6

Please see the video of the problem: https://www.youtube.com/watch?v=FHJPoHPamjg&feature=em-upload_owner

I'm very stumped to why this is like this all of a sudden Ford Focus MK2.5 Strange Misfire Engine Light, ESP Light, Battery Light Turn up sound to max to hear the misfire ODB readout code P0336 - “A” circuit of the crankshaft position sensor has a range/performance error. Self diagnostic read out: E196 - Invalid data for engine RP

Battery seems to operate at 14.1v when running and 12v not running

Misfires and other stuff ( Speedometer stops working) seem to happen after 5k revs. Not exclusive to that though as car will sometime shut off when driving very slowly

In the video you can see the speed counter dies first and then the battery and other lights come on temporarily but ESP stays on for some reason. Engine continues to drive(struggles)

At 23 seconds in the car nearly completely stops but my foot was completely down and it kept it going only just

Not sure how to fix, if an exhaust clip would help you listen to the engine then I will post if you request

  • Can you confirm it's actually misfiring in OBD2 Mode 6? The way the lights flash makes it seem like a cluster issue. Problems with a crank sensor will also cause misfires you may want to scope the sensor signal return wire. Make sure it's aligned properly etc... – Ben Jun 12 '16 at 20:26
  • Hi Ben, I checked the mode $06 and it seems to not have any missfire component sensors? See below the print out – Jeremy Jun 12 '16 at 22:37
  • See the table here: pastebin.com/86sFZdMQ The for scan read out also: pastebin.com/JFi7rqFy – Jeremy Jun 12 '16 at 22:37
  • Whatever software you're using may not be looking for the tests. Either way you need to take a look at that crank sensor. If you can view live look for the signal to drop out when you do your testing. – Ben Jun 12 '16 at 22:43
  • Problem is I don't think I can live check it as the doesn't seem to be a PID for it. As the DTC reports that the sensor Signal is Above Maximum Threshold would it be as simple was replacing the sensor – Jeremy Jun 12 '16 at 22:46
4

My first questions for you? Isn't that a new car, still under factory warranty? What did the dealership tell you? (What year is the car? what is the mileage?)

If not, that sure looks like a wiring issue to me, based on that tachometer dropout. Loose ground? Intermittent short or disconnect to the crank (and / or cam) position sensor? Note the crank (and / or camshaft) position sensors are way easy to troubleshoot. You take a screwdriver and move it near the sensor back and forth and read ohm / resistance at the input to the engine control computer. Its quite easy to see when something is amiss. My guess is there is a loose wire somewhere, that is impacted by drive cycle (and G force...)

Its possible you have a bad sensor, but those things are crazy reliable. There really isn't much to go wrong with them.

I sure start with the wire directly to the position sensor, but it would also be a good thing to check all grounds in the system, particularly those that feed the instrument cluster.

Another defect observed (in my experience) is a "pinout". A pinout happens when the electrical pin (or socket) isn't fully seated in the plastic hardshell connector and only makes intermittent connection. A plastic hardshell connection is used to join wire harness pieces together, or to join a harness to sender or other electrical unit. Remember each of those is wires is hand placed when the wiring harness is being built, and although extremely rare, this sometimes can happen.

You'll need a wiring diagram for the vehicle. Examine every connection, open it, use a flashlight and examine each and every pin and socket contained within. You will be able to see a pin or socket not fully seated.

Next you'll want to use that wiring diagram to examine each and every ground in the car. I suspect there are 8 or 10 of them on this car. Pay particular attention to the two ground screws for the instrument panel inside the car. I'm guessing somewhere on both left and right A Pillar sheet metal, just inside the lower door hinge area. Ensure the ground screw is tight and that nothing seems amiss.

  • Will check today thanks. Also i've owned this car for a year and theres no warranty. Never displayed any behavior like this ever either. 2009 44k mileage – Jeremy Jun 13 '16 at 9:35
  • Turns out it's a loose craftshank position sensor somehow the plate securing it has broken off so its hanging loose. Going to have the gearbox removed for a new one to be fitted apparently – Jeremy Jun 13 '16 at 12:34

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.