New codes for old 2003 still won't start.

I recently pointed out that while the Autoenginuity software may be able to connect, the data it displays cannot always be trusted. Louder voices countered that the software works just fine.

Welcome to reality. I'm sorry that you had to find out the hard way.

Don't worry about the CCS right now. You need information from the HV ECU and the HV battery ECU.

Nor would I. Your experience may ruffle a few feathers on this forum. If anyone squawks, ignore them.

Ask Autoenginuity if there is a known problem connecting with the Gen 1 HV battery ECU.

Also, ask them if the software can access:

- data (not just codes) from these two ECUs

- information codes (not OBD-II codes)

- freeze frame (hybrid data, not generic data)

If anyone on this forum gives you flak for taking an interest in freeze frames, ignore them, as well.

After all, you just want to get your car started.

 

Good deal. Roughly what did it run?

The reason I ask is the Graham mini-scanner does not read everything I'd like to see. But I'm not thrilled with having a laptop in the car unless I can use it as a total data recording system. It really comes down to the degree I might use it for custom polling of key system data without distracting the driver.

CCS - Cruise Control Switch (?) ... the electrical diagram shows two ground wires to the HV ECU on pins 31, 24 of connector H14. The cruise control switch input goes to pin 16 labeled "CCS". I'll try to post details of how to ohm-out the circuits tomorrow. However, this web page will give you a guide to where the signals are located.

HV Battery No response - sounds like the CAN bus connector to the traction battery is loose or disconnected. Alternatively, the HV ECU might be kaput?

HV ECU P0012 - can't find it but if the engine isn't running, it may make sense. I'll have to look at it closer tomorrow.

EMPS C1571, and C1572 - speed sensor malfunction, the ambiguity group:

• right or left rear speed sensors
• sensor installation
• speed sensor rotor
• speed sensor circuit
• Brake ECU
• Electronic Motor Power Steering (EMPS) ECU

Let me know if this helps.

Bob Wilson

 

This sounds like communication problems, but there's no CAN
bus in the gen1 -- just pairs of hardwired lines between the
various pieces. Look up stuff like BTH+ and BTH- for how the
battery ECU transmits its status. I probably missed the whole
leadup to this; was the car damaged at some point and needed
harness repair?
.
_H*

 

A salvage, the thread started here:

http://priuschat.com/forums/generation-1-prius-discussion/76677-gen-1-p3100-p3125-2.html#post1068468

BTW, I noticed a set of 2002 manuals on Ebay: 200449182450

Bob Wilson

 

I would point out that one time I accidently left the HV Battery ECU unplugged and the car started just fine, but it did throw a code that it couldn't communicate with the Battery ECU.

 

A good point, and a possibility. However, given the other communication problems, and the fact that Autoenginuity has acknowledged issues with their software when connecting to the Gen 1, a quick call to AE may save the person a lot of time. AE will probably already know where the communcation problems are.

 

You had said in the previous thread that the vehicle has been sitting for two years. Look at the battery voltage and state of charge with the key to the ON position (not READY).

What are they?

 

Ignore the dash display. Use your scan tool.

 

That is luck indeed, and good news for you. Now you can communicate with the modules.

The P0012 out of the HV ECU was a garbage code generated by the Autoenginuity scan tool. The HV ECU doesn't output that code. Heck, the Prius doesn't output that code.

You should be able to find a reading for overall pack voltage. At any rate, it looks to be about 240 volts.

Your HV battery voltage is too low. After connecting the battery and reading that voltage, the system shuts down. It appears that you need a new battery pack, unfortunately.

Sorry to be the bearer of bad news. Two years is a long time for a Gen I battery pack to sit.

You can ignore that code. It's a by-product of the battery issue. There is no code directly associated with the problem you are having. The system simply shuts down.

What is the release number for the updated AE software?

 

The manual doesn't offer much help on "C1259/59 Malfunction in HV ECU". It is probably a good idea to double check fuses and 12 VDC battery level. We've seen a lot of indistinct, random errors that disappeared after a marginal 12 VDC battery was replaced. The traction battery module pair voltages are pretty low.

A normal NiMH cell is 1.2 volts (see Wiki or NiMH datasheets) and there are six cells per module, nominal 7.2 volts. Two modules should normally run 14.4 V. Could you list the voltages by module pairs?

Here are some historical data on traction battery voltages:

Also:

And:


Some folks in "Prius Technical Stuff" have rigged up bulk chargers for the traction battery. The problem is if any of the modules start showing a 1.2 VDC difference, that is the signature that one of the six cells has internally shorted or bad. For example, I bought a replaced, traction battery pack a couple of years ago. Of the 38 modules, two were marked as "NG" (no good.) So I started testing with a computer controlled, charger and found one hard-failed module:

This is a hard failed module. But before the module fails hard, they can get pretty weak:

You'll notice the charge/discharge cycles on the left are pretty flat. But this lower Ahr capacity means the variation between modules tends to increase as they age and the car will throw a code if the dV is too much.

There is a traction battery test that involves a controlled discharge and charge that requires all module pairs be within 0.3 V. In theory, bulk charging all modules may bring them up close enough. Still bulk recharging has to be done carefully:

NiMH batteries prefer a constant current charger and careful monitoring to avoid over charging. . . . What have you got to lose ... a bad traction battery?

In my case, I've got a MRC 989, RC hobby charger that can cycle charge/discharge to recondition modules:

My plan, should I rebuild a traction battery pack, is to measure the Ahr capacity of each module and make sure I have a pack of balanced modules. Then I'll bring all of the modules to an identical SOC, more about this if you decide to go this way. Balancing the battery modules matches the best practices for large series batteries.

Another option is to contact "Re-InVolt", look for a salvage battery, or buy a new one from Toyota. Some folks have had luck rebuilding the NHW11 traction battery using NHW20 modules but you'd need two packs to get the 38 modules needed.

Bob Wilson

 

See my post, above. Also re-read the service definitions of C1259. You are missing some relevant data.

Neither fuse issues nor 12V battery levels will trigger a C1259.

Why do you think they will? Please be as specific as possible.

No. A charged module typically runs above 14.4V, just as a "12V" battery typically runs 12.6V or so when fully charged. The key is to understand the use of the term "nominal".

A 1.2V difference does not indicate a short. However, if the modules are showing as much as 0.75V difference at rest, it is very likely that they will show more than a 1.2V difference fairly quickly under load.

Eyes, fingers, things like that.

 

LOL! See my updated post below.

If you have a Prius problem, trot it out and we'll help you figure it out.

Bob Wilson

 

I looked it over; sorry, but the original errors remain.

I don't, thanks.

 

Excellent. When you get one, either a Prius or Prius problem, let us know. In the meanwhile, some of us have 'hands on time' and are quite happy to address Prius problems. I prefer to trust my "lying eyes."

Bob Wilson

 

If you decide to try and salvage the traction battery, do put it on a bench and let us know. Alternatively, you might join the Yahoo Group, "Prius Technical Stuff," a technical group that includes members who have done similar work in the past. In the meanwhile, you might scan the message archives that go back to 2000 and associated photos and data reports.

Bob Wilson