Power System Problem dash warning

Faults and Technical chat for the Honda E
green1
Posts: 59
Joined: Tue Mar 26, 2024 1:18 am

Post by green1 »

EEEE wrote: Fri May 10, 2024 7:50 pm i believe nearly everything runs off the 12v system. almost certainly the coolant pumps and the valves etc. not sure on the water heater. it could be 12v but supplanted by the dc to dc converter. when the 12v goes flat, the car is locked out of itself effectively. no power to energise the systems and close the HV contactor/isolator and get the dc-dc converter up and running.

you can quite quickly drain the 12v if you are not careful, especially if your 12v is a bit lame.

interesting that the dealer mentioned its a software glitch, not one anyone else has reported. the software of course residing in the modules and controllers, and nothing to do with the infotainment and the single update for that that has been pushed out.
That is interesting, so the HV battery is purely for traction, and even the systems that are maintaining the HV battery are probably, in a sense, electrically isolated from it.

I did have sight of a service diagnosis sheet with the error code P04CA on it (different from the one that was shown on my OBD), but which apparently for Honda's also indicates something to do with coolant pump performance, and they mentioned explicitly that the pump was tested separately from the update being pushed. I suppose I could use the tech info website to check again but I don't want to pay another 10 Euros for now :D. Let's see what happens.

green1
Posts: 59
Joined: Tue Mar 26, 2024 1:18 am

Post by green1 »

EEEE wrote: Fri May 10, 2024 7:50 pm i believe nearly everything runs off the 12v system. almost certainly the coolant pumps and the valves etc. not sure on the water heater. it could be 12v but supplanted by the dc to dc converter. when the 12v goes flat, the car is locked out of itself effectively. no power to energise the systems and close the HV contactor/isolator and get the dc-dc converter up and running.

you can quite quickly drain the 12v if you are not careful, especially if your 12v is a bit lame.

interesting that the dealer mentioned its a software glitch, not one anyone else has reported. the software of course residing in the modules and controllers, and nothing to do with the infotainment and the single update for that that has been pushed out.
Put it to charge last eve at a 3 kW street charger. Warning re-appeared after a few hours when it got to about 60%, OBD shows the exact same error again. Then charged fully, the car drives the same. So nothing seems to have changed then. Looks like I have to take it back in, and either the problem wasn’t fixed or the DTC code is downstream/upstream of some other problem and is misleading 😑
green1
Posts: 59
Joined: Tue Mar 26, 2024 1:18 am

Post by green1 »

I think I'm going to disconnect/reconnect the 12V, then after that replace it with the Yuasa YBX5053, just in case this is a glitch that is being caused by the old 12V; each time the error arose, the car was being charged and the infotainment had been used for quite some time while it was being charged. I suppose it's at least somewhat possible that nothing is wrong, but that a short term drop in voltage due to a weak battery under load / crappy 12V charging logic is triggering a temporary condition that is producing the error and causing it to stick afterward.
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EEEE
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Post by EEEE »

I'd say its unlikely, if the 12v was on its way out or you had the draining issue, you'd have been locked out of the car by now. Many people have reported flat batteries, but none with the error you mention.

if you plan to keep the car, replacing the battery isn't a bad thing to do so it's not money wasted in my mind.
'21 e Advance - Charge Yellow - E1702RR alloys
'17 Civic Sport CVT
'00 Prelude 2.2VTi
green1
Posts: 59
Joined: Tue Mar 26, 2024 1:18 am

Post by green1 »

By the time the battery is likely to be delivered I'll be going back to the dealer in any case, so it'll have to wait.

I plan to keep the car, provided the dealer can repair whatever the fault seems to be then. If it happens again after I leave the car with them this time I might reject the vehicle under CRA because this should not be happening and if it does, they should be able to properly diagnose and fix it. I'm already annoyed that I have to drive it back, I asked them in no uncertain terms if they were absolutely sure the fault was fixed and that I was happy to leave it with them for a few days if there was any doubt so as to avoid another round trip.

