Skip the auto shop - Our mechanics make house calls

B1947 OBD-II Trouble Code: Climate Control A/C Post Evaporator Sensor Circuit Short To Ground

diagnostic check engine light

B1947 code definition

The B1947 code is a manufacturer-specific body code related to the climate control system. In this case, the engine control module (ECM) has detected a fault in the evaporator sensor for the climate control system or A/C.

What the B1947 code means

A code B1947 will be stored when the ECM detects a voltage signal from the post evaporator sensor that is signaling a short, or a signal other than approximately 5 volts (depending on vehicle make and model).

What causes the B1947 code?

Several problems may cause a B1947 code including:

  • Malfunctioning, damaged, or defective evaporator temperature sensor
  • Damaged or defective climate control unit
  • Open or short circuit in wiring harness between climate control unit and evaporator temperature sensor

What are the symptoms of the B1947 code?

Symptoms of a B1947 code may include: * Check engine or warning light may illuminate * Climate control or A/C may not work correctly * There may be no symptoms other than a stored B1947 code

How does a mechanic diagnose the B1947 code?

A mechanic may use several methods to diagnose a B1947 trouble code, including:

  • Utilize an OBD-II scanner to check for a stored B1947 trouble code
  • Visually inspect wiring and electrical components related to the evaporator temperature sensor for signs of damage
  • Inspect the evaporator temperature sensor
  • Disconnect climate control unit and evaporator temperature sensor connector and check for an open circuit in the wiring harness between the T-B and U-A terminals of the climate control unit and evaporator temperature sensor
  • Turn the ignition to the “on” position and using an ohmmeter to inspect voltage at Terminal T of the climate control unit terminal
  • Check if voltage is approximately 5 volts (may vary slightly depending on vehicle make and model, it is recommended to always consult your vehicle’s service manual)

How serious is the B1947 code?

Because a vehicle’s safe driving operation most likely will not be impacted due to faults that store a B1947 code, this code is not considered to be a serious code. When this code appears, it is recommended to take your vehicle to your local service center or mechanic for repair and diagnosis as soon as possible.

What repairs can fix the B1947 code?

Several repairs can fix a B1947 trouble code and include:

  • Repair or replace damaged or shorted electrical wiring and related components
  • Replace the damaged or defective evaporator temperature sensor
  • Repair any damaged or defective wiring harness between the T-B or U-A terminals
  • Replace damaged or defective climate control unit
  • Clear all codes, test-drive the vehicle, and rescan to see if any codes reappear

Additional information related to a B1947 code

It is always recommended to take all proper safety precautions when working with the electrical components of your vehicle and to carefully follow service instructions. With more complicated electrical repairs, it is recommended to seek assistance from a professional.

Need help with a B1947 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

Symptoms of a Bad or Failing Flexible Clutch Hose
Common signs include difficulty shifting, low clutch fluid, and feeling no resistance at the clutch pedal.
How to Buy Fuel Treatments
Adding a fuel additive to your gas tank when you fill up is one way to clean vital engine parts of deposits, improve the performance of your engine,...
How to Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...


Related questions

Q: Stalls when turning or at a stop

Hi there. The first step is to check for any problem codes stored by engine management. This can save a lot of time money when diagnosing drive-ability problems. Most auto parts stores will do this for free. Several problems could...

Q: What would cause brand new O2 sensors to give codes 172, 173, 176, and 177, rich and lean conditions, both sides at the same time?

When it comes to across-the-board codes being set such as this, it is usually a result of something "upstream" creating the condition to set all these codes. For instance, it is rare for both O2 sensors to fail at exactly...

Q: P0301 and P0411 codes on vw Passat 2003 1.8lt turbo

Fault code P0301 is a misfire on cylinder # 1 and P0411 is a fault for Incorrect Secondary Air Injection. Trouble code P0301 is most likely due to a faulty ignition coil. To verify before purchasing one, try swapping say...