Hi Andy J, sadly your story sounds absolutely identical to ours! We have a 2004 imported Toyota Alphard Hybrid with exactly the same history, eventually requiring jump starting every time we used it even after we'd just driven 200 miles! We took it in to the Toyota main dealer a few times and, apart from putting their diagnostic machine onto it, they did nothing to investigate further or try and fix it. This is what the diagnostic machine showed:
• C1241 Low Battery Positive Voltage or Abnormally High Battery Positive Voltage
• C1256 Accumulator Low Pressure
• C1365 Acc Pressure Sensor
In the end, through this forum in fact, we got a tip to try Cambridge Hybrid Vehicle Specialists in Waterbeach near Cambridge which, by sheer good fortune, is only a couple of miles from us. The very pleasant owner, Ajay, said this was a known problem and often the cause was corrosion in a wiring loom that is accessed from somewhere under the front passenger footwell. Also, Toyota had not put the correct battery (our third replacement) in the vehicle. He has replaced and cleaned up the corroded area and given us a new (higher specification) battery. We've only just brought the car home. We'll see if this does the trick but Ajay said that before he replaced the wiring loom there was a drain showing on the battery (Toyota said they couldn't detect a drain at all) and now he has replaced the wiring loom there is no drain showing. Fingers crossed this may have solved the problem. I guess we'll only know if hasn't fixed the problem if the current souped-up battery becomes worn out from an ongoing drain. But if that happens I'll post again. We're feeling hopeful.
