TPS and ICM Question

[jndnaps]

1 hour ago, BodybyFisher said:

I am less concerned with that, then I am about the 4 bolts connecting the spacer to the intake, and the oring.

If we assume that the smoke test was legitimate, do you have the video, can you post it? 

I know you are doing a lot of work, it may make sense to pull the intake altogether with the TB installed, throw it on a table and inspect and work on it there, replace the oring, intake seals, look for cracks, etc. 

Let me know, Ill write a procedure and pull the procedure from the FSM

Yeah, I'm still sick and trying to do some things that I can handle. It's a mofo to be sick and out in 90* temps trying to do this stuff. LOL.. I still think if I gotta take the intake off I'm gonna do it on a car in the junkyard first. Just don't trust myself. LOL.. 

No, I don't have the video. 

[BodybyFisher]

Nah, you will be fine.  We will help.

I hear you about the temps, my 6'6" 38 yo son is in Boca and complained about the heat to me just yesterday.

[Logan]

You might find this link helpful.....sounds like the same problem. 

https://sparkys-answers.com/2009/10/1997-cadillac-deville-erratic-high-idle.htm

[jndnaps]

7 hours ago, Logan said:

You might find this link helpful.....sounds like the same problem. 

https://sparkys-answers.com/2009/10/1997-cadillac-deville-erratic-high-idle.htm

Yes, I saw this. But I sprayed that down with the starting fluid and it did nothing at all. Wouldn't it bog down when sprayed? I hit it pretty good with that stuff.. Although I did it on a cold motor, not when it was real hot.. 

[BodybyFisher]

I am not sure about what happened after 1996, but the 96 diagnostics system was VERY much like my 91 OBD1.   On my 96 and my 91, you were able to go into the diagnostics system and read the system data, much like the TECH 1 and TECH 2 do.   You 'see' the same data.   I have monitored fuel trims, O2 sensor data, etc.    I am pretty sure, that we can get your IAC count from the system much like a TECH2 would. 

If we can do that, @Logan noted above that IF the system is commanding the IAC to be closed or ZERO, you definitely have a lean condition.  (correct me if I understand this wrong Logan). 

The problem is this.....  I do not know the identifier of the IAC command data, to find it the data we need.  All you would need to do it get into the DATA subdirectory and go to the IAC data identifier.

Logan, do you have any info to identify the IAC command data info in the PCM?   There must be a list someplace like there was with the OBD1 system. 

Sometimes in the FSM, they will clearly identify the location for you to access with the TECH2 and that is the location you need to navigate to manually through the DIC. 

I need to go through the FSM closer to see if I can find the location identifier for the IAC.   I would also like to see your short and long term fuel trim data, that would show rich and lean conditions

[BodybyFisher]

What do you all think of this idea. 

My friend has a 98, what if I hook up my Tech 2 to his system, and navigate to the IAC command data and find the name of the identifier that way?

@Logan  What do you think about that?  I would get the identifiers for the IAC, fuel trims Long and Short term, throttle percentage, throttle position switch data, etc.

[jndnaps]

Spent 30 mins with brake cleaner trying to find anything and again nothing. The idle is so erratic that I can't really tell if I'm hitting the spot or not. What about testing to see if there is power going to the IAC and the TPS? This car's got me beat.  

[BodybyFisher]

These wires have me concerned.  

Let's check the IAC wires for continuity, short to ground and short to power. 

Pull the connector off, the plug should be marked A, B, C & D, if not use the colors from the schematic below.

Using your ohm meter check the continuity back to the PCM plug C1 again, pins 8, 9, 10 & 11 respectively.  Check the pins on both ends for corrosion.  If we can get you into the diagnostic data we may be able to see what is going on. 

We can not test voltages here, this is PWM, but we can test to make sure the wires are intact from the PCM to the IAC 

If there is a crack in the intake where you can't get to it you won't find it.  I still think you will need to remove the intake at some point.

[jndnaps]

OK, Guys, sorry I disappeared for a while, but I was mega sick. Feeling a lot better now, so I'm gonna get back at this a little. Now, let me just say that I noticed earlier today when I hit the gas a few times it felt like the gas pedal was stuck. When I cleaned that TB it was spotless when I was done. There was nothing anywhere around the "butterfly?" that it would stick to. That sucker was spotless. So next week I'm gonna check the cables.. I don't think the cruise control even works anymore, so can I leave that cable off, or does it need to be on?? 

