Chris Posted September 2, 2012 Report Share Posted September 2, 2012 Hi guys, A few times I've been at work, some one has come in to tell me my trunk was open. I assumed I'd hit the keyfob accidentally, so took the keyfob off my keychain. It kept happening (including once when it opened overnight outside at a friend's apartment building!). When I put it into valet mode (disabling power trunk), it won't open. Based on this, I assume it's either a bad trunk release switch, or trunk relay. Because it's so intermittant (maybe happens once a week), it's difficult to troubleshoot. Do you guys have any experience? The trunk switch is $50 and the relay is $8. I might try both just to be safe unless you guys have some feed back. Thanks Chris -Chris Link to comment Share on other sites More sharing options...
JimD Posted September 2, 2012 Report Share Posted September 2, 2012 Display your trouble codes and see if there are any modules reporting B1327. Jim Drive your car. Use your cell phone. CHOOSE ONE ! Link to comment Share on other sites More sharing options...
Chris Posted September 2, 2012 Author Report Share Posted September 2, 2012 Thanks JimD, there are no codes showing. But I will turn off the Valet mode for a while and see if that code is set. Chris -Chris Link to comment Share on other sites More sharing options...
Cadillac Jim Posted September 2, 2012 Report Share Posted September 2, 2012 You might start by running the OBD codes and posting them here. There is a module, the RFA (remote function actuator) module, that reports a few codes (P1695, P1696) in addition to the B1327 code mentioned by JimD. -- 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...
WarrenJ Posted September 3, 2012 Report Share Posted September 3, 2012 This might help some... There is no means of avoiding the final collapse of a boom brought about by credit expansion. The alternative is only whether the crisis should come sooner as the result of a voluntary abandonment of further credit expansion, or later as a final and total catastrophe of the currency system involved. - Ludwig von Mises Link to comment Share on other sites More sharing options...
rockfangd Posted September 3, 2012 Report Share Posted September 3, 2012 check your battery. this can happen with a low battery condition. GM FAN FOREVER Nice, clean, luxury= fine automobile Link to comment Share on other sites More sharing options...
Texas Jim Posted September 3, 2012 Report Share Posted September 3, 2012 +1 on checking the battery Link to comment Share on other sites More sharing options...
Chris Posted September 3, 2012 Author Report Share Posted September 3, 2012 I think you guys diagnosed a problem I didn't even know I had. With the ignition off, my battery voltage is 12.6V. With the ignition in the "run" position, it drops to 12.4V. My understanding is that with no draw/load, the battery should put out 13.6V. The battery looks brand new (great location under the seat!) but may very well be original with the car (there is a data sticker on it, but all the writing wiped off when I brushed it... ack). I think unknowingly having a bad battery burned out two voltage regulators on my last car (STS), so I'm glad I can fix this if it is indeed too low. Think I need a new battery? Thanks guys! edit: These voltages were taken about 1 hour after driving the car for ~45 minutes, so I don't think any "phantom draws" are running the battery down. -Chris Link to comment Share on other sites More sharing options...
JimD Posted September 3, 2012 Report Share Posted September 3, 2012 alt I think you guys diagnosed a problem I didn't even know I had. With the ignition off, my battery voltage is 12.6V. With the ignition in the "run" position, it drops to 12.4V. If that "run" position voltage is with the engine OFF, your measured voltages are perfect. However, if that "run" position voltage is with the engine running, you have a potential charging system issue. My understanding is that with no draw/load, the battery should put out 13.6V. A fully charged lead-acid battery terminal voltage will be 12.6 Volts maximum. A fully charged lead-acid battery connected to a properly operating alternator will display a terminal voltage of 13 Volts to 16 Volts with the alternator internal voltage regulator aiming for the middle of the range (14.5 Volts). Those numbers will vary depending on a number of factors one of which is temperature. Are you reading voltage with an external voltmeter or relying on the DIC display?? The battery looks brand new (great location under the seat!) but may very well be original with the car (there is a data sticker on it, but all the writing wiped off when I brushed it... ack). Highly unlikely that would be the original battery in a 10 to 11 year old car. Think I need a new battery? Only way to know for sure is to have your battery load tested. Jim Drive your car. Use your cell phone. CHOOSE ONE ! Link to comment Share on other sites More sharing options...
