06 civic Hybrid 133k miles. Stopped at gas station to get gas turned engine off to pump. All gassed up turn engine on and the IMA, CEL and Brake System Failure lights all come on. Couldn't take car out of park (safety mechanism i assume) and engine rumbles and stalls. Wait 20 mins, started car again - this time only CEL is on - no rumble no stall - I drive car to dealer. They pulled 4 codes all having to do PCM and IMA. They do a PCM update and call to say car is fine and ready to pick up. I come to pick up, and CEL is on again - they pull 2 new codes having to do with the "motor assist module" and the "battery? assist module". Leave the car again, now saying car needs a needs a new computer ~$900. I cant find anyone with a similar problem online. Could there be an alternative issue like loose wire or connection?

Might there have been issues I could point to while the car was still under warranty like an oddly inconsistent idle (idle would pulse between maybe 300rpm and 1000). This is also what it was doing when stalling out at the gas station.

Thanks in advance for any input.

 

I have exactly the same problem!
Did replacing the ECU solve the problem?

 

I suspect that a new ECU might be the answer. It is an expensive solution, so I would really appreciate some feedback on the following.

I have similar symptoms (specifically in hot weather). Dealer said IMA Batteries: I replaced them - no change. I replaced the whole IPU control pack and the IPU cooling fan (since it was "heat induced"). No change.

Specifically my full symptoms are:

1. Starts to “jump gear” momentarily as though it is being slipped into neutral and immediately back into drive. As it does this, gear selection indicator on the gear shift showing the lighted “D” will flash off and on synchronized with the “slipping”.


2. After 30 seconds or so, it goes permanently into “near neutral”, gear indicator lights stay off permanently, speedometer reads zero, average mpg reads “----“ and the brake fault light comes.

3. Another 30 seconds or so, electric steering fault light comes on. At all times brake and steering are fine.
Moving the gear shift up and down between Low and Drive has no effect, but moving into neutral changes it from “near neutral” to 100% neutral. (“Near neutral” means that it feels like neutral but will get up to 30 mph very slowly as long as the incline is less than 10%.)

4. Another 30 seconds IMA warning light comes on.


5. Eventually, engine stalls. If you put it in park at this point, it will not come out of park whatever you do.


6. Wait 5 minutes or so (in shade - until sun goes down in sun) and everything goes back to normal. Drive a mile and symptoms return, but progress more quickly this time. Wait 10 minutes and it will probably take 2 miles to goes haywire again. Wait until the car has fully cooled down and it quite likely will not happen again until you get back into slow moving traffic under a hot sun.


The "gradual systems close down" symptoms (especially if heat induced) would definitely indicate failure of the main electronic control unit, but dealer took me down the wrong path by saying that the diagnostics indicated that this was caused by the IPU system forcing such a low voltage (8V they said) on the 12V system, that it was bringing thge voltage down too low for the ECU to function properly.

I am now (after wasting a lot of money, but learning a lot about hybrids) forced to conclude that it is failure of the ECU that is bringing down the whole system.

ANyone have experience to support this?

 

Quick update on my problem:
I replaced the ECU with one from a crashed car last week. Until now, the car is running perfectly.


I had similar problems:
- When the engine was cold, I NEVER had a problem.
- I NEVER had a problem as long as the engine was running, and I didn't turn off the car (auto stop was working fine).
- When the engine (and the weather) was hot, I had often a problem turning on the engine after it was running. A lot of errorcodes where showing up (on my scangauge). One of them was "low voltage...?!", another one was "communication error on the CAN bus"...?!. Sometimes even the IMA light came on.
I was still able to turn on the engine (sounded a bit strange sometimes), but I was always unable to move the gearshifter.
- Sometimes, disconnecting the 12v batter helpt. Sometimes I had to wait for hours to let the car cool down.




After replacing the ECU with a used one, the software needs to be updated and it needs to be ajusted, so it works with the existing keys (according to my Honda dealer, the Honda diagnostic device needs to be online to do this, my dealer was struggling with that.....)


If someone is intrested, I think I have pictures of the errorcodes...

 

So, are you saying that when you replaced the ECU, your keys did not work, so you had to tow the car to a dealership for reprogramming?

I am about to replace the ECU in a 2006 Civic Hybrid and want to get an idea of what I'm in for...

Thanks

 

If by ECU, you mean PCM - the shrouded computer in front of the 12V battery, then yes, it has to be reprogrammed.

