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Circuit/System Testing

WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.

Turn Signal Multifunction Switch - Malfunction

    NOTE:

    It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.

  1. Ignition/Vehicle & All vehicle systems - Off
  2. Disconnect the electrical connector:S78 Turn Signal/Multifunction Switch
  3. Test for less than 15 ohms between the test points:Ground circuit terminal 3 & Ground
    • If 15 ohms or greater 
    1. Test for less than 2 ohms between the test points:Ground circuit terminal 3 & Ground terminal
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Repair the open/high resistance in the ground connection.
    • Go to next step: If less than 15 ohms 
  4. Ignition - On / Vehicle - In Service Mode
  5. Verify the scan tool parameter:Left Turn Signal Switch = Inactive
    • If not the specified state 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector:X3 @ K9 Body Control Module
    3. Test for infinite resistance between the test points:Signal circuit terminal 1 @ Component harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance - Replace the component:K9 Body Control Module
    • Go to next step: If the specified state 
  6. Connect a 3 A fused jumper wire between the test points:Signal circuit terminal 1 @ Component harness & Ground
  7. Verify the scan tool parameter:Left Turn Signal Switch = Active
    • If not the specified state 
    1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
    2. Disconnect the electrical connector:X3 @ K9 Body Control Module
    3. Ignition - On / Vehicle - In Service Mode
    4. Test for less than 1 V between the test points:Signal circuit terminal 1 @ Component harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • Go to next step: If less than 1 V
    5. Ignition/Vehicle - Off
    6. Test for less than 2 ohms between the test points:Signal circuit terminal 1 @ Component harness & Signal circuit terminal 12 X3 @ Control module harness
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Replace the component:K9 Body Control Module
    • Go to next step: If the specified state 
  8. Verify the scan tool parameter:Right Turn Signal Switch = Inactive
    • If not the specified state 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector:X3 @ K9 Body Control Module
    3. Test for infinite resistance between the test points:Signal circuit terminal 1 @ Component harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance - Replace the component:K9 Body Control Module
      • Go to next step: If the specified state 
  9. Connect a 3 A fused jumper wire between the test points:Signal circuit terminal 2 @ Component harness & Ground
  10. Verify the scan tool parameter:Right Turn Signal Switch = Active
    • If not the specified state 
  11. Ignition/Vehicle - Off & Remove - Jumper wire(s)
  12. Disconnect the electrical connector:X3 @ K9 Body Control Module
  13. Ignition - On / Vehicle - In Service Mode
  14. Test for less than 1 V between the test points:Signal circuit terminal 2 @ Component harness & Ground
    • If 1 V or greater - Repair the short to voltage on the circuit.
    • Go to next step: If less than 1 V
  15. Ignition/Vehicle - Off
  16. Test for less than 2 ohms between the test points:Signal circuit terminal 2 @ Component harness @ Signal circuit terminal 24 x3 @ Control module harness
    • If 2 ohms or greater - Repair the open/high resistance in the circuit.
    • If less than 2 ohms - Replace the component:K9 Body Control Module
    • Go to next step: If the specified state 
  17. Test or replace the component:S78 Turn Signal/Multifunction Switch

Turn Signal Lamps - Malfunction

    NOTE:

    It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.

