Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2011 GMC Yukon XL, 2011 GMC Yukon, 2011 Chevrolet Tahoe, 2011 Chevrolet Suburban, and 2011 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- Key OFF. Disconnect the X1 connector at the transfer case shift control switch (TCSCS). Install EL-49742 harness.
- Key ON (Ignition C), engine OFF.
- Using the L-BU probes J 35616-64B, test for 4.86-5.25 V between the 5-volt reference circuit, TCSCS X1 pin 11, and the ground terminal of EL-49742
harness, black terminal.
- If the voltage is less than the specified value, test the 5-volt reference circuit for an open/high resistance or short to ground condition. If all circuits and connections test normal, test the TCCM for proper operation.
- If the voltage is greater than the specified value, test the 5-volt reference circuit for a short to voltage. If all circuits and connections test normal, test the TCCM for proper operation.
- Using the L-BU probes J 35616-64B, test for 4.86-5.25 V between the 5-volt reference circuit, TCSCS X1 pin 11, and the switch signal circuit TCSCS X1 pin 12.
- If the voltage is less than the specified value, test the switch signal circuit for an open/high resistance, short to ground or short together. If all circuits and connections test normal, test the TCCM for proper operation.
- If the voltage is greater than the specified value, test the switch signal circuit for a short to voltage. If all circuits and connections test normal, test the TCCM for proper operation.
- Using the L-BU probes J 35616-64B, test for greater than 500 Ω between the 5-volt reference circuit, TCSCS X1 pin 11, and all other pins of the TCSCS X1.
- If the resistance is less than the specified value, test the affected circuits for short together condition. If all circuits and connections test normal, test the TCCM for proper operation.
- Using the L-BU probes J 35616-64B, test for greater than 500 Ω between the switch signal circuit TCSCS X1 pin 12, and all other pins of the TCSCS X1.
- If the resistance is less than the specified value, test the affected circuits for short together condition. If all circuits and connections test normal, test the TCCM for proper operation.
- Test the TCSCS for proper operation.
NOTE:
When test probing harness terminals, it is imperative to use the proper test probe from the most current version of the J 35616 GM terminal test kit. Use of an improper test probe may deform the terminal, resulting in intermittent open conditions.