GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    •  Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    •  Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B1422: Device Power Moding Malfunction

Circuit Description

The TV antenna module monitors its power supply.

Conditions for Running the DTC

    • Radio ON.
    • Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

The antenna module detects that the voltage has dropped below 8.3 volts for 80 msec.

Actions Taken When the DTC Sets

TV is not selectable from the radio.

Conditions for Clearing the DTC

    • The condition responsible for setting the DTC no longer exists.
    • A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

Circuit/System Testing

  1. Ignition OFF, disconnect the TV antenna module harness connector.
  2. Radio ON, test for B+ between terminal 20 and ground.
  3. If less than the specified value, test the circuit for a short to ground or open/high resistance..
  4. Test for less than 5 Ω between the ground circuit terminal 19 and ground.
  5. If greater than the specified range, test the circuit for an open/high resistance.
  6. If all circuits test normal, replace the TV antenna module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Television Antenna Module Replacement