Jump to content
CaddyInfo Cadillac Forum

Idle relearn


Recommended Posts

Can someone pleas post a general procedure for the idle relearn.

I need it for my 97 SLS.

I just did intake, gaskets, cleaned TB, TB spacer, egr cleaning and gasket.

I tried disconnecting the battery and reconnecting, then starting the engine and holding it in drive for 5 minutes, didnt much help.

At idle in park it range from normal to 950-1000. Sometimes it is different when I shift back into park.

In gear stopped idle is about 825.

Sometimes it throws a P0507 code and goes into history

before I did all the work it was fine, but I think the TB cleaning changed it all.

thanks all in advance

GM FAN FOREVER

Nice, clean, luxury= fine automobile

Link to comment
Share on other sites


DTC P0507 Idle Speed High

This diagnostic test is used todetermine if the idle control system is maintaining the proper idle speed. TheIAC system controls idle speed by allowing a certain amount of air to bypassthe throttle body, the throttle plate is closed during idle, through the IACvalve. The PCM controlled IAC motor moves a pintle in and out of the IAC valve,thus varying the amount of air entering the intake manifold. By varying theamount of air intake, different idle speeds can be achieved. When the pintle isin, the valve is closed and low idle speeds result. When the pintle is out, thevalve is open and high idle speeds occur. If the actual engine idle speed ismore than the desired idle speed and all test conditions are met DTC P0507 willset.

This DTC, and a high idle, could be caused by a noisyPower Steering Pressure (PSP) switch or an intermittent open in the PSPcircuit. If a faulty PSP switch or a poor connection is suspected disconnectedthe switch and jumper the terminals together (harness side) if the idle returnsto normal or the DTC passes then the PSP switch or connection is faulty.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

There isn't really any relearn, the engine just settles down, look at the IAC, look to make sure the manual linkage allows the throttle plate to shut, make sure the linkage is on the STOP, look for vacuum leaks TB to intake (that would probably set lean code), make sure there is no leak at the IAC there is an O-ring on the IAC.

These are some of the things the manual states to look at. Did you remove and clean the IAC and its port?

Check IAC control circuits for opens shorts to ground and shorts to voltage

Visually/physically inspect for thefollowing conditions:

  • Throttle body tampering (adjustment screw).
  • Restricted air intake system. Check for a possible collapsed air intake duct, restricted air filter, or foreign objects blocking the air intake system.
  • Throttle body. Check for objects blocking the IAC passage or throttle bore, excessive deposits in the IAC passage and on the pintle, and excessive deposits in the throttle bore and on the throttle plate.
  • Vacuum Leaks

Check for poor terminal contact at the IAC harness connector

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

Ok I have removed the IAC and verified it is free. reinstalled. reset battery, still seems a little higher than normal but no light. Maybe it just takes time to recognize the proper idle

GM FAN FOREVER

Nice, clean, luxury= fine automobile

Link to comment
Share on other sites

Take it for a ride, it will adjust assuming that the IAC is good. How was the IAC port? Was the IAC or Port dirty or caked up with carbon?

Did you replace the oring/seal between the throttle body and the intake? (again, if it leaks there, you will set a lean code for both banks)

Keep in mind that you cleaned the entire intake, its breathing better, asl long as you dont have any leaks (that would set codes), you should be fine. I believe that a relearn requires a short trip, of stop and go, and it will adjust

It should settle down, let us know

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

Take it for a ride, it will adjust assuming that the IAC is good. How was the IAC port? Was the IAC or Port dirty or caked up with carbon?

Did you replace the oring/seal between the throttle body and the intake? (again, if it leaks there, you will set a lean code for both banks)

Keep in mind that you cleaned the entire intake, its breathing better, asl long as you dont have any leaks (that would set codes), you should be fine. I believe that a relearn requires a short trip, of stop and go, and it will adjust

It should settle down, let us know

I replaced all gaskets pertaining to the intake including TB spacer gasket, TB gasket, MAF gasket. I hear no leaks at all. and thank god no whistle.

The IAC and port were clean. looks like the IAC may have been replaced at one time.

Sometimes it idles fine, and sometimes it is slightly elevated. It is almost like it is learning. And I havent seen the light since I disconnected the battery

GM FAN FOREVER

Nice, clean, luxury= fine automobile

Link to comment
Share on other sites

How good did you clean the throttle plate?, did you get the edges and the throat?,

My guess is that when you had the throttle body off, when you saw the backside you were shocked at how dirty it was...

So you don't think the manual linkage is binding or the throttle plate hanging open at all?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

I was not shocked honestly, as when I did my 96 Deville 2 years ago I was shocked. But I have to say I was shocked with the egr pipe buildup in the spacer plate. I couldnt even get my pinkie in the port.

Now I am nearly certain that the throttle plate is not sticking. I thoroughly cleaned it while it was removed, both front and back. Before it was sticking closed a little.

I worked the throttle body well before I reinstalled it and retested once the cables were installed. Also I used only Throttle body cleaner to clean it

GM FAN FOREVER

Nice, clean, luxury= fine automobile

Link to comment
Share on other sites

Are you sure you plugged in all the electrical connectors near the throttle body?

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

Link to comment
Share on other sites

All vacuum hoses connected?

