Nissan IAC P0505 Harness ECM Probing Diagnostic idle surge
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- čas přidán 7. 09. 2024
- ScannerDanner video that I followed you must watch:
• How to test an Idle Ai...
I am going to change the IAC chip in the ECM soon, there are also vacuum leaks at the plastic intake tube at the Throttle plate, and also a leak somewhere under the intake manifold.
2001 Nissan pathfinder 3.5L v6 with p0505 code warm Idle surge cannot relearn
SES light will not flash on relearn process and dealer level scan tool will not complete auto relearn process.
Great video. I always like to get the perspective of a few different ppl for tasks I haven't tackled before. I wish I would've seen this earlier in the week because I had my dash taken out trying to gain access to the ECM.
Oh boy, sorry to hear that!
ScannerDanner video that I followed you must watch:
czcams.com/video/Wt_zTJWbDzs/video.html
IAC chip was replaced and all vacuum leaks were fixed. Idle has returned to normal but there seems to be something else going on with the ecm.
2001 Nissan pathfinder 3.5L v6 with p0505 code
SES light will not flash on relearn process and dealer level scan tool will not complete auto relearn process.
This vehicle already had the IAC replaced, if your voltage reads steady 0 on one of your wires you could have a bad iac motor.
Just curious ever figure it out ? Sounds similar to mine . Iacv went and took out chip . Replaced both . Now idle starts high then after some time drops to 300 and struggles to stay alive . I couldn't get engine light to blink on relearn and dealer got it to complete but then the idle dropped back down. When I tested my 4 outter pins on the iacv plug. They all started at 0.46v and then cycled up to 11.50 when I turned the key on , but I noticed pin 1 and 3 held 11.5 volts while pins 4 and 6 dropped down to 0.022 . Do you know when the key is on if the pins are supposed to hold 12v or cycle then drop to 0v? Any help would be appreciated. Thanks
First you said the 2 center wires were ground, then 3½ minutes in, you said the middle wires were power supplies??
I think I corrected that with an annotation on the screen, but check out the scanner Danner video link in the description. It's better than mine
did you ever fix it? i have an 02 pathy, ive replaced the IACV, replaced 3 o2 sensors, and a fuel filter. My pathy is still surging between 2000 and 3000 rpm on cold starts. The only way for me to get it to run normal is if i let the engine warm up and turn it off and on 30 times to get it to idle at 850 RPM....
I replaced the iac chip in the ecu. Now the engine will idle cold and hot. The only issue it still has is that if you're slowly accelerating in first gear, between 1000-1500rpm it will jerk like crazy like before. I'm assuming something is still wrong with the ecm. I retested the voltage and the problem changed location. I also never did the pumping the pedal procedure after this the cel never flashes. Before I changed the chip the engine would run high idle and then surge when it hit the ecm required temp to change strategy.
@@WCGwkf Hmm, for your problem, I could only assume with my knowledge that your throttle position sensor might be off by a few volts because the other grey connector connected to the TPS is the transmission gearing switch?? that's not the right name for it but it has something to do with the transmission. My situation is, I have a sensor 1 o2 sensor flat lining on the graph warm or cold engine and its brand new, can't figure out why... and I have a bad cat on bank 2, I have a brand new OEM IACV, cleaned throttle body and new TB gasket, I bought a KAG OBDII to USB cable to connect my laptop to the ECU to perform Idle relearn with an application (NDS II) that emulates the CONSULT II scanner Nissan has at dealerships that cost $2000, but of course the idle relearn doesn't work at all lol (with or without scan tool), new fuel filter, fresh coolant flush, fresh engine oil, brake fluid flush, TPS sensor calibrated using voltameter, and yet after 3 months of working on this thing any time I have the idle surge persists... I'm going to see if I can do the test you have shown on the wiring harness for the IACV, never thought of that. I also need to pull my ECU out and check if the chip is burned, I sure hope not, but I know here in SC they have a place that rebuilds ECU's for around $200. Haha this pathfinder is embarrassing starting it up early morning for work XD
Did you fix it? I also am having the same type of issues with my 01’ Pathfinder. First I replaced the #4 ignition coil because of the trouble code I was getting and the misfire. I had to remove the IACV to reach the bolts for the ignition coil. It ran great for a week, then I had idle surges to 1500 rpm at idle and fluctuations. Replaced the IACV and cleaned the TB with new gasket. Tried the relearn procedure but it didn’t work. And now my idle doesn’t surge. It just slowly decreases and kills the engine. I’m going to check the ecm and see if the chip is fried next. Any insight would be greatly appreciated. This is one annoying problem!
@@SupraKing12365 if you have a local shop that will rebuild for $200 it's probably worth it. This vehicle wasn't my daily/only vehicle so I didn't fear diving in. Really the hardest part was getting all of the solder off the pins to get it free. You also have to make sure you don't have some gross vacuum leaks, I have a video on that too. Main culprit is the breather tube under the intake manifold that goes between both valve covers. If you have a new iacv, your harness isn't fried, the iac fuse in the engine bay isn't bad, and you don't have vacuum leaks it's likely the chip. Even if it doesn't appear burned it can still have an internal short. The test in the video should confirm, but also watch the scanner Danner one. My video is more of an example of what he showed. It's also possible that if your chip is fried / harness is messed up you can fry your iac motor right away. The whole problem with this system is coolant running through the iac. Super dumb design.
@@WCGwkf yeah, ill have to take a week off of work to send my ECU up to the repair place, its $250 and its definitely my ECU. Everytime i drive my car i smell it burning... but its still running somehow, dont know how long that will last though. And the fact that it disrupts the A/F ratio it has ruined my cats too. And the ECU has destroyed the brand new IACV i just put in there 4 weeks ago. I wonder if i can just put a custom ECU in there that wont burn out ever like they are supposed to do.