I've Got the Codes Now, Still Baffled!
Thread Starter
Burning Brakes
Joined: Aug 2013
Posts: 952
Likes: 100
From: Lehigh Valley PA
2022 C5 of the Year Finalist - Modified
I've Got the Codes Now, Still Baffled!
Background: Every 10th start or so the car will not start. NO clicking or attempt to turn over, The gauges will or will not work, Lights work, radio works. Then wait 3-5 minutes and after about 5-7 attempts it starts. It idles perfectly and no issues while driving.
Here are the codes:
B2253H Key cylinder switch default RDCM (Right door control module)
B2282H, 12 volt Power Pack Feed #1 LDCM (left door control module)
B2283H 12 volt Power Pack Feed #1 RDCM
B2284/85 H 12 volt Power Pack Feed #2 LDCM & RDCM
P1571 Torgue Signal out of range
P1631 Theft Deterrent Start Enable (Maybe my key is going bad?)
U1016 Normal Software Function, History Status upon ignition starting
U1096 Lost Communication, all modules, datalink (hmmm)
U1255 Lost Communication with XXX (That's what the code lists)
Any of those codes make sense? Not sure about the RDCM & LDCM references from the code listing, Remote Fob works. I always open the car with the remote FOB. Dreading the next bad start. Appreciate any help or suggestion. I have to deal with this sooner or later. On the way to Carlisle Friday! Thank you everyone!
Here are the codes:
B2253H Key cylinder switch default RDCM (Right door control module)
B2282H, 12 volt Power Pack Feed #1 LDCM (left door control module)
B2283H 12 volt Power Pack Feed #1 RDCM
B2284/85 H 12 volt Power Pack Feed #2 LDCM & RDCM
P1571 Torgue Signal out of range
P1631 Theft Deterrent Start Enable (Maybe my key is going bad?)
U1016 Normal Software Function, History Status upon ignition starting
U1096 Lost Communication, all modules, datalink (hmmm)
U1255 Lost Communication with XXX (That's what the code lists)
Any of those codes make sense? Not sure about the RDCM & LDCM references from the code listing, Remote Fob works. I always open the car with the remote FOB. Dreading the next bad start. Appreciate any help or suggestion. I have to deal with this sooner or later. On the way to Carlisle Friday! Thank you everyone!
Last edited by 57gman; Aug 19, 2018 at 11:40 AM.
Thread Starter
Burning Brakes
Joined: Aug 2013
Posts: 952
Likes: 100
From: Lehigh Valley PA
2022 C5 of the Year Finalist - Modified
Code in RED above is the most likely reason for your no start symptom. Meaning of P1631 is " Theft Deterrent System Password Incorrect".
The pellet on your key is read by the BCM and translated to a password that the BCM sends to the PCM for comparison against a stored password that the PCM has. There was a mismatch so the BCM does NOT enable the starter since it thinks someone is trying to steal the car. You should watch the SECURITY light on the dash the next time the symptom occurs. It most likely is on solid when the key is left in the ON position after trying to crank the engine after a no crank condition.
I suggest that you CLEAR all the codes that the car has and then take the car for a nice drive (assuming you can get it started ) and when you return pull the codes BEFORE you shut off the engine. To pull codes with the engine running use the RESET button to clear all messages displayed in the DIC and then pull codes as normal. Codes that have returned after being cleared are the ones that need attention.
As far as the pellet not being read correctly there are a few things you can try to alleviate that issue. Use an eraser on a pencil to clean off any tarnish on both sides of the pellet on the key and then use a lint free cloth with a little denatured alcohol to clean the pellet. Get some electrical contact cleaner. Available in small aerosol container at most parts stores. Spray some into the key cylinder and then insert and remove the key 10 or 12 times wiping off the key with a lint free cloth between each insertion. You might want to repeat that to insure that the surfaces inside the key cylinder that pass across the key pellet are clean and free of any tarnish.
Post back the results form all of the above.
If you have the same symptoms again after the above actions post all the codes again. May be something other than the pellet being read correctly as there are MANY different causes of NO CRANK on a C5. Other causes of NO CRANK are poor battery connections including at the starter solenoid, bad starter or solenoid, bad or poor grounds......etc.
The pellet on your key is read by the BCM and translated to a password that the BCM sends to the PCM for comparison against a stored password that the PCM has. There was a mismatch so the BCM does NOT enable the starter since it thinks someone is trying to steal the car. You should watch the SECURITY light on the dash the next time the symptom occurs. It most likely is on solid when the key is left in the ON position after trying to crank the engine after a no crank condition.
I suggest that you CLEAR all the codes that the car has and then take the car for a nice drive (assuming you can get it started ) and when you return pull the codes BEFORE you shut off the engine. To pull codes with the engine running use the RESET button to clear all messages displayed in the DIC and then pull codes as normal. Codes that have returned after being cleared are the ones that need attention.
As far as the pellet not being read correctly there are a few things you can try to alleviate that issue. Use an eraser on a pencil to clean off any tarnish on both sides of the pellet on the key and then use a lint free cloth with a little denatured alcohol to clean the pellet. Get some electrical contact cleaner. Available in small aerosol container at most parts stores. Spray some into the key cylinder and then insert and remove the key 10 or 12 times wiping off the key with a lint free cloth between each insertion. You might want to repeat that to insure that the surfaces inside the key cylinder that pass across the key pellet are clean and free of any tarnish.
Post back the results form all of the above.
If you have the same symptoms again after the above actions post all the codes again. May be something other than the pellet being read correctly as there are MANY different causes of NO CRANK on a C5. Other causes of NO CRANK are poor battery connections including at the starter solenoid, bad starter or solenoid, bad or poor grounds......etc.
Thread Starter
Burning Brakes
Joined: Aug 2013
Posts: 952
Likes: 100
From: Lehigh Valley PA
2022 C5 of the Year Finalist - Modified
I did exactly what 8vette7 suggested with the electric contact cleaner and removed all codes and the issue has not returned! Thank you. Problem solved for $10.59!