If you consider that your over pressurization valve was sucking air, the IAC probably compensated by closing. On restart if anything your engine should have idled slower than normal until it compensated but yours is idling too fast. odd

In the throttle is closed the IAC allows air to enter to stabilize the idle. If the PCM senses the idle is too fast, the IAC would close to limit air. If this does not stabilize and if you are sure that you have torqued down the intake and there are no vacuum leaks (again lean codes or misfires would set), I would swap in a known good IAC to see if it makes a difference. Also check the IAC port again to see if its blocked or has carbon on the seat.

Very odd, all of the work I did on my 96, I never experienced this

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

lol I havent really had to touch anything on my 96 to have anything happen. Seriously it just always goes. Shhh I never said that lol.

I may try another IAC but it seems to be starting to idle better

GM FAN FOREVER

Nice, clean, luxury= fine automobile

Link to comment
Share on other sites

well it seems disconnecting the battery did the trick. 130 miles and no light, no elevated idle. problem solved

GM FAN FOREVER

Nice, clean, luxury= fine automobile

Link to comment
Share on other sites

well it seems disconnecting the battery did the trick. 130 miles and no light, no elevated idle. problem solved

Terrific, glad to hear it

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

  • 2 weeks later...

Update. 6/30/11.

problem stille perstists. I find that when I start it that it seems ok but when I drive it then put it in park and let it idle for about 1 minute it is idling high(around 1100rpm) and MIL is on throwing the P0507 code.

So tonight I monitored the idle and IAC parameters and found that the actual idle was not even close to the desired idle. (example, desired idle in park is 625, actual idle in park is 1100 rpm).

I then went to manually control the IAC and noted thatthe IAC was controllable over 1100 RPM but even set manually to 400RPM the idle would not drop under 1050RPM, If I raised the idle it would go up to the max and down to 1100 but no lower.

So this is what I am hoping, It is possible in cleaning the Throttle body maybe some cleaner or debris got into the IAC and it is not functioning properly.

If it is not the IAC I am really stuck on this one. I have no clue what it could be.

Talked to dealer and they confirmed no idle relearn procedure for the 19977 MY, it is learned by driving characteristics , and have been told it can vary slightly with memory personalization by driver characteristics. Interesting. I would also assume by driving over 150 miles in varying conditions it should have learned the idle by now. So I am going to replace the IAC tomorrow and pray for good news

GM FAN FOREVER

Nice, clean, luxury= fine automobile

Link to comment
Share on other sites

When I have done work, I have never had issues getting the idle down, it happened automatically.

A vacuum leak would cause this but you are not getting lean codes

If you are sure the plate is closing, I would try a different IAC and see if that solves the problem.

However, that said there is this code DTC P1509 Idle Speed High - Idle Air Control (IAC) System Not Responding, that you are not getting

I found this regarding DTC P0507 Idle Speed High

This DTC, and a high idle, could be caused by a noisy Power Steering Pressure (PSP) switch or an intermittent open in the PSP circuit. If a faulty PSP switch or a poor connection is suspected disconnected the switch and jumper the terminals together (harness side) if the idle returns to normal or the DTC passes then the PSP switch or connection is faulty

Have you done this yet?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

I looked quickly in the GM SI manual, and they don't show a location. If you have a manual, its either located on the pump or rack, is my guess.

Do a search, maybe its been discussed. If you cant find it post, Ill check my 96 manual later, I have to run

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

have not tried that, can you tell me where the connector is for it?

Thanks

The connector is on the IAC which is the small round can looking device mounted on the throttle body.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

Link to comment
Share on other sites

sorry I think he is referring to the PSP sensor plug.

To update I replaced the IAC and it started well, It idled cold at 850 RPM. I manually controlled the IAC down to 440RPM and up. Then once I put it in gear then back to park the idle slowly went up to around 1000. I am going to drive it today and hope the idle learns itself. It sucks not having a actual tach readout on the cluster like my Deville

GM FAN FOREVER

Nice, clean, luxury= fine automobile

Link to comment
Share on other sites

Yes the PSP plug, I think Kevin knows where that is also

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

The power steering pressure switch plug (if that's what is meant by PSP) is on the rack and pinion unit.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

Link to comment
Share on other sites

Ok I drove it today and hoooked up my scantool at work and found this.

IAC position is 0 at anything 1100RPM and lower.

When I try to control the IAC manually with the scantool The IAC position increases to 3 at 1200 RPM and goes up from there but not down.

When the manual idle was set to 400 RPM the IAC position was 0 aand the idle was 1100 RPM.

I am extremely irritated on this I have to admit. I dont know if it is intake related, electrical, no clue. I hear nothing out of the ordinary other than the elevated idle.

I am curious to know if the PSP sensor is faulty will it control the IAC position or raise the idle by something else.the scantool temp readout seems normal.

I am also curious if it could be the CTS coolant temp sensor. But

I have checked again and again and no other codes ever come up other than the P0507.

Does anyone knoww how to access the PSP sensor to allow for jumping the terminals and possibly replacing the sensor?

Thanks all for all the help. I really cannot afford anymore right now. I may have to park it for now till next month

GM FAN FOREVER

Nice, clean, luxury= fine automobile

Link to comment
Share on other sites

I believe the PSP controls the idle via the IAC, but will do some research for you later

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...