P0505 DTC Code
#1
P0505 DTC Code
Howdy,
Got a 2001, 5.2 that is getting this code. My truck is idling high, but only about 100-200 rpm higher than it should be (750-850 rpm). I've replaced the iac, cleaned the ports and reset the pcm. If it is a vacuum leak, im guessing its really small, as I didnt detect any with carb cleaner. When I searched the forums the rpms in those cases are significantly higher. Just curious where I should look next. Thank you kindly in advance.
Got a 2001, 5.2 that is getting this code. My truck is idling high, but only about 100-200 rpm higher than it should be (750-850 rpm). I've replaced the iac, cleaned the ports and reset the pcm. If it is a vacuum leak, im guessing its really small, as I didnt detect any with carb cleaner. When I searched the forums the rpms in those cases are significantly higher. Just curious where I should look next. Thank you kindly in advance.
#3
#4
Thank y'all for the responses, I did a couple more diagnostic checks and I think I have at least a plan of attack.
First thing I did was put the truck in the On position and check for voltage from 2 of the 4 IAC ports. Which I had.
I then started the truck with the IAC unplugged, and it basically ran exactly the same as when it was plugged in.
I went and also checked voltage on the IAC ports and I was getting voltage from all 4 ports. It wouldn't stay on constantly, but I believe that is to be expected. This makes me think the PCM is working.
So I think my next step would be to replace the IAC (it's only a year old, but was one of those cheap Advance Auto Parts Driveworks IACs) and if that fails, then it'll probably need a new PCM. Does this seem like a logical approach?
Thank you all for the feedback!
First thing I did was put the truck in the On position and check for voltage from 2 of the 4 IAC ports. Which I had.
I then started the truck with the IAC unplugged, and it basically ran exactly the same as when it was plugged in.
I went and also checked voltage on the IAC ports and I was getting voltage from all 4 ports. It wouldn't stay on constantly, but I believe that is to be expected. This makes me think the PCM is working.
So I think my next step would be to replace the IAC (it's only a year old, but was one of those cheap Advance Auto Parts Driveworks IACs) and if that fails, then it'll probably need a new PCM. Does this seem like a logical approach?
Thank you all for the feedback!
#6
Thanks for the info.. I did replace the IAC this morning, and after resetting the PCM, the truck started fine, when it warmed up it was at 650 RPM. Shut the truck off, went to turn it back on, dies immediately. Seems like it might be a defective IAC, as this was the symptom when the original IAC failed. Does that seem like a reasonable conclusion? Was a Mopar part, but got it off eBay, so might be a cheap knockoff.
#7
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#8
So, just an update. (Sorry for the slowness of it.)
The DTC is still there. I cleared it, drove it 3000 miles from Texas to Wisconsin and had no problems. I went and checked continuity and that was solid, with fairly low resistance. When I unplug the IAC and clear the DTC, the P0505 comes back right away. I'm fairly certain at this point that the PCM is the issue. I was just wondering if there was any last checks I should do to see if it could be something other than the PCM?
The DTC is still there. I cleared it, drove it 3000 miles from Texas to Wisconsin and had no problems. I went and checked continuity and that was solid, with fairly low resistance. When I unplug the IAC and clear the DTC, the P0505 comes back right away. I'm fairly certain at this point that the PCM is the issue. I was just wondering if there was any last checks I should do to see if it could be something other than the PCM?
#9
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