LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Buick >> 2017 >> Verano Base, Gas >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Infotainment >> Cellular System, Entertainment System, And Navigation System >> Diagnostic Information and Procedures >> DTC B2625: Display Dimming Pulse Width Modulation (PWM) Output >> Circuit/System Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit/System Testing

  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.
scientia non olet · About LEMON Manuals