voltermore on September 16, 2023, 06:52:27 AM: Oh dear, that is unusual. Even if Honda Assistance or the dealer are able to get the car started fairly easily and send you on your way for now I'd want to ensure the HV battery etc is thoroughly checked while its still under warranty.

I notice the car has done 28000 miles, but has it recently had little use in addition to the 6 weeks you mentioned? eg has the car been DRIVEN for at least 30 minutes in the last 3 months? ( There is a warning about this in the handbook, and on a label under the bonnet.) I believe the HV battery needs to go through some charge and discharge cycles during this 30 minute drive. It may not be enough just to start the car and let the engine run on the driveway.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Marco1979 on September 16, 2023, 09:12:03 AM: I would be intrigued to know the cause and how to avoid it. Living in a 20 mph zone, the car is always down to 2 bars when I park. The longest I left it unused was probably 2.5 weeks.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Whiteshark on September 16, 2023, 09:29:51 AM: From my experience leaving unused for a long period is not necessarily the problem. There is much info on here, plus manuals etc.
We left our hybrid jazz for over 7 weeks unused in April/ May this year, but …….. it was advised on here to insure the 12v battery was fully charged before we left, and that is what I did using a CTek. I do not remember, because I didn’t check what the high voltage battery charge was like before we departed, although the vehicle is used regularly, but weekly, not daily, and does 4K per annum.
What I do know is that on return, everything worked perfectly
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: coravel on September 16, 2023, 11:05:14 AM: Same thing happened to me when I returned from a 3 month holiday. The car was completely dead so I called out Honda Assist (the AA) and the mechanic charged up the 12v battery for 20 minutes which allowed the car to start and then told me to drive it for half an hour to charge up the high voltage battery. No problems with it since and the battery was found to be in good condition when tested during the first service.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: alchemistjazz on September 16, 2023, 11:31:22 AM: I did try and charge the 12v battery, and then start but it didn't work.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: John Ratsey on September 16, 2023, 02:16:06 PM: Quote from: coravel on September 16, 2023, 11:05:14 AM
Same thing happened to me when I returned from a 3 month holiday.
Did you have a low HV battery problem as well as a dead 12V battery?

Given that in normal operation the vehicle won't let the HV battery drop below 2 bars on the gauge (ie about 20% charge), the HV battery is completely disconnected when the vehicle is switched off and the self-discharge rate of lithium batteries is very low I have to wonder if there's a more fundamental problem with the problem HV battery. One possibility is that after 28k miles and innumerable partial charge/discharge cycles the car no longer knew where zero is on the battery as it never normally goes there (it does reach full charge when going down a long hill). And if the car has lost track of the empty point then the HV battery could have been only slightly above the low battery threshold when parked up.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Steve_M on September 16, 2023, 03:13:49 PM: A dealer will need to put the vehicle into maintenance mode, that allows the HV battery to use the reserve power (if there is any) to turn the engine over, the generator can then charge the HV battery. If there is no HV charge it will mean replacement of the HV battery.

Had there been any issues before the lay up period?
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: alchemistjazz on September 17, 2023, 02:22:18 PM: Haven't had any issues before.

Charged the 12v battery until it was fully charged. After a few attempts to start it, a voltmeter in the 12v cigarette lighter reads 8v, does that mean I need to replace the 12v battery?

Also if the HV battery is flat will a tow of the car allow it to re-generate a charge?
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Kremmen on September 17, 2023, 02:47:43 PM: 8v does indicate a dead 12v battery if that's immediately after a full charge

I think when towing, the front wheels must be off the ground
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: ahavoja on September 17, 2023, 08:02:31 PM: Quote from: alchemistjazz on September 17, 2023, 02:22:18 PM
Charged the 12v battery until it was fully charged. After a few attempts to start it, a voltmeter in the 12v cigarette lighter reads 8v, does that mean I need to replace the 12v battery?

Also if the HV battery is flat will a tow of the car allow it to re-generate a charge?

For a 12 V lead acid battery, about 13 V indicates fully charged battery, and 11 V would mean completely drained battery. So 8 V sounds like either it wasn't charged, or it's broken. If you have a multimeter, you can try checking the voltage directly from the battery terminals. Also while charging, the battery voltage should be higher, like 13 - 15 V. That way you can verify if the charger is working. It may take 10 or even 20 hours to fully charge a car battery.