 

@Bigfoot100: No my dealer was replacing the ECU. So, the car was already in the shop...

 

I had a spare PCM (Powertrain Control Module) laying around, and Honda charged me $130 to reprogram it. If you don't, the immobilizer will activate as the key transponder and coded VINs on the other control modules don't match. Honda charges an exorbitant amount to replace the PCM, so you should buy a replacement yourself and just take it in for programming (they're running about $100 on eBay at the time of this writing). Also, note that the Civic Hybrid doesn't have an ECU; instead it has an integrated PCM that runs the engine and transmission, and controls the CAN-bus that tells all the other control modules (power steering, power brakes, IMA, BCM, dash, etc.) in the vehicle what to do.

YES! I was making a long delivery from Ohio to Florida, and in Georgia, my 2006 Civic Hybrid suddenly did this! It had done it briefly a couple days earlier at a gas station, so I knew that I couldn't restart the engine or get it out of park if I stopped. But I thought the problem was due to a low 12v battery (I had left the headlights on at the gas station for some time). Now that I think of it, I've had a 12v battery so low it couldn't start, and all the dash indicators continued working normally. Anyway, you described this failure behavior nearly perfectly:

1. While driving, the 'D' indicator goes out and the car revs to 3000-6000 RPM. At 60+ MPH, you still have power, just with crazy high engine RPM. At 35-59 MPH, the clutch is slipping and you have limited power. At lower speeds, the clutch "pulses", giving you bursts of power. At a stop, the engine drops below 500 RPM and stalls if you don't give it gas.
2. Within 0.5 - 2 seconds later, it either:
   • Corrects itself and goes back to normal operation. At 60+ MPH, the RPM slides back down to normal. At 35-59 MPH, the clutch violently snaps back into lockup. At lower speeds, the car lurches forward. A couple seconds later, the 'D' indicator will light back up. It could stay in normal operation, or it can go back to step 1 at any time, usually in 10 seconds to 10 minutes. It is definitely heat sensitive!
   • Continues failing. One by one or immediately, the fuel economy/temperature gauge goes blank, the speedometer goes to 0, IMA goes blank, "Brake System" lights up, "Power Steering" lights up, the odometer freezes, MPG on the trip counters goes to "---". The car persists in driving as described in step 1 and never recovers on its own.
3. The IMA appears to keep charging the 12v battery. Power steering and brake continue to function, despite the failure indicators. The only way to recover normal operation that I have found is to turn the car off and let it cool down. This takes anywhere from 10-30 minutes. Unless you kept driving it, in which case it could be hours. You can check progress by turning on the ignition and checking to see if the 'P' and 'D' indicators light up immediately (when both are lit, the PCM is testing the CVT control circuit). If not, turn the ignition off and wait some more. Once it starts working again, you may get anywhere from seconds to unlimited operation, depending on the temperature and alignment of the planets.

In my case, I was doing 70 MPH on the freeway and the car kept driving fine, albeit at 3500-5000 RPM, so I trudged on as I had a time to make and didn't want to be stranded 800+ miles from home. About 30 minutes later, I started losing power and the engine went to 6000 RPM. I let off the gas and pulled over because I didn't want to damage the CVT, and something was obviously slipping. RPM fell to about 3000 when I let off the gas, and followed my speed all the way to zero. As soon as I stopped, I saw wisps of smoke coming out from under the hood. I lifted it to see what was hot, and it was the CVT smoking! It kept smoking for well over an hour, although the fluid was still clear and smelled OK. My 2006 HCH has 400,000 miles on it and the CVT fluid was last changed at 300,000 miles. After an hour and a half, the car cooled sufficiently that the PCM started working again. I started and tried to move the car, but it was very weak. The IMA battery was also completely dead, but before it could start charging, the PCM crapped out again. At this point I abandoned the car and got a rental to finish the job.
A day later, I came back to my car and tried again. The PCM was working normally, and I revved the engine to 3000 RPM to charge the IMA battery. After a couple minutes, it was charged. Then I tried to move the car again. Whoa, the CVT was nice and tight again! In fact, as I drove it, I realized that the CVT has never been this "tight". Tight (like a manual transmission) is good. Loose (like a slushy automatic transmission) will damage things with slippage and reduce fuel economy. Based on the fact that the CVT wasn't destroyed, I decided to try to drive my car home. I got about 10 miles out before the PCM failed again. I waited for the car to cool down and made it another 10 miles. Then 3 miles. Then 5 miles. Then evening started approaching and we had a cool rain shower. Next thing I knew, I was driving and driving! 200 miles later, I stopped for gas. At the gas station, due to the heat buildup (lack of forward airflow to keep whatever cool) the PCM stopped working again. This time I had to wait over 30 minutes before it started working again, and only made it a quarter mile before it quit. Another 30 minutes later, and I was back on the road, traveling north. After many miles, I had to stop and rest. Here in North Carolina and at night, it was cold. The car gave me no further trouble the remaining 400+ miles home.

