When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Mode $06 data is information the OBD II system tracks and compiles on “noncontinuous” monitors. It is tabulated in hexadecimal code (a base 16 number system that uses digits 0 to 9 plus letters A through F), which is the computer language that the PCM uses to manage things. The “$” symbol means the data is in hex code, not ordinary decimal numbers.
The fact that Mode $06 data is in hex code means it has to be converted into familiar decimal values for us to understand it. This requires some math and conversion factors, or scan tool software that can do the translation for you. You also need a reference chart from the vehicle manufacturer that identifies what component or system test each line of code refers to, and what the acceptable range of values are for that particular test. Only then can you determine whether or not a particular Mode $06 test value is good, bad or borderline.
For example, when I was having misfire on my cyl 3 it would show something like:
val 15 min 0 max 65535
So I was having 15 misfire when allowed values were 0 - 65535.
My scanner does the hex conversion
@JDFit Dude, very enlightening, thank you! I've been meaning to learn more about the computer side of troubleshooting. You explained it very well too.
The PCV valve is located
See the hose clamp? That's it! Kinda cramped
This is wire harness routing bracket is in the way. One bolt and slide it to your right. nothing has to be disconnected.
You can pinch that hose while the engine is idling. If pinching it doesn't affect idle, it's clogged. If you do decide to remove it be sure to hit it with wd40 or penetrating oil beforehand. It uses the same crush washer as the oil pan drain plug, and it's TIGHT. like 33ftlbs..
Cant recommend a service center :/
All these electronically operated devices should send codes if operating outside of range..you dont have like, one of those lifetime oiled air filters, do yuh?.. or any electronic devices that stay hooked up to your obd2 port for an insurance discount. anything like that?
Just need a 17mm deep socket. You can even take the old one out and clean it if it is still good. Just make sure that you don't over-tighten it because they will break (ask me how I know).
Sorry to hear you're still having misfire problems. I also apologize that my suggestion of a possible failing fuel pump didn't pan out and correct the problem. The other thing I would suggest checking, would be the major grounding spot at the top of the transmission, under where the battery and tray sit. There are a number of ground wires that come together there and are grounded with a bolt into the transmission housing as I remember. I would undo the grounding bolt and wire brush the ends of the wires, wire brush the ground spot and the bolt itself and make sure of a good ground. If the ground bolt is loose or the ground wires have rust on the end terminals that could lead to major issues.
One last thing I would check are your battery terminal connections. As I remember, a member posted here that some random electrical problems came up on his car. After much checking, he found one of the battery terminals was either loose, or one of the terminals had been over tightened and the terminal had cracked. The loose battery terminal was the cause of the electrical problems. Just a thought. Good luck.
I am infinitely grateful to all of you guys chiming in and offering helpful suggestions and solutions.
I have a couple of updates but none are the good news I am hopeful for.
No worries Dan, the fuel pump is another thing I'm saying was preventive maintenance. Battery is brand new, and yes, I've been exposed to weird faults due to corroded or loose battery terminals. Those can create some very interesting light shows on your dash!
1. I tried to look at the PCV valve, it was a very simple process, thank you very much Pyts! I removed it, checked it, cleaned it, reinstalled it and no change at all. I'll put that under preventive maintenance, haha.
2. I was looking at the data to see if there was something there I was missing. I am thinking that maybe the MAF and MAP voltage ranges or operating ranges are a little off but I am not sure what they're supposed to be... So I was monitoring things and idling the car and something really weird happened. I was looking at the misfire counter, not the $06 anymore but the more specific live data ones. I was looking at them while idling. I blipped the gas to see if anything changed and I was getting 1 more misfire on cylinder 4 every time I was blipping the gas. Blipping fantastic. I have no idea why this is haha. The misfires have all kept pretty random to all cylinders. I am not sure the catalytic converter is clogged. I hope it isn't.
I am actively seeking outside help in my area so hopefully I'll find a shop or someone that can unlock the misfire mystery!
2. I was looking at the data to see if there was something there I was missing. I am thinking that maybe the MAF and MAP voltage ranges or operating ranges are a little off but I am not sure what they're supposed to be... So I was monitoring things and idling the car and something really weird happened. I was looking at the misfire counter, not the $06 anymore but the more specific live data ones. I was looking at them while idling. I blipped the gas to see if anything changed and I was getting 1 more misfire on cylinder 4 every time I was blipping the gas. Blipping fantastic. I have no idea why this is haha. The misfires have all kept pretty random to all cylinders. I am not sure the catalytic converter is clogged. I hope it isn't.
