03 still won't start. Only DTC 1259

Page 392 is for your DTC. It may also be possible that the diagnoistic equipment your using is not going deep enought into the ecu to pick up other DTC'S. I have came across that before.

 

Ok Dirk, well that delta is slightly over 2V (hi block =15.39 and low block =13.25) I think the HV ecu would not try to start the ice with that much delta. I'm still trying to understand for myself how much delta between hi and lo blk would cause a problem, someone said somewhere it's 1.5v max delta, but I cannot find that post. Anyway I really think that 2.14V delta is too much. Try charging just those 13'ers to bring them up to around 15, or close to the others, and then try to start. If that's what it is you will hear the engine start but I wouldn't run it very long with that much of an imbalance in the pack. Keep a keen eye out for any overheating of the cells in question since once it does start it will immediately be charging the pack.

 

I plotted the values and it looks like these in particular may have problems:

13.25
13.49
14.12
14.13

Based upon the voltage drop, it is likely that one of the two modules has a bad cell. Charging these up may buy time.

Bob Wilson

 

Actually, you don't need to plot them. Just look for the lowest values.

A module can have a normal voltage reading and still have a bad cell.

 

What are the module voltages, by comparison, after you try to start the vehicle?

 

The nominal voltage for a NiMH cell is 1.2V, each module has 6 cells for 7.2V, so the nominal voltage for a block (two modules) should be 14.4V. If it's less than that you have at least one shorted cell.

The nominal voltage is actually the uncharged voltage. Charged cells should be way above this. I've seen the NHW20 battery (28 modules, 168 cells, nominal 201.6V) quoted as 226-232.5V when showing six out of eight bars, so if each block were charged equally this would be 16.14 - 16.61V per block.

 

Now this is silly:

There are patterns easily detected by plotting data. We often find the 'knee in the curve' that has evaded your nonsense response. Plot the data and learn.

As I pointed out before, the problem modules are in these pairs:

13.25
13.49
14.12
14.13

Concentrate on the lower voltage modules of these pairs and see how well they recover.

Bob Wilson

 

As I said, a module can have normal voltages and still be degraded. The reverse can also be true. Finally, the voltages may not be accurate. It would help to compare voltages reported by the scan tool to actual voltages.

You really need to look at the battery pack as a system.

 

Still no facts and data:

The original posting: http://priuschat.com/forums/generat...l-wont-start-only-dtc-1259-a.html#post1133327

We have a list of traction battery voltages and the facts remain, four voltages are distinctly out of the normal distribution. Those modules need to be looked at first.

Bob Wilson

 

No. You need to first verify the voltages, for two reasons:

1. The Autoenginuity is buggy, and often returns false values. If you're lucky, they will be obvious values at the limit of measurement (-128, or something like that). If you're not, it will lead you down a dark path. So you need to confirm values with direct measurements.

2. When a Gen 1 HV battery has been sitting for a while, it is possible for a thin layer of corrosion to develop between the voltage sensing wires and the terminal itself. So you need to confirm that there is no significant voltage drop between each sense wire and the appropriate terminal.

if you are satisfied that the reported data is correct, you can then try to start the vehicle, which will put a small load on the battery, and watch your voltages. Ideally, you would use your Autoenginuity to take a snapshot of the process. What are the voltages after you try to start the car, and how do they compare with your "at-rest" voltages?

Keep in mind that - based on the information you have supplied - your HV battery was diagnosed as faulty quite a while back, prior to the recharge experiment. The new numbers may help you make sense of that diagnosis.

 

It still shows up as "Malfunction in HV ECU":

• Voltage of terminal IG2 in brake ECU is 10.5 V or more continues for 1.5 sec.
• Regenerative malfunction on HV ECU side
• Received data is accepted as valid

"Check the DTC for the HV control system."

It then points to DI-182 and goes on and on.

Can you pull a code from the HV ECU?

Bob Wilson

 

by jk450:
"Ideally, you would use your Autoenginuity to take a snapshot of the process. What are the voltages after you try to start the car, and how do they compare with your "at-rest" voltages?" The at rest voltages are easily and accurately had, however after a startup the system immediately goes into charge mode so you will see nothing but charge voltage compared to ambient. I have captured the start voltage sag w/AE and it must be done in a specific sequence ie:start software w/ignition on but not ready yet, after stable, start and name the record file (example: record hi and lo block), then when it all looks stable go ahead and start the ice. The resulting voltage "sag" just before the charge cycle starts (aprox. 2 secs. after ice start) is the voltage sag from turning the ice through MG1's current draw. After this short time, it will go into "charge mode" so the voltage goes way up again, rather quickly. Just keep this in mind anyone who is trying to read startup voltage sag of their hv pack.

 

True for normally running vehicles. However, Dirk's car isn't starting. That's why I want to see the startup voltages. I want to see the voltage drops as the inverter puts a load on the battery.

 

Right, good point jk450, that is a huge difference.
Here is a plot I did a while back on our 03' where I recorded the starting voltage sag on the traction battery, then as soon as it starts the charge cycle you can see it goo right back up. Engine start was at 28S and charging cycle started at 35S. Displayed are hi and lo block voltages.

 

No. Just make sure your voltmeter leads are directly touching the module terminals themselves, when measuring module voltages. If the battery has had the factory leak repair, make sure the sealant isn't covering the end of any terminal that you are measuring.

Here is some food for thought, which may or may not be applicable to your situation:

Luscious Garage | Blog | Toyota Prius code P3030 “High Voltage Line Snappedâ€

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