The only current codes it has is still the IP2511 and IP2515.  See picture. Now if these are B codes, that kinda makes sense because the steering wheel controls don't work and the radio and A/C acts up like I'm messing with the steering wheel controls. 

B2511 -  Steering Wheel Controls Conv Key Stuck.. and  B2515 - Strg Whl Cont Illegal Resistance Value. This one (B2515) comes and goes between current and history. 

P2511 would be - ECM/PCM Power Relay Sense Circuit Intermittent and P2515 would be A/C Refrigerant Pressure Sensor "B" Circuit. 

I still have no clue how to read these correctly, but here is a pic of the code below. This is how it comes up on the on board computer. Also, I'm reading these codes through this web site.

https://obdii.pro/en/model/cadillac?fbclid=IwAR001wc2SGNAKyjSIzQ9IVX_EE3kyn8SQiSIE-ilNUyWqPdFVRBTNhXP3Cc
 

[BodybyFisher]

Ill come back later, lots to look into here. 

If your cable is hanging up that would explain a lot.    A lot to digest here

I will be back after dinner, I know its late.

Glad you are feeling better

I think the IP2511 is a B code

[BodybyFisher]

I edited the above message

[rockfangd]

Cruise cable not necessary to be hooked up.

One of your steering wheel control switches is either stuck or shorted.

See each one of them when pressed provides a different specific resistance value that is translated by the  computer and sent to the IPC (iirc) Then it is sent out to the module from there. This makes me wonder if you have either a clockspring issue or a chaffed wire in the column, could even be behind the airbag.

Do the switches light up? I ask this because they may have been left unplugged if someone had the airbag out.

The pressure switch code is likely the pressure switch at the firewall for the AC. Ok for now.

Remove the Accelerator cable from the Throttle body, manually move the butterfly and let it close by itself.

Does it close? 

Then try the same with the cruise cable disconnected.

From there check the cable that goes to the pedal and see if it is kinked anywhere in its tight journey from the TB to the firewall. 

Glad you are feeling Better. No time to get sick

[BodybyFisher]

The main symptom was that your idle was racing correct?

[jndnaps]

2 hours ago, rockfangd said:

Cruise cable not necessary to be hooked up.

One of your steering wheel control switches is either stuck or shorted.

See each one of them when pressed provides a different specific resistance value that is translated by the  computer and sent to the IPC (iirc) Then it is sent out to the module from there. This makes me wonder if you have either a clockspring issue or a chaffed wire in the column, could even be behind the airbag.

Do the switches light up? I ask this because they may have been left unplugged if someone had the airbag out.

The pressure switch code is likely the pressure switch at the firewall for the AC. Ok for now.

Remove the Accelerator cable from the Throttle body, manually move the butterfly and let it close by itself.

Does it close? 

Then try the same with the cruise cable disconnected.

From there check the cable that goes to the pedal and see if it is kinked anywhere in its tight journey from the TB to the firewall. 

Glad you are feeling Better. No time to get sick

Yes, the switches light up, but they don't work anymore. The radio will change stations by itself and the volume will go up or down by itself. The A/C will change the temps to opposite of what is set. If I have it set to 60 it'll go to 90 and vise versa. Same with the fan. If it's on high, it'll go low and vise versa. Never had the airbag out or the steering wheel touched. 

I'll check the cables tomorrow.. 

Thanks! 

[jndnaps]

13 minutes ago, BodybyFisher said:

The main symptom was that your idle was racing correct?

Yes! It's really bad. When I got home and put the car in park it jumps up to 3000 + then when I restart it right away it starts around 800 to 1000.. When I first started the car it started at around 1500 cold start. Most of the time if I restart the car when sitting at a light the idle will drop down a lot.  

[BodybyFisher]

Disconnect the cruise control cable its ok.

I want you to diagnose this by removing the throttle cable and feeling the throttle body plate opening and closing for smooth motion with nothing obstructing or binding it throughout its full range.  It should have a strong spring pressure to close it also.  The rod/shaft that holds the plate goes through the throttle body on both sides on carburators wear used to occur, we have not seen owners complaining about worn out shafts/rods, but look it over.  It should open and close smoothly with little or no play in the shaft that might interfere with its closing.

Manipulate the cable in both directions.to see if it feels to be binding or gummed up and sticking.  It should be free.   Go down and look at the end that connects to the pedal look for freying, kinking, binding or mis-routing.

When you reassemble it, the throttle should sit on its stop every time.

It sounds like you might have a cable problem.

