Last week the “Check Engine” light came on while I was passing. My morning commute is 40 miles on two-lane roads with limited passing lanes. When I can, I accelerate smoothly without a transmission downshift. But, when I need to get around, I get around, and this was one of those times, throttle down enough to call IMA and tranny downshifting. About half-way through the pass the engine seemed to lose punch and acceleration. In the old days, I might have thought “misfire in one cylinder” or “carb mix problem,” but on newer cars I frankly have no idea. My response to the loss of power was to add more throttle, close to flooring it. Engine responded, and I got around, but the “Check Engine” light started flashing after this second throttle. I’ve done similar passes before in the car’s 4000 miles with no problems.
Car seemed to run smoothly enough with the CE light on, though I did pull over within a couple of miles; by this time the CE light was steady on instead of flashing. Turned off ignition. Checked the owner’s manual. From some other car Check Engine experience I knew that the indicator can mean very bad news, or indicate a loose gas cap, or some “transient event” that trips the indicator requiring “fault codes” to be cleared and all will be well, or something in between. Owner’s manual guidance leans toward suspecting the worst. Restarted, check engine light still on, but smooth idle, no signs of a problem with other gauges, so I drove at 50 mph the ten miles on to work with no problems. Called dealer and talked to Honda service dept; I’m their first HAH customer, so they have no repair history for the HAH. His advice was to drive as little as possible and cautiously, watching for other signs of trouble, and to come in ASAP, which I did the next day.
Driving about 60 miles with the CE light on, I noticed that the ECO light never came on (I’ve been driving to keep it on as much as possible), although the battery charge and IMA indicators operated as before. Trip computer indicated that either the 6-cylinder mode can produce 32 mpg, or that VCM was still working even though the ECO indicator light was not on. I suspect the latter.
This was the Honda tech’s first hybrid work other than dealer prep checks. He reported that the diagnostic computer “could not communicate” with the car’s engine control module, so he was unable to observe a particular “fault code” that called the CE light. The fix was to “reboot” the control module and “reset” it. He advised me to monitor all gauges/lights closely for awhile since he could not tell whether the CE light was from isolated, transient event, or a sign of a more serious mechanical or computer module problem. He could find no cause for the CE light other than the glitch in the engine control module. He said the increased throttle for passing could have triggered the CE event, but should not have, but without a stored fault code, he'd only be guessing. All functions are back to normal since the reset; batt charge, ECO, and IMA indicator lights all back.
One added item, related to another thread here on HAH battery charging. The tech said the hybrid battery was low (my claim is that it was at least 3 bars, and more likely 4 which is what I see 90% of the time). We talked about “bars” of charge a bit, and it was clear that he did know how many “bars” the charge indicator had. I’m assuming he relied on a charge meter for his diagnosis. He said that the batt was now “fully charged.”
Indeed, all 6 bars of the charge indicator were lit when I started the car after the service, the first time I’ve seen 6 bars lit. I didn’t observe how he produced the 6-bar charge, but I don’t think it was from driving. IMA was very active in city traffic after leaving the Honda shop; within one mile the batt charge was down to 5, and within two miles, it was down to 4 bars again, where it has stayed except for some brief 2-3 bar times after hill climbs with IMA. I’m thinking there must be a difference between “full” charge and a “functional” charge, and that while 6 bars may be “full,” it’s not really a normal, functional batt charge level which in my car is a 4-bar charge.
Trip computer mpg and overall feel/sound/performance indicate the car is running as it was before the CE light incident. I don’t really have any questions here, but offer the info to add to the HAH knowledge base, and for comment and perspective from more experienced hybrid drivers.
Hybrids: 2007 Touring Prius Pkg 6/ 2006 Toyota Highlander Hybrid Ltd 4X4
Re: Check Engine Light
I purchased my HAH from David McDavid Honda (Frisco Tx) in Jan. I just mention that because I noticed your daily to commute to the DFW area and don't know if there is a connection for our cars as I also had the check engine light come on after a Mavericks game mid May.
I drove the car home without incident, but I too noticed that the Eco light did not come on, although the green and blue bars did. Auto stop also appeared to work. I was watching the trip computer and did not notice anything different.
