For 1990-2009 cars

# Red OnStar LED , No Keypad Response When Pushed DTC B2476 - kw inoperative UE1

Subject: | Red OnStar LED, No Keypad Response When Pushed DTC B2476

Models: | .

When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

### Condition/Concern:

Customer may comment of a red LED on the OnStar button assembly, and gets no response when any OnStar button is pushed. Technician will find DTC B2476 and the service OnStar MIL may be illuminated if equipped. Diagnostic in SI may not be robust enough for the technician to effect a proper repair.

### Recommendation/Instructions:

SI indicates the keypad signal circuit voltage to the VCIM should be more than 2.8 volts and less than 3.2 volts. In reality, the voltage on the keypad signal circuit should be 0 volts until a button is pressed. When the white dot button is pressed, the voltage should be 0.3 volts. When the OnStar button is pressed, the voltage should be 1.3 volts. When the Emergency button is pressed, the voltage should be 2.3 volts. These voltage readings should be taken at the VCIM or VIU.

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Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.

### Models:

(1998-2005 all vehicles equipped with OnStar)

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