  1. Ignition/Vehicle & All vehicle systems - Off
  2. Disconnect the appropriate component:
    • A9A Outside Rearview Mirror - Driver { With DWK }
    • A9B Outside Rearview Mirror - Passenger { With DWK }
    • E4LF Turn Signal Lamp - Left Front
    • E4RF Turn Signal Lamp - Right Front
    • E4LR Turn Signal Lamp - Left Rear { Without UGE }
    • E42L Tail Lamp Assembly - Left { With UGE }
    • E4RR Turn Signal Lamp - Right Rear { Without UGE }
    • E42R Tail Lamp Assembly - Right { With UGE }
  3. Test for less than 15 ohms between the test points:
    • A9A Outside Rearview Mirror - Driver Terminal 5 & Ground { With DWK }
    • A9B Outside Rearview Mirror - Passenger Terminal 5 & Ground { With DWK }
    • E4LF Turn Signal Lamp - Left Front Terminal B & Ground
    • E4RF Turn Signal Lamp - Right Front Terminal B & Ground
    • E4LR Turn Signal Lamp - Left Rear Terminal B & Ground { Without UGE }
    • E42L Tail Lamp Assembly - Left Terminal 1 & Ground { With UGE }
    • E4RR Turn Signal Lamp - Right Rear Terminal B & Ground { Without UGE }
    • E42R Tail Lamp Assembly - Right Terminal 1 & Ground { With UGE }
    • If 15 ohms or greater 
    1. Ignition/Vehicle - Off
    2. Test for less than 2 ohms between the test points:
      • A9A Outside Rearview Mirror - Driver Terminal 5 & Ground terminal { With DWK }
      • A9B Outside Rearview Mirror - Passenger Terminal 5 & Ground terminal { With DWK }
      • E4LF Turn Signal Lamp - Left Front Terminal B & Ground terminal
      • E4RF Turn Signal Lamp - Right Front Terminal B & Ground terminal
      • E4LR Turn Signal Lamp - Left Rear Terminal B & Ground terminal { Without UGE }
      • E42L Tail Lamp Assembly - Left Terminal 1 & Ground terminal { With UGE }
      • E4RR Turn Signal Lamp - Right Rear Terminal B & Ground terminal { Without UGE }
      • E42R Tail Lamp Assembly - Right Terminal 1 & Ground terminal { With UGE }
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Repair the open/high resistance in the ground connection.
    • Go to next step: If less than 15 ohms 
  4. Ignition - On / Vehicle - In Service Mode
  5. Connect a test lamp between the test points:
    • A9A Outside Rearview Mirror - Driver Terminal 13 & Ground { With DWK }
    • A9B Outside Rearview Mirror - Passenger Terminal 13 & Ground { With DWK }
    • E4LF Turn Signal Lamp - Left Front Terminal A & Ground
    • E4RF Turn Signal Lamp - Right Front Terminal A & Ground
    • E4LR Turn Signal Lamp - Left Rear Terminal A & Ground { Without UGE }
    • E42L Tail Lamp Assembly - Left Terminal 2 & Ground { With UGE }
    • E4RR Turn Signal Lamp - Right Rear Terminal A & Ground { Without UGE }
    • E42R Tail Lamp Assembly - Right Terminal 2 & Ground { With UGE }
  6. Scan Tool Device Control - Turn Signal Lamps - On and Off
  7. Verify the test lamp turns On and Off.
    • If the test lamp is always Off 
    1. Ignition/Vehicle - Off & Remove - Test lamp
    2. Disconnect the appropriate electrical connector:
      • X5 @ K9 Body Control Module
      • X4 @ K9 Body Control Module
    1. Test for infinite resistance between the test points:
      • A9A Outside Rearview Mirror - Driver Terminal 13 & Ground { With DWK }
      • A9B Outside Rearview Mirror - Passenger Terminal 13 & Ground { With DWK }
      • E4LF Turn Signal Lamp - Left Front Terminal A & Ground
      • E4RF Turn Signal Lamp - Right Front Terminal A & Ground
      • E4LR Turn Signal Lamp - Left Rear Terminal A & Ground { Without UGE }
      • E42L Tail Lamp Assembly - Left Terminal 2 & Ground { With UGE }
      • E4RR Turn Signal Lamp - Right Rear Terminal A & Ground { Without UGE }
      • E42R Tail Lamp Assembly - Right Terminal 2 & Ground { With UGE }
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    2. Test for less than 2 ohms between the test points:
      • A9A Outside Rearview Mirror - Driver Terminal 13 & The other end of the circuit { With DWK }
      • A9B Outside Rearview Mirror - Passenger Terminal 13 & The other end of the circuit { With DWK }
      • E4LF Turn Signal Lamp - Left Front Terminal A & The other end of the circuit
      • E4RF Turn Signal Lamp - Right Front Terminal A & The other end of the circuit
      • E4LR Turn Signal Lamp - Left Rear Terminal A & The other end of the circuit { Without UGE }
      • E42L Tail Lamp Assembly - Left Terminal 2 & The other end of the circuit { With UGE }
      • E4RR Turn Signal Lamp - Right Rear Terminal A & The other end of the circuit { Without UGE }
      • E42R Tail Lamp Assembly - Right Terminal 2 & The other end of the circuit { With UGE }
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Replace the component:K9 Body Control Module
    • If the test lamp is always On 
    1. Ignition/Vehicle - Off & Remove - Test lamp
    2. Disconnect the appropriate electrical connector:
      • X5 @ K9 Body Control Module
      • X4 @ K9 Body Control Module
    3. Ignition - On / Vehicle - In Service Mode
    4. Test for less than 1 V between the test points:
      • A9A Outside Rearview Mirror - Driver Terminal 13 & Ground { With DWK }
      • A9B Outside Rearview Mirror - Passenger Terminal 13 & Ground { With DWK }
      • E4LF Turn Signal Lamp - Left Front Terminal A & Ground
      • E4RF Turn Signal Lamp - Right Front Terminal A & Ground
      • E4LR Turn Signal Lamp - Left Rear Terminal A & Ground { Without UGE }
      • E42L Tail Lamp Assembly - Left Terminal 2 & Ground { With UGE }
      • E4RR Turn Signal Lamp - Right Rear Terminal A & Ground { Without UGE }
      • E42R Tail Lamp Assembly - Right Terminal 2 & Ground { With UGE }
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • If less than 1 V - Replace the component:K9 Body Control Module
    • Go to next step: If the test lamp turns On and Off 
  8. Replace the appropriate component:
    • A9A Outside Rearview Mirror - Driver { With DWK }
    • A9B Outside Rearview Mirror - Passenger { With DWK }
    • E4LF Turn Signal Lamp - Left Front
    • E4RF Turn Signal Lamp - Right Front
    • E4LR Turn Signal Lamp - Left Rear { Without UGE }
    • E42L Tail Lamp Assembly - Left { With UGE }
    • E4RR Turn Signal Lamp - Right Rear { Without UGE }
    • E42R Tail Lamp Assembly - Right { With UGE }

Turn Signal Indicators - Malfunction

  1. Ignition - On / Vehicle - In Service Mode
  2. Verify the component activates:Left and Right - Turn Signal Indicators - Scan Tool Control Functions - All Indicators Command = On
    • If the component does not work as specified 

      Replace the component:P16 Instrument Cluster

    • Go to next step: If the component works as specified 
  3. Replace the component:K9 Body Control Module
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