Problem car

[Patrick Wong]

Hi Tom,

Glad to hear that you were able to fix the 2003. What was the problem with that car?

Regarding the 2001 and hybrid vehicle ECU replacement, I do not recall that there's any programming required. The immobilizer ECU does require programming when it is replaced.

I no longer have my 2001 repair manual to consult so I suggest that you visit techinfo.toyota.com and download repair manual pages that relate to HV ECU replacement. Looks like you are very close to a successful conclusion to your repair efforts; good luck.

[bwilson4web]

Originally Posted by tomfreed

. . .
While waiting for the part i went to fix the 03 problem. I got it fixed today and i couldn't be happier. One left to go.

Congratulations! So the one remaining is the 2001?

Originally Posted by tomfreed

. . . I got the hv ecm came in today. I hooked it up and same thing that is [it rjw] won't start but dash lights all came on.

I drove to the dealer talking to the tech. that scanned this car last year. He told me there might be no communication between the ecu and the vehicle due to the mobilizer (alarm i believe). He told me to jump pin 4 and 13 OBD2 connector and turn key on and leave it there for 30 min. Car should start. No luck.

All six control controllers are tied together via the CAN bus and if it broken, a lot of things won't work.

There is a hidden diagnostic screen that requires a funny touch pattern. Search the archives and see if you can find it. This diagnostic screen also lets you see if the CAN bus is working.

Originally Posted by tomfreed

. . . Also it is confirmed the hv ecm since i was able to drive for about 5 min. without code came on. Once it came on still the same p3120 HV ECM as subcode. By the way the ecm that came in today that i bought i did have the mg1 and 2 signals when i scanned but won't start the car. The bad one does start the car but does not have the mg2 signal.

My question is this. It is at this point no doubt it is the hv ecm. My problem is all compatible hv ecm that i have xxxx60, 62, 40 gave me dash lights but won't start the car and they all have mg1 and mg2 signals when i scan. WHAT IS THE WAY TO DO TO GET THE REPLACEMENT HV ECM TO COMMUNICATE WITH THE CAR FOR IT TO START?

I've got to wander off to work but I'll go over what the book says about diagnosis of CAN bus problems later this evening.

Bob Wilson

[tomfreed]

Originally Posted by Patrick Wong

Hi Tom,

Glad to hear that you were able to fix the 2003. What was the problem with that car?

Regarding the 2001 and hybrid vehicle ECU replacement, I do not recall that there's any programming required. The immobilizer ECU does require programming when it is replaced.

I no longer have my 2001 repair manual to consult so I suggest that you visit techinfo.toyota.com and download repair manual pages that relate to HV ECU replacement. Looks like you are very close to a successful conclusion to your repair efforts; good luck.

On the 2001 that is exactly the cause IMMOBILIZER. Had i had this info. long time ago i would have fixed this 01 already. I got so frustrated after bought another ECM on Ebay and still same thing not able to start i went to dealer and spoke to the same tech. that scanned the car last year. He gave me the info. to get the hv ecm communicates with the car. This is the fix
Now that i think about it those bolts lying inside the inverter when i bought the car did many damages to this car: inverter, transaxle, hv ecm, battery pack. I also had bad luck with LKQ sold to me two bad transaxle so i ended up with doing the work 6 times in and out for the transaxle

All along the car was fixed just need to reset the HV ECM so it would disable the immobilizer. A little info. went a long way. Thank you Patrick for confirming the ECM info. I did use the XXX60 after resetting it and it did work. The car did start and i was able to see MG1 MG2 reading and no more code on scanner. I am going to return the XXX40 i bought on Ebay. Seller listed return is allowable. I still have XXXX63 i am going to sell. The original XXXXX40 was indeed bad. Thank you Bob for the info. on the MG1,2 temperature reading. To those who doubted my ability to fix the car when i was so close i proved them wrong. My tenacity and determination did pay off As a matter of fact yesterday was a quick ass day for me. I fixed both 01 and 03 in the same day. I had the 01 for 14 months already sitting in my garage monkeyed working, sweating, cussing with all those issues. I had the 03 for a few months with the intention to sell for a friend. The 03 ponked out on me just the day i listed the car for sale on Craiglist.

