bruegelpie Posted January 25, 2018 Report Share Posted January 25, 2018 My 2002 Seville SLS at 96K miles has started stalling when accelerating from idle (while at a stop light or stop sign). When I press on the gas peddle it jerks and lurches for a few seconds or it outright stalls all together (sometimes it does both - lurching and then stalling). The car starts without a problem. The car does not stall while I am driving, only when I accelerate from an idle while at a stop light or stop sign. I've read that this could be related to an Exhaust Gas Recirculation Valve. I've also read that it could be the IAC valve. Because it does not happen while I am driving at a steady speed, I read that it would not be the crank position sensor. The only current code the car throws is a MSM B2375, which is a stability sensor code (I think). Advice greatly appreciated! Thanks in advance Link to comment Share on other sites More sharing options...
rockfangd Posted January 26, 2018 Report Share Posted January 26, 2018 MSM is memory seat module. driver seat position sensor IIRC. Does it idle high, low, or anything other than 600-700 at idle? I wonder if it could be the throttle position sensor. So if you ease into it the engine does not stall but if you step on it it stalls. that sound right. Welcome to Caddyinfo. I highly suggest you check fuel pressure also. Low fuel pressure can cause starvation under load. May have enough to start but not enough under load GM FAN FOREVER Nice, clean, luxury= fine automobile Link to comment Share on other sites More sharing options...
bruegelpie Posted January 26, 2018 Author Report Share Posted January 26, 2018 >> So if you ease into it the engine does not stall but if you step on it it stalls. that sound right. Yes, that is exactly what occurs. So you think it is likely the throttle position sensor? Is the fix for that to replace the throttle position sensor? >>I highly suggest you check fuel pressure also. Low fuel pressure can cause starvation under load. May have enough to >>start but not enough under load Any suggestions regarding how I can determine whether it is the throttle position sensor or low fuel pressure? I really appreciate your feedback, since I am far from an expert in this area! Thanks for any further thoughts that you can provide! Link to comment Share on other sites More sharing options...
barczy01 Posted January 26, 2018 Report Share Posted January 26, 2018 clogged cat converter? Link to comment Share on other sites More sharing options...
bruegelpie Posted January 29, 2018 Author Report Share Posted January 29, 2018 Does anyone have any advice regarding how I determine if the problem is: - thrittle position sensor - fuel pressure - clogged cat converter thanks Link to comment Share on other sites More sharing options...
Papalac Posted January 30, 2018 Report Share Posted January 30, 2018 Change the fuel filter and see if it goes away-what can it hurt?probably needs serviced anyway Link to comment Share on other sites More sharing options...
rockfangd Posted January 30, 2018 Report Share Posted January 30, 2018 There is a fuel pressure port under the hood on the driver side of the engine. Should be checked by a professional really as fuel is flammable. Have you ever smelled anything odd? A clogged cat will usually cause a P0420 code and you may smell sulfer (rotten eggs smell) Clogged Cat can also cause the issue you describe as the flow is poor and cannot handle load. Checking with a vacuum gauge should help that, or sometimes in a pinch you can drive it til it is hot and have a look underneath to see if you see anything glowing. GM FAN FOREVER Nice, clean, luxury= fine automobile Link to comment Share on other sites More sharing options...
Dan Posted February 2, 2018 Report Share Posted February 2, 2018 Was the battery changed recently? Sometimes those symptoms can be caused by the computer losing the idle learn because the battery was disconnected. Cleaning the throttle body usually fixes the problem. Or it could be that the throttle body is so dirty that the computer can no longer compensate for it. Link to comment Share on other sites More sharing options...
bruegelpie Posted February 2, 2018 Author Report Share Posted February 2, 2018 >Have you ever smelled anything odd? A clogged cat will usually cause a P0420 code and you may smell sulfer (rotten >eggs smell) No, I haven't smelled anything odd. >Was the battery changed recently? No, the battery was not changed recently. I installed a new battery about a year ago. One other note about the problem - I only notice it occurring when I turn left. It doesn't happen at all (or at least far less often) when I turn right. Link to comment Share on other sites More sharing options...
