Gen 1 HV BATTERY REBUILD WITH 2G CELLS

My diagnosis: very talented Prius technician, with an inferiority complex.

 

If I understand his posting correctly:

• vehicle starts, goes into READY, engine runs and charges - MG1 sounds good, engine sounds good,
• vehicle runs forward without errors - MG1/MG2 sound OK and the parking paw disconnected. Normally a fraction of the power, ~28%, should take the MG2 path. We can't really tell but if there are no errors raised so it sounds OK.
• vehicle fails when shifted into "reverse" - so what is different? MG2 signals and power are the same, just different timing. There is no internal mechanical gear. The HV ECU handles the timing in response to the operator control. I'm not ruling out another failure mechanism but it sounds like this is the first time "R" setting is being attempted with the shifter.

Bob Wilson

 

Owch! It has been a long, long time since I can remember feeling "inferior" . . . although some forms of pornography come close.

In all seriousness, folks here make a name by showing what they've got. Tearing down others, who has time? Who cares? It hurts the reputation of the critic, especially when they don't bring anything else to the game.

The trick is to ask folks to 'demonstrate' their talent, bring on their "A game" and show what they know or can figure out and don't sweat the small stuff.

Bob Wilson

 

If you think folks have an inferiority complex when they make a sincere effort to help someone with a broken car get it running as quickly and cheaply as possible, and make that effort anonymously, then please, sign me up twice.

 

That's what I understand, as well.

Yes, but there are errors, and codes to define them.

In reverse, there is no engine torque to propel the vehicle.

A well-written fail safe strategy will protect the driver and the vehicle first, and try to get the driver home as a second priority. And that's what is happening here. Since engine torque is available, it can be used to propel the vehicle forward after the HV ECU "sees" that for some reason it shouldn't use MG2. In reverse, however, it briefly applies torque, and then some fail-safe threshold is triggered. However, we don't know if it's MG2, the inverter, the battery, or something else at fault.

You are trying to diagnose the vehicle from its behavior. However, the "behavior" of a Gen 1 Prius with codes is often no more than a fail-safe mode that has been triggered by the root cause of the problem, to protect the vehicle and its occupants.

If a shift selector circuit problem was the issue, I'd expect the vehicle to not go into reverse at all, and to set a code. At this stage, all indications point in another direction.

 

^^ Thanks for the informative post without the attitude. *So* much easier to digest and learn from.

 

You haven't been paying attention. There is ample reason for, as you say, "attitude".

While forum member bwilson4web posts regularly on this forum, many of his posts are, unfortunately, riddled with errors. This is not, of course, a cardinal sin; we are all here to learn and to try to help.

Unfortunately, he often throws quite the fit when anyone posts technical information that contradicts his theories, and works to discredit or drown out such information, even if such efforts could inhibit the successful diagnosis of a broken car. When that hasn't worked, he has resorted to name-calling and other personal attacks. In that sense, he is unique among all forum members. To be blunt, he is a very angry man. You can see it for yourself in this thread; after I had pointed out errors in his posts and made an effort to put the diagnosis back on track, he responded

Not much to laugh about, really. Indeed, it is not difficult to find threads in which folks have spent weeks trying to diagnose their vehicles based on his theories, eventually giving up and wandering away. I don't think that's funny, and I hope you don't, either.

To be frank, the advice that bwilson4web gives is often so far off the mark that the most helpful thing one can do is try to steer the OP away from the largest howlers. There is simply not enough time to fix it all. So when I read responses such as

I am well aware that it is BS, rather than a genuine sentiment. You, unfortunately, were not, and that's why Mr. Wilson has played you like a piano. In all sincerity, I wish you better luck next time.

 

Thanks for the concern. Let me tell you, it has been agony on my poor toes.

Now, BACK TO TOPIC.

 

With all due respect, you initiated the diversion. What do you think is wrong with the OP's vehicle?

 

When you rebuilt your HV battery, did you disconnect the 12V battery?

 

Great, then you'll only be seeing current codes if you are able to access them.

You would be able to skip that step without a problem when swapping a Gen 1 battery ECU.

For the codes you are reporting, no.

 

Ok, let's get back to work. I've turned up the squelch.

