Problem car

[bwilson4web]

From Volume 1 of the Toyota Maintenance manual:

P3120 - HV Transaxle Malfunction (with these subcodes)

• 234 - small reduction of motor magnetism (MG2)
• 235 - large reduction of motor magnetism
• 236 - small reduction of generator magnetism (MG1)
• 237 - large reduction of generator magnetism
• (HV transaxle or System main relay)
• 239 - shaft damaged (check crankshaft position sensor)
• 240 - generator locked
• 241 - torque limiter sliding
• 242 - planetary gear locked
• (HV transaxle)
• 243 - motor resolver inter-phase short
• 245 - open or short in motor resolver circuit
• (HV transaxle or Wire harness)
• 244 - motor resolver inter-phase short (when there is a history that the state or malfunction continued during inverter fail safe mode)
• 246 - open or short in motor resolver circuit (when there is a history that the state or malfunction continued during inverter fail safe mode)
• (HV transaxle or Wire harness)
• 247 - GND short in motor temperature sensor
• 249 - Open or +B short in motor temperature sensor
• (HV transaxle or Wire harness)
• 248 - Motor temperature sensor malfunction
• 250 - Motor temperature sensor performance problem
• (HV transaxle)
• 253 - Generator resolver inter-phase short
• 255 - Open or short in generator resolver circuit
• (HV transaxle or wire harness)
• 254 - Generator resolver inter-phase short (when there is a history that the state of malfunction continued during inverter fail safe mode)
• 256 - Open or short in generator resolver circuit (when there is a history ...)
• (HV transaxle or Wire harness)
• 257 - GND short in generator temperature sensor
• 259 - Open or +B short in generator temperature sensor
• (HV transaxle or Wire harness)
• 258 - Generator temperature sensor malfunction
• 260 - Generator temperature sensor performance problem
• (HV transaxle generator)

That is what Vol. 1 of the 2003 Prius repair manual has to say. However, it also references two other codes, P3100 and P3125, but those are in another section.

Can you read out the sub-codes? They can point you to a specific area and/or connector and pins.

Do you live in an area with a fair population of rodents? They seem to like chewing on wires.

Bob Wilson

[orange4boy]

Thanks Bob, I will be able to use those on mine before I get my manuals. I suspect the worst though because of the report of shuddering before it went.

[tomfreed]

Originally Posted by orange4boy

It sounds like you are frustrated but please keep your posts clear and on topic. It is hard to wade through information on all your cars without getting confused. Please stick to one at a time.

P3120 is an HV transaxle failure code.

It can't be! The tranny had been replaced 3 times already????

Yes I am more than frustrated! I keep it simple and short. I have a code P3120 on the 01 Prius.

[tomfreed]

Originally Posted by bwilson4web

From Volume 1 of the Toyota Maintenance manual:

P3120 - HV Transaxle Malfunction (with these subcodes)

• 234 - small reduction of motor magnetism (MG2)
• 235 - large reduction of motor magnetism
• 236 - small reduction of generator magnetism (MG1)
• 237 - large reduction of generator magnetism
• (HV transaxle or System main relay)
• 239 - shaft damaged (check crankshaft position sensor)
• 240 - generator locked
• 241 - torque limiter sliding
• 242 - planetary gear locked
• (HV transaxle)
• 243 - motor resolver inter-phase short
• 245 - open or short in motor resolver circuit
• (HV transaxle or Wire harness)
• 244 - motor resolver inter-phase short (when there is a history that the state or malfunction continued during inverter fail safe mode)
• 246 - open or short in motor resolver circuit (when there is a history that the state or malfunction continued during inverter fail safe mode)
• (HV transaxle or Wire harness)
• 247 - GND short in motor temperature sensor
• 249 - Open or +B short in motor temperature sensor
• (HV transaxle or Wire harness)
• 248 - Motor temperature sensor malfunction
• 250 - Motor temperature sensor performance problem
• (HV transaxle)
• 253 - Generator resolver inter-phase short
• 255 - Open or short in generator resolver circuit
• (HV transaxle or wire harness)
• 254 - Generator resolver inter-phase short (when there is a history that the state of malfunction continued during inverter fail safe mode)
• 256 - Open or short in generator resolver circuit (when there is a history ...)
• (HV transaxle or Wire harness)
• 257 - GND short in generator temperature sensor
• 259 - Open or +B short in generator temperature sensor
• (HV transaxle or Wire harness)
• 258 - Generator temperature sensor malfunction
• 260 - Generator temperature sensor performance problem
• (HV transaxle generator)

That is what Vol. 1 of the 2003 Prius repair manual has to say. However, it also references two other codes, P3100 and P3125, but those are in another section.

Can you read out the sub-codes? They can point you to a specific area and/or connector and pins.

Do you live in an area with a fair population of rodents? They seem to like chewing on wires.

