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Discussion Starter #1
So lately I've been having some issues with my 2003 Deville. A couple months ago it would continually stall out and had extremely low rpm's. It would also do the opposite and have rpm's around 1000 when idling. I cleaned out the throttle body, cleaned the IAC valve, and filled up my tank and it seemed to go away. After about a month it's gotten really bad, and yesterday I became afraid to drive it. I start it up and it will sit at about 1500 rpm, when I touch the gas it will rev up to 2400 and sit there for awhile, and so I cleaned the entire TB again. No change. I believe it could be either my IAC valve, or Plenum leaking. I disconnected my IAC valve and started again and noticed no difference which leads me to believe that it is broken. I'm taking my girlfriend to Disney World in 2 days, would absolutely love some help.

Engine Codes: (I know my TCC solenoid is broken, has been for the last 50k miles)

p0106
p0507
p0741
p1860

Thanks in advance for any advice.
 

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2001 Seville STS, 1990 Seville (RIP), 1972 Sedan Deville
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26,323 Posts
Codes are meaningless without their definitions. There's a link to code definitions within the sticky thread on how to pull DTCs.
 

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Discussion Starter #3
Code definitions for convenience:
p0106 - Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance Problem
p0507 - Idle Air Control (IAC) System RPM Higher Than Expected
p0741 - Torque Converter Clutch Circuit Performance or Stuck Off
p1860 - TCC PWM Solenoid Circuit Electrical

Sorry for not including in the original post.
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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The TCC and solenoid codes can only be cleared/repaired by a complete transmission removal, internal output shaft (converter) seal repair and converter overhaul. P 1860 is the TCC fluid control solenoid - P 0741 is the converter viscous clutch fluid application and control failure. If you see only a P 1860 that can be repaired using the microsurgery technique posted in the videos in Tech Tips.

You can drive the car with one or both codes but it will not pass emissions when the time comes. Otherwise, you lose about 2 mpg due to the slight increase in converter slip. Your car is perfectly happy on 87 octane 24/7/365, and if it's a Deville or DHS with the 3.11:1 final drive you'll drop from maybe 27-29 mpg open highway long term to 26-27.

Remove the IAC (carefully) and clean the shaft, pintle and TB bore with TB cleaner spray and lint free rags. Make sure the black "top hat" and shaft are fully screwed into the IAC body - fingers, not pliers. Might as well spray the electrical plug/contacts, too.

When you're done, assemble everything, make double damn sure the air intake ducting is leak-free, and turn the key ON for 15 seconds, off for 30, start and let the engine complete the fast idle sequence - 1200 for 10-20 seconds, 900 for a while longer, then to 650 idle.

Remember to keep the engine oil at the halfway point on the dipstick hashmark - not all the way to the top. Run your tires at 32 psi, cold, for a slight gas mileage savings. Never check/bleed tires warm or hot.
 

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Discussion Starter #7
Thanks for the responses guys I really appreciate it. I took out the iac valve and cleaned it but it didn't work. I bought a cheapo new one on eBay for $15 just because the ac delco one was $160 and now it works perfect. Honestly better than I remember it running in a long time
 
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