Interesting idea, if the HV battery could be charged by towing the Jazz. In theory it would be the same as driving downhill and using regenerative braking in B mode to charge the battery. In the boot, behind the right wall there is a detachable towing hook. I suppose it attaches to the front of the Jazz, so that another car could be used to tow the Jazz with a rope.

Does the car allow you to switch to B gear, or is it stuck in parking gear?
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: alchemistjazz on September 17, 2023, 10:31:17 PM: The gear is stuck, but if I keep rocking the car, I am able to release it from parking.

While charging it went to 14.5V at the battery.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Kremmen on September 18, 2023, 06:16:44 AM: I wonder if the HV battery is OK but a completely dead 12v battery has confused the diagnostic ?

I've had many occasions where after trickle charging the 12v battery the battery meter has gone to 10 bars
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Steve_M on September 18, 2023, 07:10:27 AM: If you have charged the 12v battery, try getting it into maintenance mode, that should start the engine if the HV battery has reserve charge.

Same as other Honda models.

https://www.gen3insight.com/threads/maintenance-mode-in-3rd-gen-insight-and-2018-hah.4252/
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Whiteshark on September 18, 2023, 09:53:59 AM: Hi, is there any reason why you would not request Honda Assist. Whichever way you look at it, unless something untoward has happened of which we are not aware, you would be covered under warranty ?
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: alchemistjazz on September 18, 2023, 12:09:08 PM: I will be ringing them, but do I need to change the 12v battery first? or is that supposed to be covered?
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: mitchelln on September 18, 2023, 01:01:43 PM: Quote from: Whiteshark on September 18, 2023, 09:53:59 AM
Hi, is there any reason why you would not request Honda Assist. Whichever way you look at it, unless something untoward has happened of which we are not aware, you would be covered under warranty ?
Perhaps they were not aware that they had it. Horizon Honda didn't mention it at all when I bought our MK4 last year. No documentation, nothing. I assumed they'd dropped the scheme until I contacted Honda directly when I had trouble setting up the MyHonda app.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Whiteshark on September 18, 2023, 02:16:17 PM: I saw that is was a 21 model therefore fully covered under 3 warranty including Honda Assist. Whichever way you look at it the battery either is or is not covered, depending upon assessment, but the difference in battery cost from a main dealer is not necessarily much more than elsewhere.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: alchemistjazz on September 18, 2023, 05:41:49 PM: I was not aware of the Honda Assist till someone posted it here, thanks for that.
I was hoping like my previous cars, I would be able to get it working so that I learn for next time, but maybe it's not that with Electric cars.

I replaced the 12v battery just in-case, it read 1 bar for a while, and put it into Maintenance mode but was unable to get it started. So will revert to Honda Assist :)
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Whiteshark on September 18, 2023, 08:00:22 PM: Good luck and I’m sure like many of us , we will be most interested in the outcome.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: alchemistjazz on October 09, 2023, 09:16:14 AM: Hi All,

Thought I would post an update of my journey.
Called out Honda Assist, the AA came and they tried to jump start the car, they tried to read diagnostics but didn't find anything.

It was taken to a dealership who just rang saying they will carry out a diagnostic, when I said I was away for 2-3 weeks they started saying if that is the reason I may need to pay for the repair and £90 for diagnostics, they will come back to me.
Am I not allowed to take a holiday once I buy a Honda Jazz?
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: ColinB on October 09, 2023, 09:37:22 AM: Quote from: alchemistjazz on October 09, 2023, 09:16:14 AM
... I may need to pay ... £90 for diagnostics...