After failing repeatedly, it had the following error codes:

• P060A (ECU11): ECM monitoring processor performance problem
• P16D5 (ECU11): F-CAN malfunction
• P16D6 (ECU11): IMA-CAN malfunction
• P2413 (ECU11): EGR range/performance problem
• P0A7F (ECU01): Hybrid battery pack deterioration
• P1570: (ECU01): Battery module individual voltage problem
• U0100 (ECU01): Data bus ECM A (ECU11) no communication
• U0100 (ECU02): Data bus ECM A (ECU11) no communication

ECU01 is the IMA. ECU11 is the PCM. I don't know what ECU02 is. Prior to this, it only had the EGR and hybrid battery deterioration errors. Further diagnostics of mine revealed that the PCM is completely shutting down except for the ECU (engine control unit) part of it, leaving the CAN-bus dead and letting the CVT freewheel with no control signals. The CVT uses three solenoid control signals to operate: Drive pulley pressure, driven pulley pressure, start clutch pressure. It appears that more solenoid drive reduces the pulley pressure (and thus, belt tension), and more solenoid drive locks the clutch. So basically, no signal maxes out the belt tension at mid-ratio and leaves the clutch disengaged completely, causing the CVT to fallback on the failsafe hydraulic clutch circuit. No wonder it overheated... The hydraulic pump was probably working at 800psi, the clutch was on the verge of slipping continuously, and the belt was probably tensioned at a whopping 4000lbs, moving very fast with the engine at 4000 RPM at mid-ratio.

So I replaced the PCM and had the local Honda dealer reprogram it. My questions are...

1. Did replacing the PCM solve the problem for any of you guys? As far as I can tell, the problem only manifests in hot, humid conditions, which I am unable to replicate here. And I am afraid the problem isn't fixed and don't want to be stranded somewhere again. I've driven another 300 miles since and the car has given me no trouble.
2. I know the CVT has no temperature sensors on it, but does it have some sort of internal thermal protection? It basically started clutching on me when it overheated, but seems to be working better than ever now. Between being overheated and the replacement PCM, it's not jerking at all when starting from a stop, and I'm getting great mileage. I have never felt a Civic Hybrid not have a little jerk when starting out, and I've test driven and ridden in several! I am planning to change the fluid and filter, but don't want to pour money into a CVT that's going to fail, if in fact it got damaged.

 

You put so many words in there, I'm kinda lost, but I'll respond to the actual questions:

1) in the one instance I'm personally aware of, a failed PCM would work intermittently and appeared to be heat related. Car dies, pull over, wait, start and repeat. Replacing the PCM eliminated this. If your PCM has performed normally in dry conditions for an extended period, then the problem is likely fixed.
2) Mistake #1 is the fluid is supposed to be changed every 30K miles. At 400K your CVT is on borrowed time. Honestly, it was on borrowed time at 200K. The only defense against a CVT failure is fluid replacement, which should be done every other oil change or about 15000 miles. No one replaces the filter. $30 in Honda CVT fluid doesn't seem like a big risk to me; however, if you plan to EVER drive it again, NOT replacing the CVT fluid with 100K miles on it is just dumb. Additionally, given that you KNOW the fluid hasn't been changed for 100K, a flush is in order. My version of a flush is 3 drain/fills on 3 consecutive weekends with driving in between. You're replacing a little over half the fluid with each 3 qt change. 3 changes replaces 90% of the fluid.

 

Hi guys..

i have 2006 Civic Hybrid, ran into problems and i solved it and also echo many of what you have stated above.
my story:

combi meter lit up like Christmas tree.

when cold the car ran ok, but with heat soak or long idle, the car fails and these codes are present

P16D6
P060A
P16D5

i confirmed by having ice water and when the car failed, i cooled down the ECU with the ice water and it fixed the car temporary, then it over heated again.

ended up reading more on the net and found a used ECU.
got the keys reprogrammed and all is fine.

sounds like many of us have had this problem.