Jan Olsson Posted February 2, 2018 Report Share Posted February 2, 2018 First of all, check the codes. Otherwise you are just throwing parts at it at your expense and time. Sometimes the codes don't manifest until after a couple of error cycles. If you still don't have codes then I would NOT suspect a clogged cat because they usually let you drive around at reduced rpms and makes the engine stumble at higher rpms. On the other hand your vintage of the STS (2001-2003 I believe) did have some problems with the crankshaft position sensors. They are quite easy to replace. You have to remove the oil filter adapter to reach them and the manual recommends that you replace the quick connect fittings to the oil lines if you have the engine oil cooler. But I insist that you check your codes again and drive around until you get a code before you start throwing parts at it. It can be a numerous count of things. For instance I had a broken wire next to the MAF-sensor that behaved the same way. No codes until I tried a couple more times. If you are really unlucky there will be no codes which is very unusual. Even an intermittent code like for my MAF-sensor problem will be thrown after a while. If I would bet I would bet on the crankshaft position sensors. The car could be driven at any rpm at any speed but just at above idle at take-off it would stall. Link to comment Share on other sites More sharing options...
bruegelpie Posted October 22, 2018 Author Report Share Posted October 22, 2018 An update: The stalling issue basically stopped all summer, but has started stalling again now that the cooler temps have arrived. (I'm in Michigan.) The stalling is continuing, and is particularly bad when turning left. Car completely stalls and needs to be restarted. As I'm trying to determine if it the crankshaft position sensor, throttle position sensor or fuel filter, are any of those affected by cooler weather, which could explain why the issue went away this summer but is back again this fall? Thanks in advance for any help! Link to comment Share on other sites More sharing options...
BodybyFisher Posted October 22, 2018 Report Share Posted October 22, 2018 Have you checked for codes? Post all P codes here. P codes will help direct us. I see JAN asked about them but don't see a reply from you. 2002, did have CAT problems but that wouldn't have gone away in the warm weather Have you checked FUEL PRESSURE with a gage? I would test for fuel pressure immediately, if you can get a gage with a long hose, tape the gage to the windshield and see what happens when it stalls, and when you turn left Please post all P codes. 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 More sharing options...
bruegelpie Posted October 23, 2018 Author Report Share Posted October 23, 2018 Hi, Thanks for the fuel pressure tip. The only code thrown since I reset them was TTM U1016 (History). I'll keep monitoring for codes and post more here when the occur. Thanks again for your help! Link to comment Share on other sites More sharing options...
bruegelpie Posted October 23, 2018 Author Report Share Posted October 23, 2018 Hi, It just threw a couple of P codes: PCM P1106 -Manifold Absolute Pressure (MAP) Sensor Circuit Intermittent High Voltage PCM P1372 - Crankshaft Position Sensor This seems to confirm that the crankshaft position sensor is part of the problem. I'm not sure how to interpret the MAP intermittent high voltage..... Your thoughts? Thank you! Link to comment Share on other sites More sharing options...
BodybyFisher Posted October 23, 2018 Report Share Posted October 23, 2018 There is your answer sir!! Crankshaft position sensor.....( @Jan Olsson nailed this above) I would replace them both, but be very careful to keep the connectors where they belong, top on top and bottom on bottom. Also, you said it.happened on turns, be sure the wires are not hitting up against the exhaust manifold and hit when you turn it is close in there. Make sure the wires are.retained to stay away from the exhaust manifold 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 More sharing options...
BodybyFisher Posted October 23, 2018 Report Share Posted October 23, 2018 The failure you are having stalling and starting right back up is a symptom of a bad crank position sensor so that is definately your problem. If you only want to replace one sensor, I am not sure if we can tell which one it is that is acting up. Check wiring and connectors, it's odd that it happens on turns 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 More sharing options...
BodybyFisher Posted October 23, 2018 Report Share Posted October 23, 2018 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 More sharing options...
