Circuit/System Testing
WARNING: This page is about a different car, the 2007 GMC Sierra, 2007 GMC Cab & Chassis Sierra, 2007 Chevrolet Silverado, and 2007 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the harness connector at the TC vane control solenoid.
- Connect the J 34730-405 between the high control circuit terminal A and the low control circuit terminal B.
- Engine running, engine coolant temperature (ECT) sensor 1 must be less than 70°C (158°F). Command the TC Vane Pos. Ctrl. Solenoid ON and OFF with a scan tool. The test lamp should illuminate and change from bright to dim when changing between the commanded states.
- If the test lamp does not illuminate, test the low control circuit terminal B for an open/high resistance or a short to voltage. If the circuit tests normal, test the high control circuit terminal A for a short to ground or an open/high resistance. If the circuits test normal, replace the ECM.
- If the test lamp remains illuminated, test the low control circuit terminal B for a short to ground.
- Ignition OFF, test for a resistance between 2-7 ohms across the terminals of the TC vane control solenoid.
- If the resistance is not within the specified range, replace the TC vane position solenoid.
- Test for infinite resistance between each terminal and the TC vane control solenoid housing.
- If less than infinite resistance, replace the TC vane control solenoid.
- If all circuits test normal, replace the TC control vane control solenoid.
IMPORTANT:
When the engine coolant temperature is less than 70°C (158°F), the test lamp will change brightness when commanded with a scan tool. When the engine coolant temperatures are above 70°C (158°F), the test lamp will flash ON and OFF without commands from a scan tool.