Circuit/System Testing

2006 Chevrolet Chevy Express G2500, Van Cargo, 6.6 2SECTION Circuit/System Testing
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Power Seat Switch Circuit Test

  1. Disconnect the harness connector at the power seat switch.
  2. Verify that a test lamp illuminates between the ground circuit terminal B and B+.
    • If the test lamp does not illuminate, repair the ground circuit for an open/high resistance.
  3. Verify that a test lamp illuminates between the listed B+ circuit terminal and ground.
    • With AN3 terminal E
    • Without AN3 terminal D
    • If the test lamp does not illuminate, repair the B+ circuit for an open/high resistance or short to ground.
  4. If all circuits test normal, test or replace the power seat switch.

Lumbar Switch Circuit Test

  1. Disconnect the harness connector at the lumbar switch.
  2. Verify that a test lamp illuminates between the ground circuit terminal E and B+.
    • If the test lamp does not illuminate, repair the ground circuit for an open/high resistance.
  3. Verify that a test lamp illuminates between the B+ circuit terminal G and ground.
    • If the test lamp does not illuminate, repair the B+ circuit for an open/high resistance or short to ground.
  4. If all circuits test normal, test or replace the lumbar switch.

Seat Adjuster Circuit Test

  1. Ignition OFF, disconnect the harness connector at the seat adjuster assembly.
  2. Ignition OFF, test for less than 1.0 ohm between the affected control circuit terminal listed and ground.
    • Rear vertical terminal 1
    • Front vertical terminal 2
    • Horizontal terminal 3
    • If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the power seat switch.
  3. Ignition OFF, test for less than 1.0 ohm between the affected control circuit terminal listed and ground.
    • Rear vertical terminal 4
    • Front vertical terminal 5
    • Horizontal terminal 6
    • If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the power seat switch.
  4. Connect a test lamp between the affected control circuit terminals listed.
    • Rear vertical terminal 1 to terminal 4
    • Front vertical terminal 2 to terminal 5
    • Horizontal terminal 3 to terminal 6
  5. Operate the affected switch in both directions. The test lamp should turn ON when the switch is pressed in both directions.
    • If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, replace the power seat switch.
  6. If all circuits test normal, test or replace the seat adjuster.

Recliner Actuator Circuit Test

  1. Ignition OFF, disconnect the harness connector at the redline motor.
  2. Ignition OFF, test for less than 1.0 ohm between the control circuit terminal A and ground.
    • If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the power seat switch.
  3. Ignition OFF, test for less than 1.0 ohm between the control circuit terminal B and ground.
    • If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the power seat switch.
  4. Connect a test lamp between control circuit terminal A and control circuit terminal B.
  5. Operate the recline switch in both directions. The test lamp should turn ON when the switch is pressed in both directions.
    • If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, replace the power seat switch.
  6. If all circuits test normal, test or replace the recliner motor.

Lumbar Support Circuit Test

  1. Ignition OFF, disconnect the harness connector at the lumbar adjuster assembly.
  2. Ignition OFF, test for less than 1.0 ohm between the affected control circuit terminal listed and ground.
    • Vertical lumbar terminal A
    • Horizontal lumbar terminal C
    • If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace the lumbar switch.
  3. Ignition OFF, test for less than 1.0 ohm between the affected control circuit terminal listed and ground.
    • Vertical lumbar terminal B
    • Horizontal lumbar terminal D
    • If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace the lumbar switch.
  4. Connect a test lamp between affected control circuit terminals listed.
    • Vertical lumbar terminal A to terminal B
    • Horizontal lumbarterminal C to terminal D
  5. Operate the affected switch in both directions. The test lamp should turn ON when the switch is pressed in both directions.
    • If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, replace the lumbar switch.
  6. If all circuits test normal, test or replace the lumbar support.
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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

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