Chris Posted September 3, 2012 Author Report Share Posted September 3, 2012 A fully charged lead-acid battery terminal voltage will be 12.6 Volts maximum. A fully charged lead-acid battery connected to a properly operating alternator will display a terminal voltage of 13 Volts to 16 Volts with the alternator internal voltage regulator aiming for the middle of the range (14.5 Volts). Those numbers will vary depending on a number of factors one of which is temperature. Are you reading voltage with an external voltmeter or relying on the DIC display?? I was thinking about it and got to thinking that seemed normal. Also tried my parents Maxima and got the same results. I measured the voltage across the battery. The DIC in the "run" position (engine off) was the same as the voltmeter. With the engine running, the voltage on DIC is around 14.5V. You're also right about age of the battery - it was replaced at the dealership in December 2008, approx 30k miles ago. I'll get the battery load tested to rule it out from being the cause of the trunk release issue. -Chris Link to comment Share on other sites More sharing options...
Cadillac Jim Posted September 4, 2012 Report Share Posted September 4, 2012 When the battery is tested, make sure that the cables and terminals are cleaned. Bad contacts there can cause symptoms similar to a low or bad battery. -- 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...
Chris Posted September 6, 2012 Author Report Share Posted September 6, 2012 Display your trouble codes and see if there are any modules reporting B1327. You might start by running the OBD codes and posting them here. There is a module, the RFA (remote function actuator) module, that reports a few codes (P1695, P1696) in addition to the B1327 code mentioned by JimD. These are the codes I pulled: DTC P0410 Secondary Air Injection (AIR) System DTC P1570 Traction Control Active - Cruise Control Disabled DTC U1255 Class 2 Communication Malfunction I'm getting P0410 because I pulled the fuse on the smog pump, and had a history P1570 because I had the front of the car off the ground and put it in drive. I also wrote down B1004 but apparently that isnt a valid code! Going to stop and get the battery load tested on my way home tomorrow. Will post back then. -Chris Link to comment Share on other sites More sharing options...
Cadillac Jim Posted September 6, 2012 Report Share Posted September 6, 2012 B1004 Keep Alive Memory (KAM) The PZM throws this one when the battery is disconnected. -- 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...
Chris Posted September 7, 2012 Author Report Share Posted September 7, 2012 Thanks Jim. Kind of strange though, since I'd never disconnected the battery prior to today (and check/reset the codes every few months) I took the battery to be tested today. Had to take the battery into the store (otherwise they wanted $20 to test it!). It load tested ok. But I noticed a lot of corrosion on the bolt which connects the negative battery terminal to the frame of the car. I brushed it off with a wire brush. Hoping that might have been the problem. Are there any other contact areas which tend to corrode? All the other connections under the back seat were clean (though I brushed them anyways). Was also pleasantly surprised that the clock and radio presets remained in tact, despite 20+ minutes of no battery. Must be a big capacitor? Though I did need to do a re-learn for express-up power windows. Hope everyone has a great weekend! -Chris Link to comment Share on other sites More sharing options...
JimD Posted September 7, 2012 Report Share Posted September 7, 2012 ....I took the battery to be tested today. Had to take the battery into the store (otherwise they wanted $20 to test it!). It load tested ok. But I noticed a lot of corrosion on the bolt which connects the negative battery terminal to the frame of the car. I brushed it off with a wire brush. Hoping that might have been the problem. Are there any other contact areas which tend to corrode? Visible corrosion on that chassis ground bolt "could be" the result of the bolt not being properly torqued. If you cleaned up the threads and the bottom surface of the bolt shoulder as well as the top surface of the cable end connector you have done as much as you can do. Except for maybe running the bolt in and out of the threaded nut plate several times to clean up the actual chassis connection. You probably noticed the area surrounding that bolt hole is painted. That tells you the chassis ground connection is completed from the top surface of the cable end connector to the bottom surface of the bolt shoulder to the threads. Clean and tight is always good. Was also pleasantly surprised that the clock and radio presets remained in tact, despite 20+ minutes of no battery. Must be a big capacitor? Nope. The same kind of memory device that retains odometer reading. Now you are ready to see if the original problem still exists. Jim Drive your car. Use your cell phone. CHOOSE ONE ! Link to comment Share on other sites More sharing options...
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