this is when things turned interesting. the vehicle began to run extremely rough and the foul smell of misfire emitted from the exhaust. i had a reduced engine power notice on the screen in the cluster.
along with the stabilatrak service light ( will come on with reduced engine power, in diagnosing fix the drivability issue first )
upon the arrival of the vehicle in my work area i measured incoming fuel pressure from the fuel pump to verify i had proper fuel pressure. i did this before scanning codes which was me jumping the gun but verifying a factor. it was with in 45 psi to 50 psi plenty of pressure to feed the high pressure pump.
now we get to the fun stuff i scanned the DTC (diagnostic trouble code) to be a P2135 pedal position sensor a and sensor b not plausible. if you look on the internet and identifix it will lead you to just replacing the throttle body , shot gunning the part.
i chose to verify some thing first the pedal position sensors and throttle position sensors should be showing the same voltage to the pcm in your live data. the voltage should range from 1.0v to 4.0 volt
with the vehicle in key on engine off i witnessed the pedal at 1.2 volts and the throttle body at 1.6 volts a reasonable difference in % of throttle desired
so i pulled off the air ducting to expose the throttle body ( a little dirty on the throttle plate)
had a helper press the Accelerator pedal with the vehicle with the engine off and the throttle functioned normally. so the position sensor part of the throttle body (not entirely serviceable) could be bad but with the throttle assembly working i though that with the minor difference and the throttle assembly being dirty it could just use a cleaning.
removing the throttle body was pretty easy after removing the ducting its just the connector that need to be removed and the four 10mm head bolts on the body itself. there is a seal on it that can be reused if not damaged.
i used throttle assembly cleaner and a nylon bristle brush to scrub the housing plate and tunnel thoroughly.
with it cleaned to my satisfaction i reassembled the throttle body and cleared DTC's now with the vehicle running the positions match and ran a p2135 verify test (option with my scan tool to do a specific code test) and no problems being found test drove through a warm up cycle and cool down with no issues or check engine light
usually throttle cleanings don't have that much to do with major drivability issues but in this case it did and i saved he customer about 400 dollars
this isn't always the case but it was a worth while endeavor
With the vehicle running fine i changed the oil to get rid of any fuel wash the vehicle might of had as there was a fuel smell in the oil
CONFIRMED FIX: p2135 performed throttle body cleaning and reassembled
Thanks for the info. I was curious if you disconnected the battery before removing the throttle body? I don't know much about the Regal 2.4l Ecotec engine.
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteI have this exact same problem on this exact same car. Was trying to clean the pedal position sensor. Haven't tried cleaning the throttle body yet. But this article was useful.
ReplyDeleteIt proved to be Very helpful to me and I am sure to all the commentators here! kart
ReplyDeleteGot this exact problem on my '11 Regal 2.4L yesterday.
ReplyDeleteWondering if I can clean or replace throttle body myself or does a shop (or dealer) need to recalibrate or reprogram?
Thanks for this article.
UPDATE: Replaced throttle body myself. I disconnected the negative terminal of the battery first. After reassembly, I ran through a recalibration procedure from behind the wheel (3 min. idle-1 min. off, 3 min. idle-1 min. off). Recalibrated features that the instrument panel asked me to do. Ran a diagnostic code check: no P2135 code. Cleared all codes. Ran car on highway over 44 mph, accelerated and decelerated.
ReplyDeleteAfter one week of driving, all is well.
I appreciate everything you have added to my knowledge base.Admiring the time and effort you put into your blog and detailed information you offer.Thanks. reduced engine power
ReplyDeleteI am just over 300 miles from home. Is there something that can be done to help me get home?
ReplyDeleteI have a 2011 Regal 2.0T and she tur ns over but wont start. happened after I put circle K 89 gas in a couple of hours after it hesitated like it was going to shut off for like a minute and stopped my car has never done or acted like that before like a week later after we filled her up with gas somewhere else on my bday she was fine most of the day until we got in to go get a coffee and head home she spidered again this time the check engine light came on and it said reduced power pulled over turned the car off and she wouldn't turn back on. We have changed the intake & exhaust selinoid, coils & spark plugs, MAF sensor, fuel pressure sensor and still wouldn't completely turn over so we changed the MAP sensor & Air intake temp senor she was turning over but har battery died then we charged the battery and now we're back at the same place turns over but wont start. She codded P228D 1st then P2227-2228 & P0113 before we changed sensors & still has same codes. We can't find any repair video or info on our car anywhere and that our fuel pump access is under our backseat passenger side and it's not their, so frustrating and stressful
ReplyDelete