LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2021 >> Malibu LT >> Repair and Diagnosis >> Engine Mechanical >> Starter >> 12 V Starting And Charging - Diagnostic Information And Procedures (1 Of 2) >> Diagnostic Information and Procedures >> DTC P3052, P3054, or P3056 >> Circuit/System Testing - T19 Power Supply Transformer Input/Output Circuit Test

Circuit/System Testing - T19 Power Supply Transformer Input/Output Circuit Test

NOTE:

Circuit/System Verification must be performed before proceeding with Circuit/System Testing.

    NOTE:

    Do not replace the T19 Power Supply control module if you cannot reproduce the codes during a drive cycle.

  1. Ignition/Vehicle & All vehicle systems - Off
  2. Disconnect the electrical connector: T19 Power Supply Transformer
  3. Test for less than 2 ohms between the test points:
    • Ground circuit terminal 7 @ T19 Power Supply Transformer & Ground
    • Ground circuit terminal 12 @ T19 Power Supply Transformer & Ground
    • If 2 ohms or greater 
    1. Disconnect the appropriate ground connection:
    2. Test for less than 0.5 ohms between the test points: Each ground circuit terminal @ T19 Power Supply Transformer & The other end of the circuit
      • If 0.5 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 0.5 ohms - Repair the open/high resistance in the ground connection.
    • Go to next step: If less than 2 ohms 
  4. Verify a test lamp turns On between the test points: B+ circuit terminal 8 @ T19 Power Supply Transformer & Ground
    • If the test lamp does not turn On and the circuit fuse is OK 
    1. Ignition/Vehicle - Off & Remove - Test lamp
    2. Test for less than 2 ohms between the test points: B+ circuit terminal 8 @ T19 Power Supply Transformer & Output terminal @ Fuse
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Verify the fuse is OK and there is voltage at the fuse.
    • If the test lamp does not turn On and the circuit fuse is open 
    1. Ignition/Vehicle - Off & Remove - Test lamp
    2. Test for infinite resistance between the test points: B+ circuit terminal 8 @ T19 Power Supply Transformer & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance - Replace the component: T19 Power Supply Transformer
    • Go to next step: If the test lamp turns On 
  5. Ignition - On/Vehicle - In Service Mode
  6. Verify a test lamp turns On between the test points: Ignition circuit terminal 6 @ T19 Power Supply Transformer & Ground
    • If the test lamp does not turn On and the circuit fuse is OK 
    1. Ignition/Vehicle - Off & Remove - Test lamp
    2. Test for less than 2 ohms between the test points: Ignition circuit terminal 6 @ T19 Power Supply Transformer & KR73 Ignition Main Relay
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Verify the fuse is OK and there is voltage at the fuse.
    • If the test lamp does not turn On and the circuit fuse is open 
    1. Ignition/Vehicle - Off & Remove - Test lamp
    2. Test for infinite resistance between the test points: Ignition circuit terminal 6 @ T19 Power Supply Transformer & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance - Replace the component: T19 Power Supply Transformer
    • Go to next step: If the test lamp turns On 
  7. Ignition Off
  8. Verify a test lamp does not turn On between the test points: Ignition circuit terminal 6 @ T19 Power Supply Transformer & Ground
    • If the test lamp turns On 

      Repair the short to voltage on the circuit.

    • Go to next step: If the test lamp does not turn On 
  9. Ignition - On/Vehicle - In Service Mode
  10. Verify a test lamp does not turn On between terminal 9 and ground.
    • If the Testlamp Turns On 

      Repair the short to voltage on circuit 2173.

    • Go to next step: if the test lamp does not turn On 
  11. Remove all appropriate fuses supplied by circuit 2173.
  12. Test for infinite resistance between Terminal 9 at the T19 Power Supply Transformer and ground.
      NOTE:

      A less than infinite reading can be caused by component circuits being shorted to another component within the harness or a slight chafe to grounds preventing a fuse to open.

    • If less than infinite 

      Repair the short to ground on the circuit.

    • Go to next step: If infinite resistance 
  13. Replace the T19 Power Supply Transformer.
scientia non olet · About LEMON Manuals