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Home >> Chevrolet >> 2013 >> Volt >> Repair and Diagnosis >> External Pages >> Different car >> Section 151 (Cellular System, Entertainment System, And Navigation System) >> Diagnostic Information and Procedures >> Radio Information Display Malfunction - DTC U0257 >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2012 Chevrolet Volt. However, it is still accessible from the selected car via links, so may be relevant.
  1. Vehicle OFF.
  2. Verify the video interface cable is properly connected at the P17 info display module X2 and A11 radio X5 connections and there is no damage to the cable or connections.
    • If connection problems or cable damage is noted. 

      Perform the appropriate repair or replacement to correct any issues.

    • If no issues are found with the video interface cable. 
  3. Disconnect the X1 harness connector at the P17 info display module.
  4. Test for less than 10 Ω between the ground circuit terminal 2 and ground.
    • If 10 Ω or greater 
    1. Vehicle 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 
  5. Test for less than 20 Ω between the data shield circuit terminal 7 and ground.
    • If 20 Ω or greater 
    1. Vehicle OFF, disconnect the X1 connector at the A11 radio.
    2. Test for less than 2 Ω in the data shield 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 less than 20 Ω 
  6. 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. Vehicle 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. Vehicle 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. 
  7. Vehicle in Service Mode, radio ON.
  8. Verify that a test lamp illuminates between the control circuit terminal 6 and ground.
    • If the test lamp does not illuminate. 
    1. Vehicle OFF, disconnect the X1 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 the test lamp illuminates. 
  9. Test for 2-3 V between the data circuit terminals listed below and ground.
    • terminal 4
    • terminal 8
    • If less than 2 V 
    1. Vehicle OFF, disconnect the X1 harness connector at the A11 radio.
    2. Test for infinite resistance between the data 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 data 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 3 V 
    1. Vehicle OFF, disconnect the X1 harness connector at the A11 radio. Vehicle in Service Mode.
    2. Test for less than 1 V between the signal 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 2-3 V 
  10. Vehicle in Service Mode.
  11. Test for less than 1 V between the control circuit terminal 5 and ground.
    • If greater than 1 V 
    1. Vehicle OFF, disconnect the X4 harness connector at the A11 radio. Vehicle in Service Mode.
    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 less than 1 V 
  12. Vehicle OFF, disconnect the X4 harness connector at the A11 radio.
  13. Test for infinite resistance between the P17 info display module control circuit terminal 5 X1 and ground.
    • If less than infinite resistance, 

      Repair the short to ground on the circuit.

    • If infinite resistance 
  14. Test for less than 2 Ω between the P17 info display module control circuit terminal 5 X1 and the A11 radio control circuit terminal 10 X4.
    • If 2 Ω or greater 

      Repair the open/high resistance in the circuit.

    • If less than 2 Ω. 
  15. Replace the video interface cable.
  16. Connect all harness connectors.
  17. Vehicle in Service Mode, radio ON.
  18. Verify the P17 info display module turns on and information is shown on the display.
    • If the P17 info display module does not turn on, or information is not shown in the display. 
    1. Replace the P17 information display module.
    2. Vehicle in Service Mode, radio ON.
    3. Verify the P17 info display module turns on and information is shown on the display.
      • If the information display malfunctions, replace the A11 radio.
      • If the info display module turns on and information is shown on the display.
    4. All OK.
    • If the info display module turns on and information is shown on the display. 
  19. All OK
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