FUSES

It took these rather grainy photos Friday morning of the two engine compartment fuse boxes:








The empty slots appear to be places for spares. I do have a few spare fuses in the boxes. Otherwise the fuses and relays look ordinary.

I'll start a follow-up post with hopefully the current symptoms.

Bob Wilson

 

BACKGROUND

• P3100 - HV ECU malfunction
  • Check and reseat connectors - again there are a long list of subcodes but without a Techstream, they are not otherwise available.
• P3125 - Converter & Inverter Assembly Malfunction
  • Huge list of subcodes, pp DI-271-306 this is where the Toyota Techstream provides a roadmap. This is where getting the codes from a Toyota service center pays off. Start with checking the connectors.
• ABS light - this controller will flash the error codes if you use the OBD connector jumper technique described in "AE Pig-tail and code flasher"
• vehicle starts, goes into READY, engine runs and charges - MG1 sounds good, engine sounds good,
• vehicle runs forward without errors - MG1/MG2 sound OK and the parking paw disconnected. Normally a fraction of the power, ~28%, should take the MG2 path. We can't really tell but if there are no errors raised, it sounds OK.
• vehicle fails when shifted into "reverse" - so what is different? MG2 signals and power are the same, just different timing. There is no internal mechanical gear. The HV ECU handles the timing in response to the operator control. I'm not ruling out another failure mechanism but it sounds like this is the first time "R" setting is being attempted with the shifter.

The HV ECU operates the inverter. So it makes sense to look at the inverter HV ECU signals first and those associated with "reverse." Let's look at a list of all HV ECU signals and see which ones we can rule out and those of interest.



The H10 connector connects to the motor generators, MG1 and MG2. Since MG1 appears to be OK but MG2 fails on reverse, lets keep these as 'signals of interest:'

	Column 1	Column 2	Column 3
0	signal	line	color
1	msng	20	green
2	msn	13	red
3	mcs	14	pink
4	mcsg	21	blue
5	mrf	19	black
6	mrfg	18	white
7	mmtg	9	red-white
8	mmt	2	gray

These are likely sensor from MG2, possibly the resolver.

Now H11 carries the signals between the inverter and HV ECU:

	Column 1	Column 2	Column 3
0	signal	line	color
1	msiv	21	green
2	msdn	13	yellow
3	mit	11	blue
4	mwu	6	green
5	muu	4	red
6	mvu	5	white
7	mivg	26	black
8	miva	16	black
9	mivb	7	white
10	miwb	17	green
11	vb	20	yellow
12	miwa	25	red
13	giva	19	black
14	givb	8	white
15	giwb	18	green
16	giwa	28	red
17	gsdn	12	yellow
18	git	23	blue
19	gwu	3	green
20	gvu	2	white
21	guu	1	red
22	givg	1	black
23	mpiv	14	black
24	gsiv	15	green
25	gpiv	24	black

These are the signals common to both codes.

Now the last signal of interest are the shifter on H13:

	Column 1	Column 2	Column 3
0	signal	pin	color
1	R(everse)	14	Red-Blue
2	vsft	12	white
3	sft	11	black
4	gsft	21	red

Of interest because reverse is associated with the latest error.

So now comes the challenge, working off the list. Where would you like to start?

Bob Wilson

 

Reseating the connectors seldom works but it is relatively 'cheap' and yet works often enough. Sounds like they are in good shape. Also, thanks about the HV ECU location. This suggests the engine and power steering ECUs may also be located behind the glove box.

Did you remove the coolant lines? The reason is replacing the coolant is tricky to get the air bleed out of the lines. In my case, I've taken the inverter 'out' without opening the coolant lines. I have replaced my coolant before including bleeding the lines.

Let's see if we can keep it rolling a little longer. <grins>

There is a UK member of the "Prius Technical Stuff" group, Clive, who has an NHW11 and others who have posted from time to time. There is also an European Prius group whose activity varies. If you introduce yourself, maybe one of them might volunteer to come 'take a look' at her.

Tell me more about the 'inspection' deadline ... the end of this month. What is the risk if the car is not through inspection by the end of the month?

The reason I ask is it has been dreadfully hot, 35-38 C with a lot of humidity. I've been taking the dogs out for their walks before sunrise and it is still equitorial.

Bob Wilson