What fixed the 03 was putting some gas in tank (fuel indicator flashing), clean throttle body, putting another good battery in parallel with the small battery (i have a weak battery), bypass temporarily the brake fluid sensor (code on scanner).

I drove both cars for miles and no more dead triangle and engine light Now i can sell these suckers and start packing for the move to Florida. I bought a house paying cash in full last week. By the end of the year i should be out of California and stay out of Ca indefinitely. I am no longer a used car dealer and anyone thinks it is an easy and profitable business go ahead and be one. I know better after 4 years

I have few pictures for your enjoyment of my sweat and blood in the 01. Also trying to fix the Prius without info. and scanner is like walking in the dark forest with your eyes blindfold. However it is not difficult and scary at all if you have mechanic skill, a scanner and info. manual. I do not have any info. manual. I only subscribed to that useless All Data from A.Zone for the PRius and it already expired. What helped to fix was the scanner, this Prius forum, dealer tech and most importantly my belief and determination. I doubted that anyone did this many repairs than i did for the 01 for not being a full time professional mechanic.

I have not figured out closely yet but roughly by the time i sell the 01 i would have lost over $3000 I paid $5500 at dealer auction 8/08. Stupid me All those labors, times, stresses and losing money at the same time

[tomfreed]

Originally Posted by bwilson4web

Congratulations! So the one remaining is the 2001?

All six control controllers are tied together via the CAN bus and if it broken, a lot of things won't work.

There is a hidden diagnostic screen that requires a funny touch pattern. Search the archives and see if you can find it. This diagnostic screen also lets you see if the CAN bus is working.


I've got to wander off to work but I'll go over what the book says about diagnosis of CAN bus problems later this evening.

Bob Wilson

You make it too complicate Bob, no need to chase CAN bus. Here is the info. that will benefit anyone that is fixing the 01-03 Prius. I don't know about the later model since i don't have one yet. I worry about it if i ever buy Prius again.

There are 4 major components for the hybrid portion:

1. transaxle which consists of motor, generator, starter and CVT (continuous variable transmission)

2. inverter

3. battery pack

4. hv ecm

A good scanner will pinpoint with surprisingly accuracy of the problem as Toyota engineers did a very good job of having problems detect and store on board computer for later retrieval diagnostic and repair. I use Autoenginuity scanner which i paid another additional $150 last year to have the Prius hybrid option add on. It was and is a worthwhile investment. It can read battery pack voltages and multitudes of other functions for the hybrid portion. In the 01 case it was the MG1 and MG2 temperature reading i was having problem. It turned out the MG2 value was not there coming out of the ECM. Bob pointed out from previous posting and i confirmed with the scanner.

If another replacement HV ECM is put in it has to be reset so that the immobilizer would not prevent the car from starting.

To do it jump pin 4 and 13 at the OBD2 connector, turn key to on and leave it on for 30 min. Pull the jumper out then restart the car and it should start.

You have no idea how happy i was yesterday fixing two dead Prius at the same time in particular the 01 sitting in my garage for 14 months sucking over $3000 for parts and a lot of my time and stress

There you go i am done with the 01-03 Prius. Too bad just when i am getting very good fixing these cars i am not interested in them anymore

[yardman 49]

Originally Posted by tomfreed

..........There you go i am done with the 01-03 Prius. Too bad just when i am getting very good fixing these cars i am not interested in them anymore

Congratulation, Tomfreed. Great perseverance, but man, you are one crazy dude!

Remember though: perseverance alone won't get you through all situations. More information early on in the process can save you a lot of pain and grief, as you now know. I liked your comment about the "black forest".

Now that you've mastered the G1 Prius, you should try your hand at a G2. Maybe you can open your own Prius garage in Florida!

Best wishes,

[Patrick Wong]

Originally Posted by tomfreed

...There you go i am done with the 01-03 Prius. Too bad just when i am getting very good fixing these cars i am not interested in them anymore

Hi Tom,

Nice work. I agree that it doesn't make sense to fix and resell the Classic Prius (esp when the car is not running and you don't know exactly what is wrong) because the market values are so low and the potential repair costs are so high = little or no opportunity for profit.