Just a question, what number are you getting on the Mode 6 for the misfire? During a cycle, is it 1 or 100, etc? My scanner shows the count, and it also shows the last 10 cycle's Average count. If you are getting low numbers, 0 here, 1, there, 2 occasionally, I'd consider that not to be something to worry too much about. If you are getting 75, 100, etc. Then yes, big issue. What kind of numbers for misfires are we talking about here per cylinder per a mode 6 cycle?
Great question, I am now looking at the live data and that's where I've been seeing the misfires happen but here's some screenshots of the different data I've been looking at including some older $06 data.
This is interesting.
You know, I had a crazy weird fault on my mazda project that was only recently resolved.
Electronics would freak out when pressing on the gas pedal. It had a cable operated throttle, too, so i was able to verify that it also got goofy when twisting the throttle on the throttle body. It would cause all gauges in the dashboard to sweep and the car would not accelerate, but it wouldn't stall either! Originally the fault was very rare, but the more I worked on other stuff, the more I started the engine, the worse it got! As if the PCM was learning to make the car run worse. After checking and replacing a number of things to no avail...
Checked:
injectors, jumped to verify
intake & vacuum stuff
timing chain
voltage from a number of sensors like throttle position, blah blah blah
cleaned all electrical grounds in the engine bay
Replaced:
pcv
spark plugs
inline fuel filter (I cut that open too. It was fine despite the car having had 250k miles and a *seemingly* original filter.)
transmission range sensor/neutral safety switch
PCM
I also stripped the wire harness in some areas that looked not so good, but I couldn't find anything obvious.. and I've learned not to mess with wires unless they're obviously broken/shorted. Everything I read claimed that the fault would be bad electrical grounds..
I went out and purchased a thingus called a radio interference capacitor as a last effort. Because I had the service manual I was aware that that component was missing since I received the car.. It ran okay when it arrived, it just got worse over time.
My writing is going down hill so I'll just get to it. It was a little capacitor that assisted the ignition system. My understanding is rough, but I believe it stores electricity either for or from the ignition coils which amplify the stuff. I guess the coils were generating electrical interference or some kinda bs, and that was screwing up computer communication.
Problem solved and hasn't come back in a couple weeks.
Based on your most recent update I'm inclined as you are to take throttle related electronic functions under a microscope. I'll try and pull some related sensor voltage signal info for yuh.
You can back probe with T pins while the engine is running. picked these up from Michaels.. Alligator clip multimeter probes would be a nice addition too.
I am trying to test out the MAF sensor for faults and/or false readings so I'm driving with full data recording and such. I'm learning to use the software so I'll have to dedicate it some time.
This afternoon I went for a spirited drive and then recorded my idle data after the drive. The pictures here are the data on the car at rest, idling in Park.
I'm trying to find relevant ranges of function for the MAF and also the MAP if anyone knows what those are since that would give me a reference point.
Last but not least, I can replicate the stumble going from 1st gear to 2nd gear around the 1600RPM mark and until the 2000RPM mark when it stops. Other times is mostly when I'm merging onto the highway or trying to pass someone that the bucking and loss of power starts.
look into the throttle position sensor for having a bad spot as a potential. Usually
Originally Posted by Eitan Benjamin Feldman
Hey guys! Been a long time member but never posted before until now.
I drive a 2013 Honda Fit Sport Automatic Transmission with 125k miles on the clock.
I am posting because I am at my wits end with random misfires that usually come on when the engine is under load, when I am merging onto a highway, pulling away, etc... The engine seems to buck, lose power, stutter, shake, etc when regular acceleration is applied. It is quite annoying and sometimes dangerous. If heavy acceleration is applied the engine does not do this and car flies everywhere but I don't like to drive like a maniac all the time.
If I check the $06 with the Scanner, misfires are quite random and can occur on any and all the cylinders. NO check engine light or flashing of any lights on dash as the bucking or loss of power occurs or afterwards.
I followed the advice in this forum and replaced spark plugs and coils, using different high quality units. Currently running NGK Ruthenium plugs and NGK coils. When checking for misfires, they're almost always random and do not point to any cylinder in particular. Have tried 3 different sets of coils and problem persists.
I am at my wits end because of the many different things I have tried to no avail. I don't know what else to do. My dad suggested corroded grounds or corrosion at the ECU but I can't find any obvious signs of either of these. Battery is one year old and both it and the charging system have been tested.
The car has a somewhat comprehensive service history with some recent services.
Under my ownership the car has received:
-Fresh synthetic oil change
-Fresh synthetic AT oil change
-New Ruthenium NGK Spark Plugs
-New NGK Coils
-Throttle Body Clean and Idle Relearn with Scanner
-Valve Adjustment
-New Air Filter
-EGR Clean
-MAF Sensor Clean
-New Denso Upstream 02 Sensor
-Lots of injector cleaner, BG cleaner, etc...
-Premium gas tried as well.
