P20B9 " High Reductant Tank Heater Internal Resistance "

[GL1800]

On a trip through eastern Oregon/Idaho at 4:00am a cel came on with the DEF fault light also. The DIC said to service DEF system see dealer. I was in the middle of nowhere in a snow storm at the time. I kept driving and shortly a DIC message came up stating that speed would be limited to 55 mph at next engine start. Now I was starting to get concerned as it was a long ways to anywhere! I called OnStar and was told that the code was for the DEF system and it could be fixed at my convenience! I called a dealer in Nampa Idaho and they said bring it in and we will check it out. 2.5 hours later I pulled into Edmark Superstore in Nampa Idaho . My pickup was taken right in and in about an hour I was informed that the DEF tank had to be replaced. The good news was that they had one in stock. About 3 hours later and $660 I was back on the road.

I must give a well done to Edmark Superstore. They are a very big and busy dealership. They took very good care of me and went out of the way to keep me informed in what was happening. I just wished they were closer to me!

[DmaxMaverick]

Thanks for the info! I've read about this issue with most of the DEF equipped vehicles. What was the outside temp at startup? How long since the warmup and what was the outside temp at the time? There is a work-around to delay the repair, if it isn't too cold. Clearing the code should delay the reduced-speed message until the next fault, if the system is already warm.

[GL1800]

Thanks for the info! I've read about this issue with most of the DEF equipped vehicles. What was the outside temp at startup? How long since the warmup and what was the outside temp at the time? There is a work-around to delay the repair, if it isn't too cold. Clearing the code should delay the reduced-speed message until the next fault, if the system is already warm.

Outside temp was 60 degrees plus at start up. The warning came on after 3 hours of driving. I asked the tech if the code could be cleared so I could make it back to my dealer and was told that it wasn't possible.

[GL1800]

My truck has 104,000 miles on it.