96 / Code P1508
Thread Starter
Race Director
Joined: Feb 2001
Posts: 13,910
Likes: 101
From: Manassas VA
NoVa Events Coordinator
St. Jude Donor '14
Re: 96 / Code P1508 (Bluewasp)
What would cause a P1508??
P1508
Idle Speed Control Open Circuit Fault
Code trips with the AC on.. Crappy idle if I start the car with the AC on... Anyone know how to fix the problem?
http://www.spanishtrailrovers.com/Te...can_codes.html
--------------------
P1508
Idle Air Control (IAC) System Low RPM
http://www.batauto.com/GM/96_575OBD2.html
[Modified by Bluewasp, 10:24 PM 8/16/2002]
P1508
Idle Speed Control Open Circuit Fault
Code trips with the AC on.. Crappy idle if I start the car with the AC on... Anyone know how to fix the problem?
http://www.spanishtrailrovers.com/Te...can_codes.html
--------------------
P1508
Idle Air Control (IAC) System Low RPM
http://www.batauto.com/GM/96_575OBD2.html
[Modified by Bluewasp, 10:24 PM 8/16/2002]
Drifting
Joined: Nov 1999
Posts: 1,801
Likes: 2
From: St. Paul MN
Re: 96 / Code P1508 (Bluewasp)
Did you check your Idle Air Control counts? Maybe you need to adjust your throttle body to get the iac counts into the correct range. Seems to me about 50 is good for idle with the car warmed up. Maybe I'm off a little on that and others can correct me there.
Thread Starter
Race Director
Joined: Feb 2001
Posts: 13,910
Likes: 101
From: Manassas VA
NoVa Events Coordinator
St. Jude Donor '14
Re: 96 / Code P1508 (Bob86ZZ4)
Did you check your Idle Air Control counts? Maybe you need to adjust your throttle body to get the iac counts into the correct range. Seems to me about 50 is good for idle with the car warmed up. Maybe I'm off a little on that and others can correct me there.
Le Mans Master
Joined: Aug 1999
Posts: 7,338
Likes: 137
From: WilkesBarre PA
Re: 96 / Code P1508 (Bluewasp)
I would say the AIC is either full of crud and just needs to be removed and cleaned, or it is bad. The a/c is putting a load on the motor and the AIC is not adjusting the idle for it.
Thread Starter
Race Director
Joined: Feb 2001
Posts: 13,910
Likes: 101
From: Manassas VA
NoVa Events Coordinator
St. Jude Donor '14
Re: 96 / Code P1508 (RichS)
I would say the AIC is either full of crud and just needs to be removed and cleaned, or it is bad. The a/c is putting a load on the motor and the AIC is not adjusting the idle for it.
Le Mans Master
Joined: Aug 1999
Posts: 7,338
Likes: 137
From: WilkesBarre PA
Re: 96 / Code P1508 (Bluewasp)
It's mounted on the Throttle Body under the TPS. They sell a Throttle body cleaner at the parts store to clean them.
[Modified by RichS, 8:05 AM 8/18/2002]
[Modified by RichS, 8:05 AM 8/18/2002]
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Safety Car
Joined: Feb 2002
Posts: 4,212
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From: Sun City West Az
Re: 96 / Code P1508 (RichS)
To get the counts (tells how far the pintel has moved off its seat to allow more air to by pass), you need to hook up a scanner on the ADL which is under the drivers dash on the right side. Autoxray ( @Kragens -$150.) makes a decent one along with some others. Money well spent. :yesnod:
Drifting
Joined: Nov 1999
Posts: 1,801
Likes: 2
From: St. Paul MN
Re: 96 / Code P1508 (ittlfly)
Okay, first it is an IAC (idle air control). It screws into the side of the throttle body and has a electrical plug connected to it. It takes a very large wrench to unscrew it. To check what the counts are you need to hook up a scan tool to the ALDL (assembly line diagnostic link) which is the plug under the dash above the gas pedal. I think some of the late C4's have them maybe behind the center panel on the dash but I'm not sure about them, sorry. And you do need to hook up a scan tool to watch what the IAC counts are. Any good service station will hook it up and show you and probably not charge you if you are a regular customer, or the mechanic likes Vettes and wants to sit in yours for a minute. Make sure to use throttle body cleaner and not carb cleaner if you decide to clean it. I would check what it is at before cleaning it tho.
Drifting
Joined: Nov 1999
Posts: 1,801
Likes: 2
From: St. Paul MN
Re: 96 / Code P1508 (Bob86ZZ4)
I just noticed you have a '96. For that the $150 scan tool won't work. I think the '96's switched over to OBD II didn't they? That's On Board Diagnostics Second Generation. And a simple OBD II code reader will not show you what the IAC counts are. It looks like you had access to a code reader to come up with the original code. So, get a scan tool hooked up and watch it. Good Luck.
Thread Starter
Race Director
Joined: Feb 2001
Posts: 13,910
Likes: 101
From: Manassas VA
NoVa Events Coordinator
St. Jude Donor '14
Re: 96 / Code P1508 (Bob86ZZ4)
Okay, first it is an IAC (idle air control). It screws into the side of the throttle body and has a electrical plug connected to it. It takes a very large wrench to unscrew it. To check what the counts are you need to hook up a scan tool to the ALDL (assembly line diagnostic link) which is the plug under the dash above the gas pedal. I think some of the late C4's have them maybe behind the center panel on the dash but I'm not sure about them, sorry. And you do need to hook up a scan tool to watch what the IAC counts are. Any good service station will hook it up and show you and probably not charge you if you are a regular customer, or the mechanic likes Vettes and wants to sit in yours for a minute. Make sure to use throttle body cleaner and not carb cleaner if you decide to clean it. I would check what it is at before cleaning it tho.