As the first HAH with a problem at the dealership, the cable that connects the car to the diagnostic machine was cut - so I had to wait until the next day for them to have that part FedExed. They were finally able to hook the car up to the machine and did not find anything wrong. This prompted a call to the Tech Line (REF 1575182-Larry) who told them to clear the codes, load test the battery. They performed the test and all checked OK.
Then the Tech Line (expert Larry) told them to "perform a motor rotater position switch calibration" (I think they changed the factory specs to new spec which I believe are .123505 .6 118099 1.0).
Whatever they did, I guess worked as I have not had the problem reoccur, but it has been less than a month, so we will see.
I was really bummed because I had just returned from a trip from Austin where I had a terrific south wind and my instant mpg was around 37 mpg. They test drove it for 4 miles (probably floored it the entire time) which ended up dropping my mileage to 27 mpg.
I just mention that because I noticed your daily to commute to the DFW area and don't know if there is a connection for our cars as I also had the check engine light come on after a Mavericks game mid May.
Seeing this comment reminded me of a strange story at work. I work on a tactical radar system here in the Phoenix area. Our radar is pretty close to a fairly major road.
One day, about two years ago, a gentleman called and identified himself as someone from FoMoCo headquarters in Michigan. He wanted to know if we could disclose the frequency range our radar operates in. I told him I couldn't do that, as we weren't an FAA unit, but strictly combat, so it was classified. He then told me why he needed to know.
Apparently, various Ford products (I think they were mostly Land Rovers and Expeditions) had been reporting problems with their airbag warning lights around the metro Phoenix area. These vehicles were brought into the dealerships for troubleshooting, but the techs could never find the problem. After quite a few of these large SUVs had been bought back by Ford, their corporate headquarters decided assign a team to look into this problem.
The team found out that most of these problems were happening on a single stretch of road. After visiting this road, they saw our radar and did some tests. They concluded that our radar was setting off the airbag lights. Their fix was to change the frequency that their sensors operated on, and wanted to know our frequency range so that they could design a system around it. So, I put them in touch with our security personnel.
Another problem I've seen with vehicle electronics and our radar: I teach motorcycle safety. Our motorcycle range is within eyesight of the radar bunker. On two separate occasions, Yamaha R1 motorcycles kept stalling on our range. On the first day, we just had the R1 keep his RPMs up, since it seemed like it was stalling from low RPMs. On the second time that another R1 was out there, we noticed a pattern with this make of motorcycle. Watching the radar spin around, the bike kept shutting off when the antenna was pointed at it!
Apparently, many makes of vehicles have various components that rely on certain frequency ranges to operate.
Yes, all back to normal immediately after the "reset." I have had 2 other temporary "check engine" light appearances since this incident, each after near WOT passes, but the CE light went off and stayed off after 5 seconds or so. Wonder if the quarter-miler testers are seeing any unusual lights from WOT?
On most cars, the check engine light is directly related to a "fault" in the emission control system somewhere, and could be anything from a loose gas cap to a bad oxygen sensor, etc. If something is out of whack in that system check even for only a moment, the computer throws ups it hands and screams " wait a minute, something is out of the ordinary here...check engine light on. If it is a temporary glitch, the light will often go out on it's own if that particular part of the system checks out during the next "cycle", which usually consists of a preprogramed look by the computer at varied driving conditions over a set number of miles. I had a Volvo that was finicky about gasoline. If I ran Citgo gas from a certain station for many fill ups in a row, check engine light would come on. Change gas brand and station for a few tanks and it would go off. So it appeared the cause in that car was "bad gas". I don't know if it was contaminated with water or something, but whatever it was the emission control system in that car didn't like it. Since then, I try to fill up with "top tier" gas only, when I can...usually Shell regular for my HAH. If I had a Conoco nearby, I would switch to that.
The computer has to know what position the rotor inside the motor/generator is at so it can properly cycle electricity to the next set of windings, to keep the motor going.
From what I read about a dissected Insight inverter/IMA pack, Honda does not truly invert the DC from the battery into AC before it hits the armature windings on the motor, and they don't use brushes like most DC motors. Instead, they create a rotating magnetic field by switching full DC voltage onto to the "next" set of armature windings in the rotational direction, pushing/pulling the rotor around (the rotor has permanent magnets on it). Therefore the controller must know at all times where the rotor is 'pointed.' I suspect that is what needed calibration.
But that is a cool name for a BS-sounding way to appear important. Sort of like replacing the flux capacitor inside the logarithmic enclosure.