[jndnaps]

OK, gonna take a few days or so to get to this. Not even gonna hint as to what the heck happened to me today.. All I can say is WOW! oh, and OUCH! LOL... I'll be back.. Thanks again guys! 

[BodybyFisher]

13 hours ago, jndnaps said:

OK, gonna take a few days or so to get to this. Not even gonna hint as to what the heck happened to me today.. All I can say is WOW! oh, and OUCH! LOL... I'll be back.. Thanks again guys! 

Hang in there, we will be here

[rockfangd]

Sure will. We live here😁

[winterset]

I can only speak in general terms about what triggers a request for increased engine rpm, but the pcm uses the isc motor to perform this request. I keep a clean throttle body, but as we know, the Northstars tend to have clean exhausts and gummed up throttle bodies.  Anywho, you will be surprised that even with a good throttle body cleaning, the valve to control the idle might be sticking and remain gummed up even after a tb cleaning. What happens then is pcm sends a request to increase rpm, the isc doesnt respond, so additional requests are sent where the valve opens to an extreme level and then the idle is too high. The pcm then keeps trying to lower it, in increments, but it is stuck at high idle.  When the car is shut off or started, the isc motor becomes active where it successfully runs thru more extreme steps to increase and decrease idle and returns to its correct default starting position.  Also, sometims after i shut my car off, i hear the throttle body clicking for a few minutes, and i traced it back to the isc.  I never removd or cleaned my isc motor on my 96 Deville,, but you might consider that there might be some gum and tar causing it to stick and malfunction. I have removd and cleaned for other GM engines.  

[jndnaps]

On 12/9/2018 at 12:47 AM, winterset said:

I can only speak in general terms about what triggers a request for increased engine rpm, but the pcm uses the isc motor to perform this request. I keep a clean throttle body, but as we know, the Northstars tend to have clean exhausts and gummed up throttle bodies.  Anywho, you will be surprised that even with a good throttle body cleaning, the valve to control the idle might be sticking and remain gummed up even after a tb cleaning. What happens then is pcm sends a request to increase rpm, the isc doesnt respond, so additional requests are sent where the valve opens to an extreme level and then the idle is too high. The pcm then keeps trying to lower it, in increments, but it is stuck at high idle.  When the car is shut off or started, the isc motor becomes active where it successfully runs thru more extreme steps to increase and decrease idle and returns to its correct default starting position.  Also, sometims after i shut my car off, i hear the throttle body clicking for a few minutes, and i traced it back to the isc.  I never removd or cleaned my isc motor on my 96 Deville,, but you might consider that there might be some gum and tar causing it to stick and malfunction. I have removd and cleaned for other GM engines.  

Winterset, yes, I have cleaned it and that didn't work. Then I replaced it and still have the problem. So unless I got a bad one, I'm guessing that's not the problem. I wish that was it because this is driving me crazy. 

[BodybyFisher]

How is this job going, still have the car?  It should be nice and cool down there now.  

[jndnaps]

On 2/15/2019 at 6:11 PM, BodybyFisher said:

How is this job going, still have the car?  It should be nice and cool down there now.  

Yes, I re cleaned the TB and checked the return spring and all was good. The throttle cable was moving freely. I took the car to another mechanic just to ask them about a repair I need for the wifes car and they heard the high idle and looked at the car real quick. They ended up using that "Kent Moore tool - J-37027-A"  that Logan was talking about and lowered the idle on it and now it idles at around 600 to 700 RPM's with the A/C on and I'm leaving the IAC unplugged and it's been fine. They did it for free. So it's been a week and I can live with it for now. Still need the car so if it stays this way I'm good to go and not worrying about it till it acts up again. 

[rockfangd]

Well I suppose that as long as it idles good and you are happy then that is all that counts.

Thanks for the update. Been wondering

[jndnaps]

1 hour ago, rockfangd said:

Well I suppose that as long as it idles good and you are happy then that is all that counts.

Thanks for the update. Been wondering

Yeah, been out of commission for a while and didn't get back to it till a couple weeks ago. I'd like to know what the problem is, but I'm just at the point where I just don't want to mess with it anymore. I put it on Craigslist a little over a month ago with the pics I have of the car all cleaned up before the damage and then two of the damage and mentioned the extremely hight idle and listed it for $1,200 OBO. The next morning I had almost 20 messages on it. A few were bogus, but most were interested. So if it stays this way when I'm ready to move on I'll list it for real..  Better than scraping it.. 😀 👍