P20B9
Reductant Heater "A" Control Circuit/Open
DTC P20B9, sometimes indicated as P20B900 is an OBD diagnostic trouble code indicating a manufacturer-specific fault with the vehicle powertrain (i.e. engine and gearbox). This code identifies an error with the air/fuel mixture causing reductant heater "a" control circuit/open.
The reductant heater "A" control circuit is open, which means the reductant heater is not receiving power. This can be caused by a number of things, including a faulty circuit breaker, a blown fuse, or a defective reductant heater.
The first thing to check is the circuit breaker or fuse. If they are OK, then the reductant heater may be defective and needs to be replaced.
- P20B9: Reductant Heater A Control Circuit/Open
- P20B9: Reductant Heater "A" Control Circuit/Open
- P20B9: Reductant heater control A – open circuit
- P20B9 00: Reductant heater control A - open circuit
Bulletins are notices put out by manufacturers in conjunction with the NHTSA to notify the public of manufacturing issues or changes.
- 167-B1806-2 - ENGINE AND ENGINE COOLING
HINO: Sb-18-013 coe heated def line dtc's P20BD, P20B9, or P20C1
2013 CHEVROLET SILVERADO 2500 with 111000. miles
Special coverage adjustment 29400 diesel emission fluid tank reservoir was created. Nhtsa id number:10135147 special coverage extends to 2013 silverado 3500 model, but not 2013 Silverado 2500 per the dealer. I own the 2500 which is currently suffering from obd error code P20B9. Same code applies to 3500 from what i've read. This error occurred while driving on the highway. I was notified by the dash that i had 100 miles before limited power and speed would be applied. Fortunately i was 40 miles from home. Both trucks are the same other than the 3500 has dual wheels ("dully") and larger rear axels from what i was told at the dealer. Other systems, including the diesel-emission-reduction fluid system (def). Both models appear to have the same system including the tank reservoir and components. In fact when you order replacement parts for this issue, increased def tank-heater resistance, the part being replaced is the same be it a 3500 or 2500. Curious why the 3500 model is covered under the special coverage and the 2500 is not? Why 2013 2500 not on list of (14) products, if it's the same as 2013 3500 when both models: -get the same obd code: P20B9 - replacement part (23379348) for 2500 per dealer is found on the nhtsa's special coverage list - replacement part per dealer (23379348) is the same for 3500 and 2500 per gm site and rockauto.Com thank you in advance, fidel
UNKNOWN OR OTHER, UNKNOWN OR OTHER
2011 CHEVROLET SILVERADO 2500 with 135000. miles
I started my 2011 chevy Silverado 2500 6.6l diesel and my def and check engine light came on the dash telling me to check owners manual now. I plugged in my code reader to the vehicle and it gave me a code reading 'P20B9 reductant heater a control circuit open'. From what i could research online this seems to be a very common issue in these lml diesel trucks with the def system.
UNKNOWN OR OTHER,
2011 GMC SIERRA 2500 with 155000. miles
Def light came on and the display saying service exhaust fuel system and refer to manual. That gave me nothing. The codes that came up is P2209 and P20B9. So the heater in the def tank is broken and the nox reading is wrong or has gone out. Then my speed was reduced to max 55 mph. Dealer said it would be $1500 to fix but after reading forums on-line there have been a lot is issues with the def system, fixing it, and then still displays issue. Am i going to get this repaired and still have an issue like others?
ENGINE, UNKNOWN OR OTHER