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B1270 is a diagnostic trouble code (DTC) for "Servo Motor Potentiometer Defrost Circuit Short to Battery". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.
The B1270 trouble code identifies a malfunction with the servo motor potentiometer defrost circuit.
The B1270 code is a generic OBD-II trouble code that detects an error with the servo motor potentiometer defrost circuit. The potentiometer controls voltage output into the defrost system, which allows the defroster to operate on a scale, rather than just on or off. When a circuit error is detected from the servo motor potentiometer, then the B1270 trouble code will be stored.
Potential causes of the B1270 trouble code include:
The B1270 code may be accompanied by the check engine soon Warning Light, or a flashing climate control light. It is common for the defroster to not work properly when this code is detected.
The B1270 code will be diagnosed using a standard OBD-II trouble code scanner. A trustworthy mechanic will use the scanner to view the freeze frame data, and gather information about the code. The mechanic will also look to see if any other codes have been detected. In the event that there are numerous codes present, then the technician will need to address them in the order in which they are displayed on the scanner. The codes will then need to be reset, and the vehicle restarted, to see if the B1270 code returns. If not, then it was most likely triggered inaccurately, or represents an intermittent error.
If the B1270 code remains detected, then the mechanic will need to visually inspect the electrical components associated with the defrost system. All fuses, wires, and connectors should be examined, and the circuit will then need to be tested. Next, the servo motor and potentiometer will be thoroughly inspected.
After any replacements or repairs, the mechanic should reset the trouble codes, restart the vehicle, and check to see if the B1270 code is still detected. This helps the mechanic know when the issue is resolved.
The most frequently made error when diagnosing the B1270 code is the failure to properly abide by the OBD-II diagnosis protocol. It is extremely important that mechanics follow the protocol at all times, to ensure that all diagnoses and repairs are efficient and accurate.
Often servo motors and potentiometers are unnecessarily replaced before electrical components are inspected.
The B1270 trouble code won’t keep a vehicle from being drivable, but it may keep the defrost system from working. The defrost system is an important safety feature that can greatly aid driver visibility, so a vehicle with this code should be inspected as soon as it is convenient.
Potential repairs for the B1270 code are:
It is extremely rare for the B1270 code to be triggered by a defective control module, so all potential causes of the code should be checked before a failed PCM, body control module, or climate control module is suspected. In the unlikely event that a control module does need to be replaced, it will also need to be reprogrammed.
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