There does seem to be an increasing trend that you have to pay for the initial diagnostic, and if they confirm the defect and that rectification is covered by the warranty then the diagnostic cost should be refunded. Annoying, but I suppose it deters time-wasters who go to dealers with spurious "defects" that aren't (not suggesting that here at all, just commenting on the possible reason for the diagnostic charge).
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: GeoffW on October 11, 2023, 03:51:59 PM: Refuse in front of other customers to pay any charge for diagnostics on a car which is under warranty. It worked for me.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: alchemistjazz on October 11, 2023, 09:32:36 PM: They gave me a ring to say it the due to the 12v battery not being OEM, and needed changing. I told them to change it. Then I didn't hear from them, so rang them again, and they said changing the battery didn't work, so they have called in help from Honda Technical. So need to wait.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: coldstart on October 17, 2023, 09:41:04 PM: @alchemistjazz: I'm quite taken aback that it takes Honda over a month to get your Jazz up and running again!
Question: Are you absolutely positive that you properly switched of the car before your absence?
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: alchemistjazz on October 27, 2023, 06:35:04 PM: Had a nightmare with the dealer. So the dealer said it might be the HV battery and to test it I need to give them £1500 and if it is the battery then another £7000 to replace it.
So the dealer is saying the previous owner told them the car had a engine change, so the car has no warranty. (So a headache I need to follow-up on with the previous owner). But they can't give me any information on it.
I requested the car back, when the AA recovered the car at the dealership he saw damage on the car bumper where it has been hit by another vehicle and took pictures.

I told the dealership and they are denying it saying it might have already existed and they can't see anything hit it in their CCTV. I asked for the pre-inspection report and they said they couldn't carry one out conveniently due to the car's location and being a non-runner. Though they could tell me in needs 4 new tyres.

So back to the car:
So once I got the car back I have got a replacement HV battery and changed it over (DISCLAIMER: I am not telling anyone to do this without training and know how. SAFTEY FIRST)

After replacing the battery I had 7 bars and EV Ready sign the car started. I let it idle for few minutes and then started to reverse it where the HV battery went down from 7 to 0 bars. Then the car cut out.

The car will try and start for a few seconds if I try and start it before stalling.

Since I got the car back from Honda I have a new error on the screen 12V Battery not charging. (They fitted a new 12v Battery).

Is there a way to force the petrol engine to turn on? Could the fuel be contaminated or mis-fuelled?
Or could it be a alternator (AC-DC convertor) fault?

Before replacing the HV battery the HDS diagnostic was reporting the error: P06AF - Permanent.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Jazzyone on October 27, 2023, 07:27:06 PM: You can force engine to start. Switch on as normal and leave it in park. Depress the throttle and hold it down. After about 15 seconds the engine will start up. If you’ve got errors showing though it might stop it firing up.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Jazzik on October 27, 2023, 11:48:15 PM: Did you buy the car from a Honda dealer or from a private person?
Have you been informed by the seller that the car has undergone an engine change and the car has no warranty?
Was the engine change carried out by a Honda dealer?
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Marco1979 on October 28, 2023, 08:43:23 AM: An engine swap for a car this young and no warranty? If this would have happened to me I would bring the car back to where I bought it and would want my money back! Or demand that they solve the problem.
Good luck; you might need some legal advice!
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Marco1979 on October 28, 2023, 08:53:16 AM: I also remember that - because of the high currents - extra care should be taken when connecting HV components. Maybe, when swapping the engine, a connector makes a faulty connection causing a higher resistance? That would explain the instant drop in voltage and bars.
Disconnecting, thorough cleaning and reconnecting might help.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Kremmen on October 28, 2023, 09:21:51 AM: I'd be getting professional help
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Jazzik on October 28, 2023, 10:55:15 AM: Quote from: Marco1979 on October 28, 2023, 08:43:23 AM
An engine swap for a car this young and no warranty? If this would have happened to me I would bring the car back to where I bought it and would want my money back! Or demand that they solve the problem.
Good luck; you might need some legal advice!
I'm afraid that after this you really have a problem (https://www.cheesebuerger.de/images/midi/konfus/a014.gif) as for warranty:

Quote from: alchemistjazz on October 27, 2023, 06:35:04 PM
So back to the car:
So once I got the car back I have got a replacement HV battery and changed it over (DISCLAIMER: I am not telling anyone to do this without training and know how. SAFTEY FIRST)
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Whiteshark on October 28, 2023, 11:28:28 AM: I think I kinda guessed something wasn’t quite right about this from the very start. Hondas are generally bullet proof.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: alchemistjazz on October 28, 2023, 05:10:00 PM: I connected the Honda HDS diagnostics and it gave the same error: P06af.

In the diagnostics when I try and go to the IMA/Powertrain section it says "No communication with IMA".
Any clues what I should check? Which Fuses and Plugs?

