LaCrosse FWD V6-3.0L (2010)
‹› If greater than the specified range, perform the appropriate test listed below:
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Serial data circuits with one control module, test the serial data circuit for a short to voltage. If the circuit tests normal, replace the control
module.
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Serial data circuits with 2 or more control modules, test each section of the serial data circuit for a short to voltage. If the circuits test normal,
replace the control module that causes the short to voltage when connected.
Testing the Serial Data Circuits for a Short to Ground
1. Ignition OFF, disconnect the appropriate harness connectors at the following components:
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All low speed serial data splice packs
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Any module or component between that may be between the splice packs
2. Test for infinite resistance between the DLC serial data circuit terminal 1 and ground.
‹› If not the specified value, repair the short to ground.
3. Ignition OFF for 60 seconds, test for greater than 100 ohm between each serial data circuit at the splice pack and ground.
‹› If less than the specified range, perform the appropriate test listed below:
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Serial data circuits with one control module, test the serial data circuit for a short to ground. If the circuit tests normal, replace the control
module.
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Serial data circuits with 2 or more control modules, test each section of the serial data circuit for a short to ground. If the circuits test normal,
replace the control module that causes the short to ground when connected.
Testing the Serial Data Circuit for an Open/High Resistance
1. If equipped with a second splice pack, ignition ON, verify the scan tool communicates with one or more control modules connected to the second
splice pack.
‹› If all control modules on the second splice pack do not communicate, test the serial data circuit between the first and second splice packs for
an open/high resistance. If the circuit tests normal, test the second splice pack for an open/high resistance. If the splice pack tests normal,
replace any module or component that may be between those two splice packs.
2. If equipped with a third splice pack, ignition ON, verify the scan tool communicates with one or more control modules connected to the third
splice pack.
‹› If all control modules on the third splice pack do not communicate, test the serial data circuit between the second and third splice packs for an
open/high resistance. If the circuit tests normal, test the third splice pack for an open/high resistance. If the splice pack tests normal, replace
any module or component that may be between the those two splice packs.
3. Ignition OFF, disconnect the splice pack containing the serial data circuits to the modules that are not communicating.
4. Install a 3 A fused jumper wire between the splice pack connector serial data input terminal and a low speed GMLAN serial data circuit that is not
communicating:
5. Ignition ON, verify the scan tool communicates with the control modules connected to the low speed GMLAN serial data circuit.
‹› If any control module does not communicate, test each section of the serial data circuit for an open/high resistance. If the circuits test normal,
replace the control module that does not communicate when connected.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Testing and Inspection/Diagnostic Trouble Code Tests and Associated Procedures/Verification Tests
and Procedures) after completing the repair.
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GMLAN Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/GMLAN Wiring Repairs)
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Control Module References (See: Testing and Inspection/Programming and Relearning) for module replacement, setup, and programming