Bob Wilson

Thank you Bob for your info. No i don't have any rats in my garage to eat up the wire. This is what i remember. Last year when i was working removing the tranny i had forgotten the sensor wires to the MG2 attached so as when i couldn't remove it i found out the connector had been stretched quite a bit at the MG2 section. This is the third tranny. it could not have been three in a row. I am not sure the Autoenginuity i have can scan subcode but i think i need to chase wire point by point between the MG2 sensor and the ECU. Can you provide the diagram point to point for that? I am going to ohm it out one by one and flex the wires to see if i have a break somewhere.

One code left please God and Prius forum help me to alleviate my pain to get this headache Prius fixes

[tomfreed]

Originally Posted by orange4boy

It sounds like you are frustrated but please keep your posts clear and on topic. It is hard to wade through information on all your cars without getting confused. Please stick to one at a time.

P3120 is an HV transaxle failure code.

Trust me I am beyond frustration with the 01 and 03 Prius at this point. See the attachments those transmissions i ended up with on the side of my house. I can't recollect which one is which but one of it came from the 01 and various return exchange and other Prius year i had I ended up with that collection. After these two fix there will be no more first gen. model for me and unfortunately that is since i became fairly an expert at it.

[Patrick Wong]

Originally Posted by tomfreed

... See the attachments those transmissions i ended up with on the side of my house...After these two fix there will be no more first gen. model for me and unfortunately that is since i became fairly an expert at it.

OMG, what a picture! I think you should use a couple of those dead transaxles to hold up a glass coffee table...

You must have yet another story associated with that rusty front disc rotor and the front suspension.

Its interesting that you felt refilling the inverter coolant loop was the hardest part of the job. I have experience replacing the coolant and would have characterized physically removing and replacing the transaxle as 40x harder...

And you did this complete job 3x...

techinfo.toyota.com has complete repair manual info including the electrical wiring diagrams. I think you are on the right track, looking for bad wiring. Good luck.

[tomfreed]

Originally Posted by Patrick Wong

OMG, what a picture! I think you should use a couple of those dead transaxles to hold up a glass coffee table...

You must have yet another story associated with that rusty front disc rotor and the front suspension.

Its interesting that you felt refilling the inverter coolant loop was the hardest part of the job. I have experience replacing the coolant and would have characterized physically removing and replacing the transaxle as 40x harder...

And you did this complete job 3x...

techinfo.toyota.com has complete repair manual info including the electrical wiring diagrams. I think you are on the right track, looking for bad wiring. Good luck.

Those trannies weight a ton! They are heavyyyyyyy! 3x means 6 times in and out on the same car. LKQ kept sending me bad tranny but after the first one i paid extra for labor warranty so i got some money back. That helped! Actually the tranny was not too bad once i got a hang of it just a lot of labor removing various parts. The air bleeding is tedious and time consuming but i never said it was easier than the tranny work. What said was the Toyota procedure was hardas hell so i came up with way for half a time. Worked on 3 Preius before so i knew i got it right as as beeding the air goes.

I got the wiring print out from Toyota dealer where i took the car there twice to have it scanned. Just now i recheck the wiring and it is definitely okay. I am suspecting the ECM. Read my post to Bob Wilson as i describe in detail of what i found today.

Oh i know i am on the right track all right as there is nothing else. I had replaced and cleared all codes for battery pack, inverter, now it is still the transaxle left but i have the P3120 with ECM module not the transaxle itself on my scanner. It is time to ask Bob further. If you think about it that is very much it for the hybrid portion of this car battery pack, inverter, transaxle, ECM. These are the main 4 main modules of the Prius I bet it also applies to the 2nd and 3rd gen. with some minor change.

Yep you were right i have a story to the rusty disc and bearing axle. Those came from the 98 Mercedes Benz E300 Turbo Diesel i bought and had it shipped from the East coast to California. Long story short i had a dealer that lied to me and sold it to me online. I ended up spendng 6 months fixing that car with the rear axle noise and 50% electrical problem not working. Yep i work on diesel too Mercedes and VW TDI'S. I bought and sold many VW Jetta, Beetle, Golf TDI'S and only a couple Mercedes diesel when i still was a dealer this year. I just folded up the business this month as i plan to move out of Ca by the end of this year 2009.

Get to go to ask Bob about the Prius. Do you have any expertise you can help me with this 01? I still have the 03 Prius with even more codes than this one. One at a time at this point!

[tomfreed]

Originally Posted by bwilson4web

From Volume 1 of the Toyota Maintenance manual:

P3120 - HV Transaxle Malfunction (with these subcodes)

