New codes for old part deu

Go into your profile and change it to #9 -- or Adv. Technology


In another thread, adric22 mentioned that the ICE would spin but not start if the HV battery was at too low SoC. Have you tried putting close to a full charge into the battery? Does the ECM look for a particular RPM before opening fuel injectors?

All I can think, along the lines of a failsafe theory, is that when the HV battery codes, the ECM ignores information coming in (such as RPM, MAF) and opens everything up to make sure that the engine stays running. Of course, once in this state, it can't charge the HV battery due to the code. You have to clear the code and turn the car off to reset the system main relay. Catch-22.

You are soooo close to figuring this out. I wish you were close by.

 

Does that mean the SMR opens when the code is displayed? (I would think even if the ECM begins injecting fuel at that instant, it would be touch and go whether the engine starts if the cranking power has just dropped out.)

I wonder if it's possible to send a 'clear codes' while the ICE is running, and see whether charging resumes. Maybe the OP has already tried it. Long shot, but the sort of thing I might try anyway.

-Chap

 

That's what happens on Gen II, relays pop open and even a code reset will not close them again while the car is running. Can't say for certainty that it is the same on the Gen I SMR.

 

That is a difference of ~10% which is more than enough for the traction battery ECU to decide that you have a failed module within. There should be no more than 0.2V difference among the 38 modules.

 

To go further with the battery. If it is not strong enough, then it may not be able to spin the ICE fast enough to suit the ECM. It is possible that the ECM looks for a particular RPM to open the fuel injectors. Look at adric22's post here, maybe even pm him for advice.

http://priuschat.com/forums/generat...s-will-start-run-30-seconds-then-stall-2.html

A NiMH cell should hold 1.6V after a charge. Definitely, if one module reads 1V less than the rest, it has a bad cell and needs to be replaced. If you have battery modules that you suspect are bad, then it is worth replacing them. I think it is worthwhile to take that step before buying a fully refurbished battery from them (ReInvolt).
01-03 Prius Battery Module 7.2 volt NIMH | eBay

 

I agree that the engine ECU may have some logic within that prevents the injectors from being pulsed until the engine crankshaft rotation speed is sufficiently high.

I think it is dangerous to attempt to charge the Prius traction battery to 1.6V per cell (which implies 9.6V for a Prius traction battery module.) 273.6V (or 7.2V per module) is the "nominal" voltage rating and I recall seeing ~320V when the battery was reasonably charged, when I owned my 2001. Hence, I would suggest no more than 8.4V per module or 1.4V per cell; while keeping the modules under compression to avoid their physical expansion and possible explosion.

I also think that Dirk's battery has some failed modules that need to be replaced, I doubt that the discharging/recharging process will help them.

 

The "few" modules at 13.4V are likely to be bad.

 

My bad, I meant 1.4V/cell, 8.4V per module, 16.8V per pair.

 

Dirk, I can't think of another case here that has been more perplexing. You've covered, I think, everything that can cause 3191: MAF, throttle body, low HV battery, bad fuel, spark plugs, coils, etc. By far, the most intriguing aspect is that the engine runs after a fail safe trigger. To me, this implies that some sensor is feeding the ECM garbage, but the fail safe causes the ECM to go back to pre-determined settings for e.g. the injector pulse width. If you pull up the freeze frame data, is there anything out of the ordinary?

Is it possible that the injector pulses are too short rather than non-existent?