Why won't my hybrid start or go into Ready mode?
The most common cause is a weak 12-volt auxiliary battery, not the big hybrid battery. Hybrids use a small 12-volt battery to power the computers that start the hybrid system; when it's weak, the dash may flicker, the car won't go into Ready mode, or nothing happens at all. A jump to the 12-volt system usually gets it going, and a new 12-volt battery is the usual fix.
Signs of a weak 12-volt battery
- The car won't go into Ready mode when you press the power button
- Dash lights flicker or warning messages appear briefly, then the car shuts down
- The key fob or door locks don't respond
- The car has been sitting for a week or more
- The 12-volt battery is more than about 4 years old
Why hybrids depend on it
The 12-volt battery doesn't crank the engine; the hybrid system does that. But the 12-volt battery powers the computers, relays and contactors that wake the hybrid system. If its voltage is too low, the car can't connect the hybrid battery, and nothing starts.
What to do
- Try a jump to the under-hood jump terminal, following your manual.
- If it starts, keep it in Ready mode for 30 minutes or so, then get the 12-volt battery tested.
- If it doesn't, call us.
We test the 12-volt battery and charging, and replace it with the correct type; many hybrids use a specific battery design because it's mounted inside the cabin or trunk. We've gotten hybrids running again on the same day, including a Lexus CT 200h that came in not running.
From drivers who came to us
My Lexus CT 200H was in dying need of a new battery after nine years with over 146K miles… They got my car up and running by replacing a new starter battery and rear shocks since they were leaking by the end of the day.
I had my 2009 prius "check engine" light on that somehow caused smog test failing… The check engine light issues were fixed. Smog test was passed.
Excerpts from verified customer reviews on Yelp.
More questions
Where is the 12-volt battery on a hybrid?
On many hybrids it's in the trunk or cargo area, or under a rear seat, rather than under the hood. Most have jump-start terminals under the hood, often in the fuse box. Check your owner's manual before jumping.
How long does a hybrid 12-volt battery last?
Often 4 to 6 years. Hybrids that sit for long periods or make very short trips can drain them sooner.
How long does the main hybrid battery last?
Many last 10 years or more and well past 150,000 miles. In California, many hybrids carry a 10-year, 150,000-mile warranty on the hybrid battery; check yours.
Can I jump-start another car with my hybrid?
Most hybrid manufacturers advise against it, because the 12-volt system isn't designed for it. Check your manual.