tannertaylormusic Posted January 6, 2011 Report Share Posted January 6, 2011 Ok, after almost a year of no major Caddy issues my car freaked out on me tonight on the freeway to and from work. I'm pulling these PCM Current Codes: P0174 P0171 P0503 My digital Speedometer was going wild as well as RPM's. Just had the oil changed yesterday, but I'm assuming that has nothing to do with it running lean. After the problem started today I figured maybe I had wore out the fuel pump or there was condensation in the tank, so I filled the tank and added a bit of that "no freeze" stuff to the mixture. This has to be a bad sensor somewhere - otherwise my speedometer and RPMs wouldn't be jumping around right? The car also seems to hesitate when this happens. Runs pretty well up to 40 MPH, then the freakout begins. Help! I'm not gonna drive her again until I can figure this out. Link to comment Share on other sites More sharing options...
caddypete Posted January 6, 2011 Report Share Posted January 6, 2011 Just had the oil changed yesterday, but I'm assuming that has nothing to do with it running lean. You would think not,but a loose oil cap or dipstick can cause a lean condition. Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 6, 2011 Report Share Posted January 6, 2011 You are also getting P0503 - Vehicle Speed Sensor (VSS) Circuit Intermittent Your speedometer messing up or blanking out because of the VSS sensor or connector. The VSS is located on top of the Right output shaft of the transmission, check its connection is solid and if it is replace the VSS. Those two codes P0171 and P0174 reflect a lean condition on both banks. On later models (not yours) its common for the rubber plenum between the intake and throttle body to tear allowing unmetered air into the intake causing a lean condition on both banks. You need to check for things that cause 1) a reduced FUEL delivery or 2) a vacuum leak that affects both banks Reduced fuel delivery causes, put a fuel pressure gage on the fuel rail, check pressure and check for clogged fuel filter fuel pump output low kinked lines check FPR Check for vacuum leaks vacuum hose at brake booster vacuum hose leak loose intake manifold leak at intake over pressurization valve (do you hear a whistle) leaking seal at throttle body to intake (not likely) cracked intake 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...
CarlaValentine Posted January 6, 2011 Report Share Posted January 6, 2011 You stated that the "digital Speedometer was going wild as well as RPM's". Were the RPM's actually fluctuating? Or was the gauge just going nuts? If it were JUST the gauges then a bad relay could be possible. From what I read elsewhere, a faulty VSS will cause RPM fluctuation and speedometer problems. I do find it odd you got all these codes at once. Is there anything anyone can think of that could have caused BOTH conditions, or at least tie them together? Link to comment Share on other sites More sharing options...
tannertaylormusic Posted January 6, 2011 Author Report Share Posted January 6, 2011 I had not been having any problems with the car until yesterday, when I got all three of these codes at once. Link to comment Share on other sites More sharing options...
tannertaylormusic Posted January 6, 2011 Author Report Share Posted January 6, 2011 You stated that the "digital Speedometer was going wild as well as RPM's". Were the RPM's actually fluctuating? Or was the gauge just going nuts? If it were JUST the gauges then a bad relay could be possible. From what I read elsewhere, a faulty VSS will cause RPM fluctuation and speedometer problems. I do find it odd you got all these codes at once. Is there anything anyone can think of that could have caused BOTH conditions, or at least tie them together? Yes the RPMs were flucuating, as well as my speedometer. I have no idea where the other codes came from, but it's weird to me as well that they all struck at once Link to comment Share on other sites More sharing options...
tannertaylormusic Posted January 6, 2011 Author Report Share Posted January 6, 2011 "Your speedometer messing up or blanking out because of the VSS sensor or connector. The VSS is located on top of the Right output shaft of the transmission, check its connection is solid and if it is replace the VSS." Great - I need specific instructions on where exactly that is. Not much of a car mechanic, but I'm handy. Thanks! Link to comment Share on other sites More sharing options...
tannertaylormusic Posted January 6, 2011 Author Report Share Posted January 6, 2011 P0503 - Vehicle Speed Sensor (VSS) Circuit Intermittent "Your speedometer messing up or blanking out because of the VSS sensor or connector. The VSS is located on top of the Right output shaft of the transmission, check its connection is solid and if it is replace the VSS". I need someone to guide me through this step-by-step to locate and check the VSS conection. Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 6, 2011 Report Share Posted January 6, 2011 That was pretty detailed but Here is the location, see the arrow 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...
Cadillac Jim Posted January 6, 2011 Report Share Posted January 6, 2011 You can see the VSS from behind the right front wheel. It's simpler if you turn the steering all the way to the left before you crawl under the car. It's on top of the half-shaft a few inches from the end of the transmission. It has a connector that pushes down from the top. One thing that can cause P0503 is excess coolant being expelled from the surge tank. The drain hose from under the radiator cap exits in front of the half-shaft and coolant can wet the VSS. In fact, this was one of the first symptoms I had of my HG problem, but it can also be caused by over-filling the coolant, a common thing to happen when you have your car serviced. If the VSS connector seems damp, wipe it off with a paper towel as best you can from under the car. The P0171 and P0174 codes can be caused by a bad air filter. If someone put in the wrong one as part of the service, or shook it out to clean it, that might happen. If the service people did replace it, get a new AC/Delco air filter element and replace it yourself. -- Click Here for CaddyInfo page on "How To" Read Your OBD Codes-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data -- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC Yes, I was Jims_97_ETC before I changed cars. Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 6, 2011 Report Share Posted January 6, 2011 We started to give you info on your VSS here, there is no need to start a second thread on that, I merged that thread here, I posted a photo of its location, access it from the top of the output shaft or through the passenger side wheel well. 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...
tannertaylormusic Posted January 6, 2011 Author Report Share Posted January 6, 2011 Thanks! I'll give it a shot this afternoon. Sorry to ask for so much detail but I'm not very quick when it comes to things I've never dealt with Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 6, 2011 Report Share Posted January 6, 2011 Thanks! I'll give it a shot this afternoon. Sorry to ask for so much detail but I'm not very quick when it comes to things I've never dealt with No biggie, there is not much to say, just check the connection to make sure its clean and tight, if it is, replace the VSS, its held by one 10mm bolt if I recall 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...
tannertaylormusic Posted January 6, 2011 Author Report Share Posted January 6, 2011 Also, I'm just in a rush to get it fixed. Can't miss work tonight - normally I wouldn't start a second thread Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 6, 2011 Report Share Posted January 6, 2011 Also, I'm just in a rush to get it fixed. Can't miss work tonight - normally I wouldn't start a second thread Its ok to start one, but we got down the road on this already, and its more efficient to keep it together. The VCC is the least of your trouble, the lean condition will be the challenge. No doubt the VCC just needs replacing I will say that it is odd that your speedometer and lean condition started at the same time, where did you get your oil changed? 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...
tannertaylormusic Posted January 6, 2011 Author Report Share Posted January 6, 2011 Also, I'm just in a rush to get it fixed. Can't miss work tonight - normally I wouldn't start a second thread Its ok to start one, but we got down the road on this already, and its more efficient to keep it together. The VCC is the least of your trouble, the lean condition will be the challenge. No doubt the VCC just needs replacing I will say that it is odd that your speedometer and lean condition started at the same time, where did you get your oil changed? Precision Tune Auto Care. I won't be going back there again.. All I can say is that it was running fine BEFORE I took it there. Link to comment Share on other sites More sharing options...
BodybyFisher Posted January 6, 2011 Report Share Posted January 6, 2011 It could just be coincidence 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...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.