Sierra 3500 Denali 2WD V8-6.0L (2011)
Interior Backlighting Malfunction (w/AN3) (See: Lighting and Horns/Testing and Inspection/Interior Backlighting Malfunction (w/AN3))Interior
Backlighting Malfunction (w/o AN3) (See: Lighting and Horns/Testing and Inspection/Interior Backlighting Malfunction (w/o AN3)).
3. Ignition OFF, connect the harness connector at the heated seat switch.
4. Disconnect the X3, X4 harness connectors at the heated seat module.
5. Ignition ON, connect a test lamp between the control circuits listed below and ground. The appropriate indicator should turn ON and OFF when
the test lamp is connected and disconnected.
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Driver seat high heat indicator terminal 5 X3
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Driver seat medium heat indicator terminal 16 X4
*
Driver seat low heat indicator terminal 4 X3
*
Driver seat back and cushion heat indicator terminal 17 X4
*
Driver seat back heat indicator terminal 15 X4
*
Passenger seat high heat indicator terminal 10 X3
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Passenger seat medium heat indicator terminal 6 X4
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Passenger seat low heat indicator terminal 9 X3
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Passenger seat back and cushion heat indicator terminal 7 X4
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Passenger seat back heat indicator terminal 18 X4
‹› If the test lamp is always ON, test the appropriate control circuit for a short to ground. If the circuit tests normal, test or replace the heated seat
switch.
‹› If the test lamp is always OFF, test the appropriate control circuit for a short to voltage or an open/high resistance. If the circuit tests normal,
test or replace the heated seat switch.
6. If all circuits test normal, replace the HSM.
Component Testing
Heated Seat Switch
1. Ignition OFF, disconnect the harness connector at the heated seat switch switch.
2. Test for infinite resistance between the signal terminal 4 and the ground terminal 7 with the back and cushion switch in the open position.
‹› If not the specified value, replace the heated seat switch switch.
3. Test for infinite resistance between the signal terminal 5 and the ground terminal 7 with the back only switch in the open position.
‹› If not the specified value, replace the heated seat switch switch.
4. Test for less than 5 Ohms between the signal terminal 4 and the ground terminal 7 with the back and cushion switch in the closed position.
‹› If greater than the specified value, replace the heated seat switch.
5. Test for less than 5 Ohms between the signal terminal 5 and the ground terminal 7 with the back only switch in the closed position.
‹› If greater than the specified value, replace the heated seat switch.
6. Install a 3 A fused jumper wire between the control terminal 2 and B+.
7. Connect a test lamp between the control circuits listed below and ground. The selected indicator should illuminate.
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Back and cushion heat indicator terminal 1
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Low heat indicator terminal 6
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Medium heat indicator terminal 8
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Back only heat indicator terminal 9
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High heat indicator terminal 10
‹› If any indicator does not illuminate, replace the heated seat switch.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Diagnostic Trouble
Code Tests and Associated Procedures/Verification Tests and Procedures) after completing the diagnostic procedure.
Control Module References (See: Testing and Inspection/Programming and Relearning/Control Module References)for heated seat control module
replacement, setup, and programming
