Q: P0505 code Idle Air Control for bmw 540i

asked by on October 19, 2017

To start this code has been with me since I bought the car. The car would turn off when coming to a stop light/sign very randomly and without warning. First time scanned came back with a TPS malfunction code. Replaced it because it was bad BUT still kept having same issue. Then my mechanic said it could be the IACV itself, replaced it, still kept turning off randomly. Lastly, did a smoke test with 10psi or pressure, found a vacuum leak, sealed it up with hose clamps around the piping that had no clamps on it. Now since then, been a few days, car has NOT turned off randomly at all like before BUT code keeps showing up after about 40minutes. What do you think the issue is? And will cleaning the Throttle body think will fix it? What are your thoughts. Only code I get. Car runs so smooth but that code pops up. No erratic idle low or high, usually it’s idling a little above the tick mark on the speedometer.

My car has 210000 miles.
My car has a manual transmission.

The TPS can have between 5 and 10 different codes and all will be caused by different failures of the TPS, Throttle body, wiring or computer issues and you will need to supply the code you get to help you isolate the cause. If you have the codes pinpoint tests done by a mechanic like one from YourMechanic then it can be isolated to actual cause of problem and not just putting parts on in hopes of fixing the light coming on.

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