Circuit/System Testing
WARNING: This page is about a different car, the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- Disconnect the AT inline 20-way connector. Install the J 44152
jumper harness (20 Pins), on the engine side of the AT inline 20-way connector. See Special Tools
. Using the J 35616
GM-approved terminal test kit, connect a test lamp between the affected control circuit and ground. Turn ON the ignition with the engine OFF. The test lamp should be OFF.
- If the test lamp is ON, test the affected control circuit for a short to voltage between the Fuse Block-Underhood and the AT inline 20-way connector.
- Disconnect the J 44152
from the engine harness. See Special Tools
. Connect the J 44152
to the transmission side of the AT inline 20-way connector. See Special Tools
. Using theJ 35616
, measure the resistance between the affected control circuit and the ignition 1 voltage circuit. Resistance should be between 19-31 ohms for the 1-2 SS and the 2-3 SS. Resistance should be between 10-15 ohms for the TCC PWM solenoid valve.
- If the resistance is less than the specified value, test for a short to the ignition 1 voltage circuit or a faulty solenoid.
- Using the J 35616
, measure the resistance between the affected control circuit and all other circuits in the J 44152
except the ignition 1 voltage circuit and the other control circuits. See Special Tools
. Resistance should be greater than 250K ohms.
- If resistance is less than 250K ohms, test the control circuit for a short to another circuit.