-Checked and cleaned fuel pump filter, no obstructions.
-Checked injectors with Scanner, shutting them off individually.
-EVAP system tested, passed test.
-Ran Lambda Test, all cylinders passed.
Only things that have somewhat come out is that at idle, the engine runs slightly lean, thought O2 sensor was at fault. Replaced O2 sensor, no change. Engine still slightly lean at idle.
Other times when the engine will stutter will be if I make a turn and then try to accelerate coming out of the turn, the car will misfire, stutter, lose power, etc....
Engine idles more or less OK with only slight vibration.
Do any of you have any other suggestions or places to look? I can't get rid of the loss of power and it is driving me absolutely crazy. Any other tests I can try?
as a general point i would be questioning things that can involved in a complaint. Clearly we need not question the brake lights as a potential, as an example. So lets think about the complaint conditions as described. Idle slightly lean or low first! Ok, so lets give some thought to the idle system on modern cars for the most part. All fuel burning motors need a mixture of fuel and air in a specific blend. Todays cars run F.I. systems. The air is controlled via the foot generally. However not in total! No at Idle the engines computer makes fine adjustments to allow warm up, outside air temp trim, air density via elevation needs etc . Your throttle body regulated via a bypass air to do all this. This device often gets nasty over the years from E.G.R. system, C.C.V build up etc and they fail to function right. All internal combustion engines of modern times can suffer this. The good thing is most times they can be cleaned with a can of Throttle body cleaner and patience. As to your foremost complaint of a Miss/ sluggish response A few thoughts. A lot of our minds jump to fuel as the only source for this though we need to understand the engine expects to get a instantaneity sent signal in the computer calling for your foots response.. Fuel timing must match as must the timing be picked up to respond instantly. Only air supply is at your control by the pedal! Your engine definitely was sent more fresh air, just no guarantee of matching fuel delivery or spark delivered as demanded. A worn timing belt system can cause this type failure so don't get roped into fuel alone.
I found a troubleshooting procedure that gives some insight into the MAF's wiring. I also found that it should give a reading of 4.7-5.7gm/s when the engine is held at 2500 +/-100rpms for 30 seconds.. But I think it should throw a code for just about anything wrong with it.
Oh btw, did you ever say if you had an aftermarket air filter? Like one of those lifetime oiled fram ones..
I decided to let someone else do the searching around and they totally did!!!
It was something simple......
When I first got the Fit, I installed some LED brake light bulbs. I installed quality Phillips units. I forgot about them because they were working great. EXCEPT they were causing interference in the engine management system. The engine was receiving some weird signals from the brake switch and lights because of the newly added LED tail light bulbs.
NOOOOOOOOOOOOOOOOOOOOOOOOOOOO!
Replaced the tail light bulbs with normal halogens and the problem magically went away. An expensive lesson to learn.
Yes, that complicated and that simple.
In the 2013 models they added a new brake system to the Fit that would stop unintentional acceleration happening. This system works with the brakes by cutting power when the brakes are applied and not allowing the engine to rev.... Causing most of the bucking and such by cutting power to the engine......
If you have a 2013 and are experiencing bucking, stalling, loss of power, etc, this is another avenue to explore...
An expensive lesson for sure but an informative and frustrating one as well.
Thank you to all of you who chimed in to help and try and sort this mystery. I owe you guys!
That's awesome!! This thread did not disappoint. You did so much, and I'm so glad that you had the confidence in your work to keep looking to the next thing. And what's more, you actually weren't wrong! I'm so curious as to how this fault was found. The problem was with hard acceleration, but the brake system interfered because it was wired to interact with ignition.. how the heck would that be isolated when brake activation wasn't involved with triggering the fault?
A misfire caused by brake lights. I wonder if this could have been figured at all without your having eliminated all those other potential causes.
They were initially thinking that it had to do with the ABS system or the traction control system due to the engine cutting power. They were able to replicate the symptom on a stop to turn, left or right. The engine would cut off power after the turn before shifting to 2nd gear. They looked at the ABS sensors and saw that the brake switch was all weird. We replaced the switch and then the vehicle drove exactly the same. He said the brake switch on the data was showing a weird pattern of inconsistent on/off so I said I'd put in LED bulbs. We tried just disconnecting them and the car drove perfect.... After all the work hahaha. At least hopefully the car won't need any major services for now.
10-10-2022, 01:04 AM
This thread did not disappoint. You did so much, and I'm so glad that you had the confidence in your work to keep looking to the next thing. And what's more, you actually weren't wrong! I'm so curious as to how this fault was found. The problem was with hard acceleration, but the brake system interfered because it was wired to interact with ignition.. how the heck would that be isolated when brake activation wasn't involved with triggering the fault?