Buying Used C5 and Checking Codes
Thread Starter
Intermediate
Joined: Feb 2006
Posts: 33
Likes: 0
From: Auburndale FL
Buying Used C5 and Checking Codes
When buying a used C5 I want take make sure that any errors codes, CEL's, etc. have not been recently cleared out.
Will the following DTC show any recent error codes that might be hidden by a clear or pulled battery cable? Just looking for a way to protect myself from shady used car purchases.
Will the following procedure posted by a forum member below be able to do this?
Will the following DTC show any recent error codes that might be hidden by a clear or pulled battery cable? Just looking for a way to protect myself from shady used car purchases.
Will the following procedure posted by a forum member below be able to do this?
Cobra4B: Here's how "DIY Service Techs will be most interested in the IPC's display of diagnostic trouble codes (DTC) for all modules that transmit them. The "diagnostic display" mode is entered with the following procedure: 1) turn on the ignition but don't start the engine. 2) press the "reset" button to turn off any warning messages 2) press and hold "options" and 4) while holding "options", press "fuel" four times within a 10-second period."
Race Director
Joined: Nov 2003
Posts: 12,346
Likes: 5
From: Mustang OK
I'm not sure that I'm competely following your line of questioning, but Diagnostic Trouble Codes (DTCs) are the trouble or error codes that can display when the car's on-board diagnostics are run. With a CEL, one or more DTCs will usually be be set. However, DTCs can be easily cleared using the RESET button, so the absence of any DTCs when running the car's on-board diagnostic doesn't necessarily tell you anything.
The following is one of the best sites that I've found on running the C5's on-board diagnostics and it has the DTCs specific to each model year. It also has instruction for clearing the DTCs. After selecting the model year, be sure to click on READ MORE toward the bottom of the next page that appears to see all the DTCs specific to that model year.
Computer Codes and DTC Information
HTH
The following is one of the best sites that I've found on running the C5's on-board diagnostics and it has the DTCs specific to each model year. It also has instruction for clearing the DTCs. After selecting the model year, be sure to click on READ MORE toward the bottom of the next page that appears to see all the DTCs specific to that model year.
Computer Codes and DTC Information
HTH
Last edited by GrayC5; Aug 11, 2006 at 04:38 AM. Reason: Added link to DTCs.
Safety Car
Joined: May 2006
Posts: 4,288
Likes: 129
From: Providence Forge, VA
St. Jude Donor '08-'09-'10-'11-'12
Well, I'd guess most of us have cleared a lot codes over the years. Certainly the car can pile up a lot of H codes over time. Of course you'll want to get the service history, Carfax, and other background stuff done. Take the car for one or two good test drives (include highway speeds) and then check the codes yourself after each drive. If its something major the code will probably show up. I'd recommend printing out the DTC list (its several pages) and take it with you (I keep the list in my glovebox). Go through the DIC in manual mode, take your time, and look up any codes you find. Some are serious, some aren't. If you're unsure, post the codes here and someone will help you. Good luck! 