I was not able to get the petrol engine started by holding down the gas pedal for 15 seconds.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Lincolnshire Rambler on October 28, 2023, 06:23:34 PM: I would expect any issues with the original engine and HV caused by a defect to be covered by the three year warranty. Of course if you run the car with a low oil warning and damage the engine then it’s your fault for not taking notice . Other than physical damage to the HV battery by the owner I don’t see them needing replacing . Anyone who obtains a HV battery and replaced it themselves would be expected to have a good understanding of the cars software and associated diagnostics. You tube has lots of good videos of experts fault finding EVs and hybrids ( mainly VW Audi ). These individuals are not main dealers but trade experts in the controlling computer tech . You can’t simply unbolt a HV battery and plug in a replacement one and expect it to work
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Jazzik on October 28, 2023, 08:58:56 PM: Quote from: Lincolnshire Rambler on October 28, 2023, 06:23:34 PM
You can’t simply unbolt a HV battery and plug in a replacement one and expect it to work

Not...? Not even when you own an alchemistjazz? (https://www.cheesebuerger.de/images/smilie/konfus/a015.gif)

(https://tse2.mm.bing.net/th?id=OIP.B4ii9PbQMioPdZxg_g1DbQHaE7&pid=Api&P=0&h=220)

I really wonder what the history of this Jazz is and whether topic starter was aware of it when he bought it..?
Hence my (unanswered) questions from October 27, 2023, 11:48:15 PM
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Lincolnshire Rambler on October 28, 2023, 09:06:25 PM: Magic wands and spells may help…to add to the alchemist way of doing things of course
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: alchemistjazz on October 28, 2023, 11:15:19 PM: Quote from: Jazzik on October 27, 2023, 11:48:15 PM
Did you buy the car from a Honda dealer or from a private person?
Have you been informed by the seller that the car has undergone an engine change and the car has no warranty?
Was the engine change carried out by a Honda dealer?

I got it via a auction was supposed to be a company car, was not aware it had a engine change before I bought it. The dealership said the engine change was done outside of the network.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Jazzik on October 28, 2023, 11:36:46 PM: So basically you've been cheated...(https://www.cheesebuerger.de/images/midi/traurig/a045.gif)
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Kremmen on October 29, 2023, 03:55:05 AM: I agree

An engine change on such a new car seems very odd and with the HV problems, more going on here

Bought a lemon
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: alchemistjazz on October 29, 2023, 08:31:15 AM: Quote from: Jazzik on October 28, 2023, 11:36:46 PM
So basically you've been cheated...(https://www.cheesebuerger.de/images/midi/traurig/a045.gif)
Quote from: Kremmen on October 29, 2023, 03:55:05 AM
I agree

An engine change on such a new car seems very odd and with the HV problems, more going on here

Bought a lemon

Yes you both are right.

Do you know which fuse would be related to the IMA, if I can communicate with that it might give me a bit more of an idea.

(https://www.insightcentral.net/cdn-cgi/image/format=auto,onerror=redirect,width=1920,height=1920,fit=scale-down/https://www.insightcentral.net/attachments/screenshot-2023-10-29-082544-png.106082/)

(https://www.insightcentral.net/cdn-cgi/image/format=auto,onerror=redirect,width=1920,height=1920,fit=scale-down/https://www.insightcentral.net/attachments/screenshot-2023-10-29-082615-png.106081/)

(https://www.insightcentral.net/cdn-cgi/image/format=auto,onerror=redirect,width=1920,height=1920,fit=scale-down/https://www.insightcentral.net/attachments/screenshot-2023-10-29-082635-png.106083/)
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: guest334 on October 29, 2023, 10:02:55 AM: Did you check the cars history for write off insurance issues eg vehicle check etc?
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: alchemistjazz on October 29, 2023, 01:05:38 PM: Quote from: olduser1 on October 29, 2023, 10:02:55 AM
Did you check the cars history for write off insurance issues eg vehicle check etc?

