'03 Honda Civic Hybrid: total power out but then jumps and runs fine immediately

I drive an 03 Civic Hybrid. Twice, a week apart, while driving about 50, the speedometer goes to zero, then the power steering goes out and I lose power and momentum. The dash indicator lights go on like a christmas tree, engine still running, but car sluggish. I shut it off, and then get no power at all, not even hazard lights, and car won’t start. With jumper cables, it starts right up and runs like nothing happened. IMA and check engine lights are both on, and have been since I bought it three years ago. In those years, my gas mileage has been consistent (42mpg) and no other funny business. Dealer won’t work on it except to replace IMA and O2 sensors, which it has always coded for, and would cost the value of the car. What to do?

With the total loss of electrical power and the IMA light on, you’re looking at a hybrid system failure, possibly the battery pack, but may also include the drive motor/generator(s). These hybrids also have a small 12V battery, much smaller than a normal car battery, that has probably gone bad, as well. If you don’t like the dealer estimate for the repair work, and there may not be a qualified independent shop you can turn to for a second opinion, you may need to consider trading it in. You’re options are very limited.

Thanks for reply. The 12V battery tests fine. What are typical symptoms of the IMA system failure?

The IMA light being on is a sign of failure. Total power loss is another.

So it could have run consistently for three years with the IMA light on, and this new blackout routine is the actual IMA failure? Couldn’t this also be a simple short circuit or something? Would the diagnosis codes find that?

Only 42 mpg tells me the IMA battery pack is toast. I average 50 mpg in my Gen2 Insight.

The battery pack is the heart of the IMA system. With the IMA light on for probably longer than the 3 years you’ve owned it, the battery pack has been getting worse and worse until it can no longer keep everything running. With an ever weakening battery pack, the IMA system gets stressed out trying to keep the battery pack charged. Then, you get power failures.

You have to jump the engine battery to get going again. This car clearly has more than one problem.

What are the actual codes? HV battery deterioration has its own code. There is a 10-year warranty on those batteries.

Charge and load test the 12v battery and check the charging voltage. Replace 12v battery as needed.

Right now, every time you fill the tank, you’re spending more than the value of the car. ;-]

@BustedKnuckles‌ if that were the case, wouldn’t my gas mileage have been decreasing over time?
@rattlegas‌ the 12v battery is 3 years old but it tests fine, can I trust that result? Should I replace it anyhow since its an inexpensive chance to fix this? I will have the actual codes next week.
I was hoping to hear if this blackout is typical of IMA failure, or of something else, because I agree that there are multiple problems.

I can’t say what to do without being there. But having to jump the 12v battery to get the car started seems like it is a problem that should be easily diagnosed. Charge and load test the 12v battery and check the charging voltage. Replace 12v battery if it fails the load test.

Here is the 12v battery test results.

I have also just had a power steering problem with my 2003 Civic Hybrid. Clock flickered, the speedometer and rpms went to zero, and then the power steering failed. Car still had power, but no power steering. Turned the car off and back on and it seemed to work fine. This happened after driving the car 50 miles, before which it had sat for ten days. We’re starting to get colder weather where I live, so I wonder if that is effecting the IMA batteries only marginal ability to recharge. The 12v starter battery tests good, and the dealership mechanics are stumped as to what is causing this failure. The IMA and check engine light have been on since I bought this car in '07, and I’ve been driving it with no problems since then, opting not to replace the IMA batteries because of the expense. I’m wondering if the mostly deteriorated IMA system has now completely failed, maybe because of the colder weather. But it doesn’t make sense why it would do this after driving for 50 miles, when it presumably would have been able to recharge going up and down hills–if it was still functioning. Either way, dealer says I am looking at new catalytic converter and ABS brake sensor, on top of new IMA batteries, so it’s looking to be more expensive to maintain than the value of the car. Just wondering if you all have figured out anything additional to fix this power steering problem. Is total IMA failure likely the cause of the problem? How could the failure be intermittent?