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Q: Error Codes P011, P021, P300 on 2004 Infiniti G35

Says its the Crankshaft Position Sensor Failure on Bank 1 and Bank 2. I ordered new sensors to put in tomorrow. Any one else know what might have caused these error codes? I washed the car earlier in the day and thought maybe there was a short? Only thing I notice about the car is when I'm idling it wants to die. Also, I noticed the Idle is very very low, a couple hundred RPMs when its warmed up.....Any ideas? Could the Crankshaft sensors do all of this?
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Usually the codes have 4 digits i.e. P0300, etc. Are the codes P0011, P0021 and P0300? If they are then the P0011 and P0021 are Camshaft Sensor codes, ( not Crankshaft Sensor Codes ) and occur 1 for each bank. How many miles are on your vehicle? Did it occur immediately after the carwash? Were there no problems before that?
Now that you have replaced the camshaft sensors and the vehicle still idles really low I have a simple test. Try turning your steering wheel 180 degrees and see if the engine idle increases. If it does not, then your idle air control motor is weak. Also turn on and off your A/c system and see if the idle increases or not. With the A/C on, the idle should pick up. If not, then the idle air control motor is suspect. You may have an electronic throttle body which is a more complex idle air control motor.
Dear G35 owner,

This means that the idle air control motor is responding, at least to some degree. If this problem came about over time, it could be that your throttle body is very carboned up and not allowing the minimum air rate. This can cause the vehicle to idle so slow that the engine will set misfire codes (P0300) and even other codes such as cam sensor codes ( the computer needs to see a certain rpm baseline to read the cam sensors and control the timing ).
If you do not know how to check the throttle body for carbon restriction, then take the vehicle to a qualified pro.
Does the vehicle idle well when it is really cold, like at first start up in the morning?
If your car idles smoothly at 1300 when cold and then slows down to 200-300 but stays smooth then that's useful information. The only problem with 3-stage fuel system cleaning is that it doesn't really clean out the minimum air rate carbon around the throttle blade, it mainly cleans the intake manifold, the injectors and intake valve stems which sound decently clean if your car idles smoothly when cold then it sounds like 1 stage of your idle control is responding. It sounds like your cold idle valve is working which is usually a wax-pellet-temperature responding valve and then the computer idle takes over. ( many cars have 2 valves ) I just looked online at your idle system and it has a drive-by-wire system with a throttle position sensor in the accelerator pedal and 1-2 on the throttle body module so it is pretty high tech. At this point I-we need some data on your fuel system readings, i.e. TPS data, Long Term & Short Term Fuel Trim to see if your Mass Air Flow Sensor and Oxygen Sensors are reading correctly in relation to your injector pulsewidth. I need to see your desired idle vs real idle data we know that the idle is 200-300 but does your computer know this? I need to see you idle air command percentages in drive i.e. it should be in the range of 20% -30%. If it is, say 50-70% then we know that your computer is trying to raise the idle and either the idle air control is not responding or there is something keeping the engine from responding like a lean condition, such as an vacuum leak or an under reporting Mass Air Flow Sensor. If you can find a tech who has a sequentially logical approach( like we are trying to do ) to these type of problems that would probably be the next best step. You already have some good info to give him or her. If the person does not know what we are discussing here, then find someone else. Your car is too expensive to just 'throw' parts at ( as you have learned ).
I ngot the camshaft sensors replaced, but I don't think that was the problem, so I'm out 150 bucks. ouch. My car seems to run fine, the only problem I have now is my idle is too low, and sometimes it acts like it wasnts to quit, but it doesn't. With everything being controlled by the computer, I have no way to know what it is until I get a mechanic to hook up to it and run a diagnostic. I think my options are limited.
Okay, I performed the test. When I turned the wheel all the way left or right, the idle stays the same, and when I released the wheel, it briefly spiked, but then goes back down. When I turned the a/c on, it stays the same, and when I turn it back off, it spikes briefly. What does this mean?
Yes, when I first start the car, it idles at roughly 1300 rpm. It slowly comes down from there, and eventually stops at 200-300rpm when its warm. The car does have 65,000 miles on it. Would you suggest the 3-stage fuel cleaning offered by Valvoline? This is a link to their service:
i know this is a lil late but in case anyone else has this prob. just had the same issue w/ my G. Check your oil. Mine was about a half quart low on oil and was freezing up the actuators..your description sounds almost identical to mine. I added the half quart cleared the codes and have been OK since
most likely u got water around youre coil boots and plugs unbolt coils and remove blow water out of plug holes then remove plugsdry all components with breakclean reinstall replace plugs if necessary.
I got the P0011 code and nothing else. Camshaft sensors were fine. Mechanic traced it to low oil because of a blown paper seal in the front of the engine. $1500 repair. This is a COMMON problem with the 2003 2004 G35's, which were the only ones that used the paper seals (the inifniti engineers fixed their stupid design in later models and installed a rubber/steel belted seal at the factory).

The ECU blows the P0011 code because the oil pressure is slightly low as a result of the blown gasket. You can clear the code, add oil, and you might be good for a while--but it will come back. Only fix is to take apart the whole front of the engine and replace the seal.
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