mystery DTC, car starts but wont go into drive or reverse

Hi all,

I have a 2005 Prius. 3 weeks ago my dash lit up with warning lights so I took it to the dealer. They ran a diag and came up with
P3000/123
P0A80/C2311
"Vehicle has bad #4 battery block. Neesd HV Battery pack and HV ECU" I had just hit 150,900 miles and they wanted $3910 to fix it.

Given the cost I decided to fix it myself. After tracking down some cells and getting a HV ECU from a local junk yard I pulled out the hv battery broke it down, tested the two cells in the #4 block and replaced the low voltage cell. I then replaced the HV ECU. I put everything back together and everything started up fine and ran great.

things work well for 2 weeks then yesterday as I'm pulling into my driveway the main error indicator (the big red triangle cantaining a !) lit up. Needless to say I was dissapointed. I turned the car off and then turned it back on. At this point most all of the error indicators were lit (see attached image). I get a new error indicator on the multi-information display (the red car with the ! in it, according to the manual I'l supposed to take it the the dealer immediatly) The car started but the engine does not start. The car will not go into drive or reverse, just neutral.

I thought I may not be pressing the brake correctly so I spent some time making sure I was depressing the brake pedal fully when starting up. No change. I checked that hte break lights are working when I press the pedal and they are working correctly. I checked the brake fluid reservoir and it is filled to the correct levels.

A friend bought a innova OBD2 scan tool (his kid's cars break a lot) I borrowed it and hooked it up to my car. No error codes detected was what it told me. I was a bit perplexed. I switched to the Toyota enhanced DTC and then Readiness DTC and finally found some codes:
P0300
P0171
P0172
P000A

I found what looks to be the 2004 service manual online in an open directory http://zeroreality.net/prius/repair/ (enjoy while you can)
While I don't find P000A I do see the other 3.

P0300 (05–157)
Random/Multiple Cylinder Misfire Detected

• Open or short in engine wire harness
• Connector connection
• Vacuum hose connection
• Ignition system
• Injector
• Fuel pressure
• Mass air flow meter
• Engine coolant temperature sensor
• Compression pressure
• Valve clearance
• Valve timing
• PCV hose connection
• PCV hose
• ECM

P0171 (05–143)
System Too Lean (Bank 1)

• Air induction system
• Injector has blockage
• Mass air flow meter
• Engine coolant temperature sensor
• Fuel pressure
• Gas leakage in exhaust system
• Open or short in A/F sensor (bank 1 sensor 1) circuit
• A/F sensor (bank 1 sensor 1)
• A/F sensor heater (bank 1 sensor 1)
• EFI M relay (integration relay)
• PCV valve and hose
• PCV hose connection
• ECM

P0172 (05–143)
System Too Rich (Bank 1)

• Injector has leakage or blockage
• Mass air flow meter
• Engine coolant temperature sensor
• Ignition system
• Fuel pressure
• Gas leakage in exhaust system
• Open or short in A/F sensor (bank 1 sensor 1) circuit
• A/F sensor (bank 1 sensor 1)
• A/F sensor heater (bank 1 sensor 1)
• EFI M relay (integration relay)
• ECM

I was hoping for something a bit less vague.

So thats where I am right now. I have the indicator lights as seen in the attached image. The car powers up but the engine does not start. The car will not go into drive or reverse. I don't know the difference between the standard DTC and the readiness DTC

Any ideas?

 

I had assumed (always gets me in trouble) that the 12v battery was good and connected since I had dash and brake lights. Which systems do these functions run on?

I have not cleaned the MAV sensor or the air intake, I know very little about working on these cars. I'll gladly take all the advice I can get.

thank you very much for your assistance.

 

To everyone that suggested a look at the 12v battery you may have been on to something. Patrick, the headlights were dim in IG-Off. The voltage is under 12 in IG-On and dropped below 11 under load. Looks like I'll be installing a new 12v battery.

I replaced the HV Battery ECU in the back. I did not program the immobilizer ECU.

I'd have to agree with those of you expressing doubts about the applicability of the DTC. After reading through the manual of the innova it seems the readiness DTC are supposed to be emissions related?! I'm smelling red herring.

 

I put my battery on a 4 amp charge. The charger I have listed the battery charge at 25%. 5 hours later it still never made it past 75% (it's not very granular, 25%, 50%, 75%, and 100%). I got tired of waiting and put the 12v battery back in.

I was pretty excited when the car started up and ran normally. Yeah!

Then I was a bit bummed out when the car did the same thing as the first time, sudden errors and then would not go to READY from IG-ON. I figured the battery is toast and I'll be getting a new one tomorrow. I decided to try the Innova for DTC. I found one this time.

P0AA6 - Hybrid Battery Negative Contactor Circuit Stuck Closed.

Unfortunately the innova only gets DTC, no info codes. Looking at some of the previous posts on here regarding this DTC looks like it's most likely I've got something wrong with how I reassembled the HV battery.

I cleared the error and was able to operate the car normally for a few minutes and then it was back to the error. If we assume for a moment that I didn't end up with a wire touching the frame is there a component that would give this DTC?

This DTC is not in my 2004 service guide. I think I read somewhere on this site that it was new to 2005, is anyone aware of an applicable DTC in the 2004 guide?

You've all been a great deal of help. thanks.

 

Just telling you what I read in the innova, interesting that it's wrong. I guess there are no guarantees if your not using the correct tester.

So I think I "might" have found an issue, please see the attached images. Just not certain if it's the cause or the symptom.

Looks like I'm buying a new Relay. As I was taking the connections off of the #2 relay I noticed the negative side was not very tight, finger tight at best. As you can see in the pic the #3 pos terminal is damn near welded on. So how plausible does this sound, could I have not tightened up the terminal connections enough and over the course of driving it for a week the loose connection finally cooked the relay?

The rest of the HV battery all looks fine. Could a problem with the 12v have caused this? Could there have been another component that is bad and would have caused this?

 

It appears that you were correct again Patrick. After putting in the new relay, putting the HV battery back together and giving it a try I end up with a nearly immediate P0AA6.

I disconnected both frame wire connectors from the converter inverter assembly and then tested for a short between the wire and the shielding. The uncooked wire showed open, the cooked wire has almost no resistance. Looks like I melted the insulation enough that the shield is now contacting the wire. I hate it when I cause my own issues.

Anyone got any tips on doing a frame wire replacement?

 

Unless I'm missing something the wire leading from the main relay #3 is a portion of the frame wire. The top down image I attached in post #14 shows the wire (the one one the left specifically) and terminal I'm talking about. My test was removing both of those wires from their posts and then disconnecting both wires from the inverter. At the traction battery end, with the wire disconnected at both sides, I place one lead on the eyelet and the other on the crimped shielding. The good wire is open, the bad wire is short.

As far as I can tell those wires are one assembly and run all the way to the inverter. WIRING & CLAMP. Fits: Prius | Village Toyota Parts is that not the case?

Looking over the steps involved in replacing it in the service manual, I'm very open to suggestions.