Let's hope it's better this time around, where I am going to leave the car with them so they have more time to figure it out.
green1
Posts: 59
Joined: Tue Mar 26, 2024 1:18 am

Post by green1 »

All drives since Monday the error has gone and hasn't reappeared yet, not really sure what's going on. I think I'll leave it for a week, keep driving as normal, charge again over the weekend and see if it reoccurs, and in that time hopefully also swap out the battery, then if necessary take it back in to the workshop.
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EEEE
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Post by EEEE »

Perhaps where the car has been sitting for so long, the valves which control the coolant flow are gummed up - leading to the system noticing temps not changing with respect to the valves commanded positions - hence the need for a journey to bring about the fault. If it was a short/open circuit with the valves solenoid, I guess the error could be reported straight away (no running required).

Maybe related, having purchased a new clutch master cylinder the other day (for a different car obviously) I couldn't believe how much assembly grease was packed in the fluid inlet. Same goes for the one that was almost removed, the pipe leading from the brake reservoir to the cylinder had a massive gob of assembly grease inside it. No wonder it failed, I bet over time the grease goes hard, then gets drawn into the master cylinder and wears/damages the seal (PS, do not try to remove the master cylinder in a 2017 astra, worst job I ever started (and then gave up on)).
'21 e Advance - Charge Yellow - E1702RR alloys
'17 Civic Sport CVT
'00 Prelude 2.2VTi
green1
Posts: 59
Joined: Tue Mar 26, 2024 1:18 am

Post by green1 »

EEEE wrote: Wed May 15, 2024 7:44 am Perhaps where the car has been sitting for so long, the valves which control the coolant flow are gummed up - leading to the system noticing temps not changing with respect to the valves commanded positions - hence the need for a journey to bring about the fault. If it was a short/open circuit with the valves solenoid, I guess the error could be reported straight away (no running required).

Maybe related, having purchased a new clutch master cylinder the other day (for a different car obviously) I couldn't believe how much assembly grease was packed in the fluid inlet. Same goes for the one that was almost removed, the pipe leading from the brake reservoir to the cylinder had a massive gob of assembly grease inside it. No wonder it failed, I bet over time the grease goes hard, then gets drawn into the master cylinder and wears/damages the seal (PS, do not try to remove the master cylinder in a 2017 astra, worst job I ever started (and then gave up on)).
There were gobs of grease inside the pipe? Wow, how does that even happen.

I think your hunch makes a lot of sense.

I suppose one question is, which I don't know the answer to, under what conditions is their highest demand on the battery cooling - and maybe I can try, with some caution, to use the car under those conditions to see if it triggers earlier. I assume when temperatures are high, when the car is being DC charged and/or when it's being driven at motorway speeds (although will avoid the latter actually as manual says avoid high speeds). The DTC code suggests it's a problem with the heater rather than the cooling function, and under current conditions I doubt the battery would need to be warmed up. That said, if the valves in my car's coolant loop are for whatever reason more prone to seizing up this sort of spurious error can trigger.

So far the two conditions in which the error is being triggered are:

1. After it has been sat charging slowly for a few hours while the infotainment is on. Haven't DC charged yet, will try to do this week. Haven't tested while off, but if you're right it should be no different.

2. After the fault has been triggered while charging (not 100% sure but I don't think I have seen the warning trigger when driving after charging when it was not first triggered during the last charge, which is a bit confusing), then after the car has been off for a while, it can take anywhere from 5 - 60 minutes driving for it to show back up, and as of the last two day's drives it hasn't shown at all.
green1
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Joined: Tue Mar 26, 2024 1:18 am

Post by green1 »

Have driven the car pretty much as normal but avoiding motorways and the warning hasn't yet reappeared, drove it from 100% to 10% over the week and now put in on a street charger again. Reading the OBD I can see a "P0E12 error, Pending, Confirmed, Test not completed in current driving cycle" but this is instead marked as Archived/Inactive.

Now I'm thinking that although the error showed once again on the first charge since I got the car back, that maybe that was some data left in the ECU memory, but now it is able to clear on it own because the problem was indeed fixed? Not sure, but looks like a possibility, fingers crossed, if I drive it back down to low charge after this and it doesn't come back it's probably that? :lol:
green1
Posts: 59
Joined: Tue Mar 26, 2024 1:18 am

Post by green1 »

Charged to 100% turned the car on, got in, looked fine, put car in ready mode, after a few minutes stationary the warning comes back. Turned the car off for a few minutes, turned it on again, warning gone again. Drive back to home which takes a few minutes, warning comes back.

OBD reads test failed current drive cycle for the same error code.

Sigh, I’ll have to take it back to the workshop.
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