BodybyFisher Posted October 23, 2018 Report Share Posted October 23, 2018 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 More sharing options...
bruegelpie Posted October 23, 2018 Author Report Share Posted October 23, 2018 Thank you so much for all of your help!!! Link to comment Share on other sites More sharing options...
Jan Olsson Posted November 16, 2018 Report Share Posted November 16, 2018 On 10/23/2018 at 7:26 PM, BodybyFisher said: There is your answer sir!! Crankshaft position sensor.....( @Jan Olsson nailed this above) I would replace them both, but be very careful to keep the connectors where they belong, top on top and bottom on bottom. Also, you said it.happened on turns, be sure the wires are not hitting up against the exhaust manifold and hit when you turn it is close in there. Make sure the wires are.retained to stay away from the exhaust manifold I would also pull the MAP-connector (it sits on top of the throttle body), spray it with WD40 and disconnect/connect the connector 10-15 times. This excercise cleans the connector and restores the connectivity. Also try to wiggle the cables with car running and see if you can get it to stall. If you have a problem with a bad connection (apart from the oxides that you cleaned away in the previous step) it can either be the connector itself or the wires. I had a code for the MAP-sensor a couple of years ago and a little love and WD40 solved it Link to comment Share on other sites More sharing options...
bruegelpie Posted November 17, 2018 Author Report Share Posted November 17, 2018 UG, I'm still having issues! First I had the MAP sensor replaced and still got the P1372 code. I then had the Crankshaft Position Sensors replaced. The next day I still had the lurching and jerking of the car, particularly when turning left while accelerating from a stop. Can anyone offer suggestions regarding why I would still be having the code after just replacing the Crankshaft Position Sensors? (FYI - the mechanic said they were very difficult to access and replace.) Thanks, Link to comment Share on other sites More sharing options...
Jan Olsson Posted November 18, 2018 Report Share Posted November 18, 2018 19 hours ago, bruegelpie said: UG, I'm still having issues! First I had the MAP sensor replaced and still got the P1372 code. I then had the Crankshaft Position Sensors replaced. The next day I still had the lurching and jerking of the car, particularly when turning left while accelerating from a stop. Can anyone offer suggestions regarding why I would still be having the code after just replacing the Crankshaft Position Sensors? (FYI - the mechanic said they were very difficult to access and replace.) Thanks, The P1372 code and MAP sensor are unrelated. P1106 was the code for the MAP sensor so it makes sence that you still got the P1372 BEFORE the Crankshaft Position Sensors were replaced. Are there still codes precent after the Crankshaft Position Sensors were replaced? If not then there is another problem and it has propably something to do with the MAP connections since it is the only other code you have got. From my own experiences it seems rare that a sensor breaks. Usually bad connections and damaged wiring seems to be the problem. The Crankshaft Position Sensors are located on a tight spot but not that difficult to replace after you remove the oil filter adapter. I've done it myself Link to comment Share on other sites More sharing options...
bruegelpie Posted November 18, 2018 Author Report Share Posted November 18, 2018 Sorry if I wasn't clear. I received the P1372 Crankshaft Position Sensor code AFTER the new crankshaft position sensors were replaced!! The code should have stopped after the new sensors were put in place, shouldn't they! UGG!! Why would I still get a code after the sensors were replaced? Thanks! Link to comment Share on other sites More sharing options...
BodybyFisher Posted November 21, 2018 Report Share Posted November 21, 2018 Were the codes deleted after the crank sensors were replaced? The battery should be disconnected to reboot the system. What is the status now? 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 More sharing options...
bruegelpie Posted November 21, 2018 Author Report Share Posted November 21, 2018 I've cleared the codes now, so if the codes appear again I know that it will be new. (I think the code was new, but with your step suggested above, I will know for certain next time.) I will disconnect the battery and reboot the system. The car continues to stutter when I turn left. The car doesn't stall, but it lurches and jerks like before the PAM was replaced and the crank position sensors were replaced. Thanks for your help! Link to comment Share on other sites More sharing options...
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