LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2018 >> Equinox L >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Headlights >> Lighting System - Diagnostic Information And Procedures >> Diagnostic Information And Procedures >> Turn Signal Lamps And/Or Indicators Malfunction >> Circuit/System Testing

Circuit/System Testing

Turn Signal/Multifunction Switch Malfunction

  1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the S78 Turn Signal/Multifunction Switch. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 5 Ω between the ground circuit terminal 3 and ground.
    • If 5 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.
    • Go to next step: If less than 5 Ω 
  3. Ignition ON.
  4. Verify the scan tool Left Turn Signal Switch parameter is Inactive.
    • If not Inactive 
    1. Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module.
    2. Test for infinite resistance between the signal circuit terminal 1 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K9 Body Control Module.
    • Go to next step: If Inactive 
  5. Install a 3 A fused jumper wire between the signal circuit terminal 1 and ground.
  6. Verify the scan tool Left Turn Signal Switch parameter is Active.
    • If not Active 
    1. Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module, ignition ON.
    2. Test for less than 1 V between the signal circuit terminal 1 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V
    3. Test for less than 2 Ω in the signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 Body Control Module.
    • Go to next step: If Active 
  7. Verify the scan tool Right Turn Signal Switch parameter is Inactive.
    • If not Inactive 
    1. Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module.
    2. Test for infinite resistance between the signal circuit terminal 2 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K9 Body Control Module.
    • Go to next step: If Inactive 
  8. Install a 3 A fused jumper wire between the signal circuit terminal 2 and ground.
  9. Verify the scan tool Right Turn Signal Switch parameter is Active.
    • If not Active 
    1. Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module, ignition ON.
    2. Test for less than 1 V between the signal circuit terminal 2 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V
    3. Test for less than 2 Ω in the signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 Body Control Module.
    • Go to next step: If Active 
  10. Test or replace the S78 Turn Signal/Multifunction Switch.

Turn Signal Lamps Malfunction

  1. Ignition OFF, exterior lamps OFF, disconnect the harness connector at the appropriate E4 Turn Signal Lamp listed below.
    • E4LF Turn Signal Lamp - Left Front
    • E4Y Turn Signal Repeater Lamp - Left
    • E5LE Tail/Stop Lamp - Left Outer (Z88/X88-UGE)
    • E42L Tail Lamp Assembly - Left (X88+UGE)
    • E4RF Turn Signal Lamp - Right Front
    • E4Z Turn Signal Repeater Lamp - Right
    • E5RE Tail/Stop Lamp - Right Outer (Z88/X88-UGE)
    • E42R Tail Lamp Assembly - Right (X88+UGE)
  2. Test for less than 10 Ω between the appropriate ground circuit terminal listed below and ground.
    • E4LF Turn Signal Lamp - Left Front socket terminal
    • E4Y Turn Signal Repeater Lamp - Left socket terminal
    • E5LE Tail/Stop Lamp - Left Outer socket terminal (Z88/X88-UGE)
    • E42L Tail Lamp Assembly - Left terminal 4 (X88+UGE)
    • E4RF Turn Signal Lamp - Right Front socket terminal
    • E4Z Turn Signal Repeater Lamp - Right socket terminal
    • E5RE Tail/Stop Lamp - Right Outer socket terminal (Z88/X88-UGE)
    • E42R Tail Lamp Assembly - Right terminal 4 (X88+UGE)
    • 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.
    • Go to next step: If less than 10 Ω 
  3. Connect a test lamp between the appropriate control circuit terminal listed below and ground, ignition ON.
    • E4LF Turn Signal Lamp - Left Front socket terminal
    • E4Y Turn Signal Repeater Lamp - Left socket terminal
    • E5LE Tail/Stop Lamp - Left Outer socket terminal (Z88/X88-UGE)
    • E42L Tail Lamp Assembly - Left terminal 4 (X88+UGE)
    • E4RF Turn Signal Lamp - Right Front socket terminal
    • E4Z Turn Signal Repeater Lamp - Right socket terminal
    • E5RE Tail/Stop Lamp - Right Outer socket terminal (Z88/X88-UGE)
    • E42R Tail Lamp Assembly - Right terminal 4 (X88+UGE)
  4. Verify the test lamp turns ON and OFF when commanding the appropriate Turn Signal Lamp ON and OFF with a scan tool.
    • If the test lamp is always OFF 
    1. Ignition OFF, disconnect the appropriate harness connector listed below at the K9 Body Control Module.
      • X5 left front and right rear turn signals
      • X4 right front and left rear turn signals
    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 K9 Body Control Module.
    • If the test lamp is always ON 
    1. Ignition OFF, disconnect the appropriate harness connector listed below at the K9 Body Control Module, ignition ON.
      • X5 left front and right rear turn signals
      • X4 right front and left rear turn signals
    2. Test for less than 1 V between the control circuit terminal and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K9 Body Control Module.
    • Go to next step: If the test lamp turns ON and OFF 
  5. Test or replace the appropriate turn signal lamp.

Tail/Stop Lamp Outage Detection Malfunction

  1. Ignition OFF, disconnect the harness connector at the appropriate E42 Tail Lamp Assembly, ignition ON.
  2. Test for B+ between the signal circuit terminal 3 and ground.
    • If not B+ 
    1. Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module.
    2. Test for infinite resistance between the signal 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 signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 Body Control Module.
    • Go to next step: If B+ 
  3. Verify a test lamp does not illuminate between the signal circuit terminal 3 and ground.
    • If the test lamp illuminates 
    1. Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module, ignition ON.
    2. Test for less than 1 V between the signal circuit terminal and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K9 Body Control Module.
    • Go to next step: If the test lamp does not illuminate 
  4. Test or replace the E5 Tail/Stop Lamp - Outer.

Turn Signal Indicators Malfunction

  1. Ignition ON.
  2. Verify the left and right turn signal indicators turn ON and OFF while commanding the All Indicators Test ON and OFF with a scan tool.
    • If the left or right turn signal indictors are always OFF or remain ON 

      Replace the P16 Instrument Cluster.

    • Go to next step: If the left and right turn signal indictors turn ON and OFF 
  3. Replace the K9 Body Control Module.
scientia non olet · About LEMON Manuals