Yes no insurance write off
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Marco1979 on October 30, 2023, 05:27:14 AM: So before the 12v battery was drained completely the car drove normally. After the drain it does not recognize IMA. Might that be due to a complete reset in which the versions / part numbers are checked (and do not match the original setup)? Maybe the software needs to be made aware of a new engine?
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Lord Voltermore on October 30, 2023, 07:18:54 AM: I'm reminded of the joke " How many computer programmers does it take to change a light bulb? Cant be done. Its a hardware problem".

My very basic understanding is when you power up the car it does a series of computer systems checks, which only takes milliseconds.If f these checks are correct the car throws a heavy duty switch to connect the HV battery to the car. If the software checks fail the HV battery remains isolated from the car circuits and presumably shows nil bars. . Also i think the HV battery will be isolated from the car as a safety precaution in the event of a trauma such as a crash, and possibly certain electrical work being carried out. Such as replacing an engine ,batteries etc. Its quite possible the HV battery is fine, just isolated. But i dont know. Even the Honda technicians dont yet seem to know from experience without £1500 of checks. (Not that long in the workshop I suppose at main dealer rates)

I'd start with the basics. When the powertrain/IMA was removed and replaced outside the Honda network was all the wiring replaced correctly with sound electrical contacts. Or the 12v and HV battery changes. If you are very lucky correcting a loose connection this might solve all the gremlins. But I suspect there will also be some sort of software reset required. If you are very unlucky you might get electrocuted, or brickingfry some might brick the car, or get electrocuted.

Such problems will become more frequent when warranties have expired, rather than just those refused due to unauthorised work. Hopefully by then there will be more experienced HV /EV mechanics working independently at more realistic rates. Learning those skills could be lucrative. Or get you electrocuted, or brick expensive electronics, or start a fire.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: alchemistjazz on October 30, 2023, 10:15:43 AM: Quote from: Marco1979 on October 30, 2023, 05:27:14 AM
So before the 12v battery was drained completely the car drove normally. After the drain it does not recognize IMA. Might that be due to a complete reset in which the versions / part numbers are checked (and do not match the original setup)? Maybe the software needs to be made aware of a new engine?

Will take another look in the HDS if I can see any options related to the engine change.
With the new HV battery it showed 7 bars which discharged in minutes so I assume the IMA fault existed and is shorting somewhere, hence I can not access the IMA menu.

Just need to work out the fuses it could be before checking the engine grounds.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: alchemistjazz on October 30, 2023, 10:16:45 AM: Quote from: alchemistjazz on October 30, 2023, 10:15:43 AM
Quote from: Marco1979 on October 30, 2023, 05:27:14 AM
So before the 12v battery was drained completely the car drove normally. After the drain it does not recognize IMA. Might that be due to a complete reset in which the versions / part numbers are checked (and do not match the original setup)? Maybe the software needs to be made aware of a new engine?

Will take another look in the HDS if I can see any options related to the engine change.
With the new HV battery it showed 7 bars which discharged in minutes so I assume the IMA fault existed and is shorting somewhere, hence I can not access the IMA menu.

Just need to work out the fuses it could be before checking the engine grounds.

Or am I getting the IMA no communication error because the HV battery has discharged too much?
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Lincolnshire Rambler on October 30, 2023, 06:43:30 PM: I agree with LVs comments - assuming all the electrical connections have been correctly assembled you can see it’s a software bit of programming needed . Given some parts like LED light units need the correct coding for the Canbus system to reconfigure to operate the new part then it’s going to be the same for an engine swap - all the engine sensors may need to be reset to be accepted into the donor car ? Hence the Honda dealers £1500 quote to sort things out? You can imagine the complexity of controlling the petrol engine from the PCM unit . I think a real underestimate of the task involved in resolving maybe ?
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: alchemistjazz on October 31, 2023, 10:00:17 PM: Would the car have started if the new engine needs to be re-coded/re-learn? though only the electric started.
Title: Re: High Voltage Battery Charge Too Low - Vehicle Cannot Start
Post by: Lincolnshire Rambler on November 01, 2023, 11:34:13 AM: I don’t see that the cars electronics would be self contained enough to allow an engine swap out or any work on the HV battery . I can imagine the car would need plugging into Hondas diagnostics to enable a “step through “procedure to be run . This would ensure everything is checked and then allows the systems to work and hence the car to fully function . As others have mentioned the HV battery is fully isolated until the HV circuits have been checked prior to allowing its use to start the car or power up.