Hi folks, looking for guidance to make sure I'm on the right track. 2005 Prius, 190k on the odo. Friend was throwing it away so I basically got it for a steal. Was giving intermittent transmission code. Usually on long drives when the back was full. Led me to believe it was a heat issue and the battery. Former owner informed me he got that code a few times. Code never came when the back was empty. Former owner also had cells replaced. I got the hybrid battery code for a few blocks, used a trusted source to do cell swaps, code came right back. Took it back to him and after working on it he described it as a cancer and would need a full battery pack swap or full cell rebuild. Got a lead on a gen3 battery with low miles (2012, 110k on odo). Did the full cell swap and got recurring hybrid code indicating blocks 8, 11 and 13, with 11 being the repeat offender. Got another different gen3 battery, did the full swap again, and getting repeating block 11 as the guilty party. Reading more threads on issues faced with rebuilds, it seems another common culprit is corrosion on the copper contacts for the cells and wiring. There is a decent amount of corrosion across everything (the blue raspberry dust). Checking resistance with the fancy Autel, and it's always 0.02 across all blocks, no deviation. Was the same with the other full cell swap. Revving the engine in park, it's always cell 11 that drops the most. Is another possible culprit the copper contacts as well as the wiring? Probably take it out and clean everything this week.
Yes You are n the right track. Use vinegar and a toothbrush and scrub everything down to bare copper. 800 grit sandpaper for the bus bars is what I used. BTW. Wire Frame #2 at a toyota dealership for $85 saves you a lot of cleaning. while it is out I would inspect every cell and module for leaking, cracking etc. Clean your hybrid fan and make sure your temp sensors are put back correctly. Did you try clearing the codes and then re reading them? make sure you tighten the 8mm nuts to spec.
Thanks for that. Given the amount of corrosion, will probably call the dealer Tuesday and order a replacement and then save and clean these for future use. Cleared the codes and driven many times. The system isn't happy with something about cell block 11. Temp sensors are working and reading correctly. I broke one sensor on the swap and ordered a replacement from ebay, replaced and it's operating as intended. What's the spec on the 8mm nut for the bus bar?
48 inch pounds..... yes....Toyota states 48 inch pounds for the module fasteners, which includes the positive/negative terminals and the mounting fasteners that thread into the bottom of the module. If you really want documentation, I can hunt it down in the repair manual, or you can just google torque requirements for that size fastener (M5)
You will want to check the orange connector pins in the battery ecu for corrosion. I have many scantools, but when I want to monitor battery block voltages, I go for the Dr Prius app (with a compatible generic OBD adapter). That makes it easy to watch for high VOLTage DIFFerential between blocks (that would trigger codes.) In general, a "bad" (failed) module causes low block voltage on accel - discharge and high voltage on decel - charge. Posted via the PriusChat mobile app.
Dr Prius works with ios, just need a compatible OBD adapter. See the Dr Prius site for details. Posted via the PriusChat mobile app.
Since I really like incomplete stories on forums: This one has been a doozy, replaced the bus bar, car ran better, but was still getting the red triangle across three different blocks, but would take a while to set (usually 20-40 miles, before it was real quick, within minutes of driving or parked with foot on the gas), was giving on different blocks vs before (11 and one other before, 14, 7 and 5 the second time). Did a bunch of hills to make sure I was stressing and charging the battery (read that in other threads) Took out the battery to tighten to spec again (grabbed a torque wrench from the tool store), and the first one broke off). Grabbed a replacement cell from the local guy I was introduced to who does hybrid repairs out of his garage, and decided and test every single cell. Found three that were low (including the one I broke). Grabbed two more good cells from another donor battery that tested well, reinstalled, drove 120 miles yesterday, drove different routes to make sure I had some hills to climb, did a good amount of city and highway, and no pending codes on the fancy Autel for hybrid or hybrid control (yet). Putting back together as the other half wants the garage back. Gonna chalk this one up as solved for now. Going to charge and stress load the two cells that appear bad (need to borrow the fancy charges from a friend) and see what happens, and charge and test the rest of the cells from the other donor gen3 battery. Thanks for all the help folks. Greatly appreciate all the input/
