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Home >> Buick >> 2016 >> Verano Base, Gas >> Repair and Diagnosis >> External Pages >> Different car >> Section 75 (Cellular System, Entertainment System, And Navigation System) >> Diagnostic Information and Procedures >> DTC B2625: Display Dimming Pulse Width Modulation (PWM) Output Circuit >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2015 Buick Verano. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the X1 harness connector at the P17 info display module.
  2. Test for less than 10 Ω between the ground circuit terminal 2 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF.
    2. Test for less than 2 Ω in the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
    • If less than 10 Ω 
  3. Verify that a test lamp illuminates between the B+ circuit terminal 1 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Ignition OFF.
    2. Test for less than 2 Ω in the B+ circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, refer to Power Mode Mismatch .
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Ignition OFF.
    2. Test for infinite resistance between the B+ circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the P17 info display module.
    • If the test lamp illuminates. 
  4. Ignition ON, radio ON.
  5. Verify that a test lamp illuminates between the control circuit terminal 6 and ground.
    • If the test lamp does not illuminate. 
    1. Ignition OFF, disconnect the X1 harness connector at the A11 radio.
    2. Test for infinite resistance between the remote enable circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2 Ω in the remote enable circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the A11 radio.
    • If the test lamp illuminates. 
  6. Ignition ON, lights ON, set the I/P dimming switch to full bright.
  7. Test for 1-1.5 V between the dimming control circuit terminal 3 and ground.
    • If less than 1 V 
    1. Ignition OFF, disconnect the X2 harness connector at the A11 radio.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the A11 radio.
    • If greater than 1.5 V 
    1. Ignition OFF, disconnect the X2 harness connector at the A11 radio. Ignition ON.
    2. Test for less than 1 V between the control circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the A11 radio.
    • If between 1-1.5 V 
  8. Verify the voltage increases steadily to 6-7 V at full dim while using the I/P dimming switch to decrease the dimming level.
    • If less than 6 V 
    1. Ignition OFF, disconnect the X2 harness connector at the A11 radio.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the A11 radio.
    • If greater than 7 V 
    1. Ignition OFF, disconnect the X2 harness connector at the A11 radio. Ignition ON.
    2. Test for less than 1 V between the control circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the A11 radio.
    • If between 6-7 V 
  9. Replace the P17 info display module.
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