Most of what you learned regarding Classic is transferable to 2G.

[orange4boy]

Nice work. I only hope mine goes smoother. I started taking mine apart today.

Good tip on the autoingenuity scanner. good to hear that it works with the Toyota hybrid codes. If I have any problems once it's in I will buy one for sure.

Good luck with your move.

[tomfreed]

Originally Posted by yardman 49

Congratulation, Tomfreed. Great perseverance, but man, you are one crazy dude!

Remember though: perseverance alone won't get you through all situations. More information early on in the process can save you a lot of pain and grief, as you now know. I liked your comment about the "black forest".

Now that you've mastered the G1 Prius, you should try your hand at a G2. Maybe you can open your own Prius garage in Florida!

Best wishes,

Yep i was and am crazy enough to do what i did by becoming a used car dealer and taking on saving the world by buying, promoting and selling hybrid, biodiese cars, trucks. I tried to do my part to help with the global warming. I also found out the world, perception and people habits barely moved. Eventually it will when gas price gets over $5. As of now i am still doing and driving biodiesel car but no hybrid. Eventually i will buy G2 Prius since i know that they are very similar to G1 so repair is no issue for me. I am going to invest in the G2 manual before i tacke the next job. In actuality i know how to fix gas, diesel and hybrid cars, trucks so that about covers all out there for now.

Garage in Fl to fix hybrid, heck no way i am done playing with the used car business. What a pain in the rear with no financial compensation. I will be doing short sale investing specialize in luxury home and there are ton of them in Fl. It isn't over yet with the housing crisis and i want to get my share.\

Check out my ride with biodiesel that i make that puts out 80% less dirty than diesel fuel. 100% used processed cooking oil for the Benz, yes sir and mame! I have been driving and making biodiesel for almost 2 years now. Who says it doesn't work

[tomfreed]

Originally Posted by orange4boy

Nice work. I only hope mine goes smoother. I started taking mine apart today.

Good tip on the autoingenuity scanner. good to hear that it works with the Toyota hybrid codes. If I have any problems once it's in I will buy one for sure.

Good luck with your move.

Thank you. I read your post and it sounds you are going to need to replace the transaxle. Heck i could do it with my eyes close as i recollected i did 6 jobs that means 12 times in and out. I had other Prius beside this 01 when i was a used car dealer that i had to fix the transaxle issue. I have 3 transaxles but not sure they are any good but i am sure some parts are still good and i doubt you are going to fix it with part. I tried to remove the mg2 and man it is heavy that motor

If you need help with removing the transaxle and trick to get the air out of the coolant quickly let me know. Thanks to this forum, Bob and Patrick they gave me idea and info. to get my 01 fixed. I was done basically at the time i cried for help just that no body at this forum and myself knowing about resetting the replacement ecm to finalize the repair. Live and learn and die

[tomfreed]

Originally Posted by Patrick Wong

Hi Tom,

Nice work. I agree that it doesn't make sense to fix and resell the Classic Prius (esp when the car is not running and you don't know exactly what is wrong) because the market values are so low and the potential repair costs are so high = little or no opportunity for profit.

Most of what you learned regarding Classic is transferable to 2G.

I couldn't disagree with you on that. I already figured it out that the G2 is similar to the G1 but i do know they are better and more reliable and the battery is half the size and weight and is LI ION. NO Prius for me for awhile. Eventually i will buy a used G2 and who knows i might pick one up dirt cheap with seller doesn't know squat about the hybrid and gets scared of with the repair bill. Heck if there is a battery issue i will take it apart and just replace the bad subpack only instead of the the whole thing. I am trying to buy an RC battery charger on Ebay so i can revive the weak cell individually in particular the one i just took apart. Too late now that i bought the whole battery pack but at least for my own knowledge.

I will start selling the good subpack on Ebay to recoup my expense in the 01. It is a loss already financially on that car.