• 234 - small reduction of motor magnetism (MG2)
• 235 - large reduction of motor magnetism
• 236 - small reduction of generator magnetism (MG1)
• 237 - large reduction of generator magnetism
• (HV transaxle or System main relay)
• 239 - shaft damaged (check crankshaft position sensor)
• 240 - generator locked
• 241 - torque limiter sliding
• 242 - planetary gear locked
• (HV transaxle)
• 243 - motor resolver inter-phase short
• 245 - open or short in motor resolver circuit
• (HV transaxle or Wire harness)
• 244 - motor resolver inter-phase short (when there is a history that the state or malfunction continued during inverter fail safe mode)
• 246 - open or short in motor resolver circuit (when there is a history that the state or malfunction continued during inverter fail safe mode)
• (HV transaxle or Wire harness)
• 247 - GND short in motor temperature sensor
• 249 - Open or +B short in motor temperature sensor
• (HV transaxle or Wire harness)
• 248 - Motor temperature sensor malfunction
• 250 - Motor temperature sensor performance problem
• (HV transaxle)
• 253 - Generator resolver inter-phase short
• 255 - Open or short in generator resolver circuit
• (HV transaxle or wire harness)
• 254 - Generator resolver inter-phase short (when there is a history that the state of malfunction continued during inverter fail safe mode)
• 256 - Open or short in generator resolver circuit (when there is a history ...)
• (HV transaxle or Wire harness)
• 257 - GND short in generator temperature sensor
• 259 - Open or +B short in generator temperature sensor
• (HV transaxle or Wire harness)
• 258 - Generator temperature sensor malfunction
• 260 - Generator temperature sensor performance problem
• (HV transaxle generator)

That is what Vol. 1 of the 2003 Prius repair manual has to say. However, it also references two other codes, P3100 and P3125, but those are in another section.

Can you read out the sub-codes? They can point you to a specific area and/or connector and pins.

Do you live in an area with a fair population of rodents? They seem to like chewing on wires.

Bob Wilson

Bob,

I went to check the wiring on the sensor today between the MG2 and the ECM. Wiring checked out okay with the the one that has 2 wires red/white and gray on it. I have noticed this pattern.

Upon clearing the code and restart the car it ran fine with no code for about 5 minutes. After that code P3120 popped back on. My scanner keeps showing P3120 with ECM module showing when i click on the + on the scanner. I repeated the whole procedure and still same code. I had replaced everything else on this car except this thing. Is it safe to presume it is the ECM to be replaced? See attachment for the different ECM that i have. I notate on there so you know which one does what.

I am tempting to swap with the 03 that i have but hold off until i have more info. I got a feeling it will do the same thing lit up the console but will not start the engine! That 03 Prius has problem with multiple codes at this point. I am trying to concentrate getting the 01 fixes first.

What do you think before i order the correct ECM for this model year? More money spending on this car but I am very close to fixing it. I want to finish it.

By the way this it not related to this issue but I finally took heart to take apart completely the battery pack of this car i replaced last year. I was irritating to see it sitting in my garage with the car still unrepair. See pictures. I had 3 weak cells and found a way to charge individual cell with radio control car battery charger. A bit too late had i known this info. last year i could had gone ahead and did this way instead of spending $1000 for a used battery pack. I am selling good individual cell and can show anyone how to take them apart and fix or replace bad subpack battery instead of the whole thing. Anyone interested let me know. Will save some big bucks if you have a battery pack for sure.

[bwilson4web]

Originally Posted by tomfreed

I went to check the wiring on the sensor today between the MG2 and the ECM. Wiring checked out okay with the the one that has 2 wires red/white and gray on it. I have noticed this pattern.

. . . Last year when i was working removing the tranny i had forgotten the sensor wires to the MG2 attached so as when i couldn't remove it i found out the connector had been stretched quite a bit at the MG2 section. . . .

OWCH!!! ... But this isn't too bad. It is the temperature probe sensor.

From pp. DI-263 for MG2:

• Transaxle, M4, pin 3 - MMTG R-W - H10, pin 9 HV ECU
• Transaxle, M4, pin 1 - MMT GR - H10, pin 2 HV ECU

From pp. DI-269 for MG1:

• Transaxle, M2, pin 4 - GMT B-R - H10, pin 1 HV ECU
• Transaxle, M2, pin 9 - GMTG G-W - H10, pin 8 HV ECU

As a quick hack, put a 1k ohm resistor on the HV ECU pins in question. This would spoof the thermistor resistance and that should let it run ... although not an optimal solution. Just keep your speeds under 70 mph in hot weather until you can get around to running a new pair of wires. Better still, run some ethernet cable that will provide 4-pairs. Use one pair for this function and you'll have 3-pairs available for future experiments. <grins>


Bob Wilson

[hobbit]

Three "bad" transaxles would start hinting at me that the problem
is nowhere near the transaxle. Have you taken a megger to all
of your dead soldiers there, to check for winding problems?
Have you looked at the resolver signals coming back at the ECU
leads to make sure they're solid? When you replace one of these
guys [and your efforts wrangling those heavy suckers are quite
impressive, btw] it's very easy to damage the plastic connectors
carrying the resolver and temp sensor wiring -- they're sensitive
low-voltage things, they need to have NO flakiness back to the
ECU. I don't know if your Autoenginuity can give you those
info-codes correctly -- what version do you have, and have you
asked their support folks about how specific they're able to
get on the 01 - 03 Prius? This is one of the grey areas of
aftermarket scantools, those bloody-annoying info-codes.
.
But it sounds like it's time for a good point-diagnosis rather
than trying to parts-swap your way out of the problem...
.
_H*