Circuit/System Testing
WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
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-Approved Terminal Test Kit. Use of an improper test probe may deform the terminal, resulting in intermittent open conditions.
- Key OFF. Disconnect the X3 harness connector at the TCCM.
- Measure the voltage at the battery. The voltage should be above 12.0 V.
- If the voltage is below 12.0 V, ensure that the battery is fully charged and working properly. Refer to Battery Inspection/Test , Battery Electrical Drain/Parasitic Load Test and Battery Common Causes of Malfunction .
- Install harness EL-49742. Test for B+ (+0.0/-0.5 V) between the 12 volt terminal (red) and the ground terminal (black) of harness EL-49742.
- If the voltage is less than the specified value, a vehicle wide issue is indicated. Inspect the battery positive circuit wire routing for chafed wires or damaged inline harness connectors that could cause unexpected voltage drops.
- Using the purple probe J 35616-4A, test for B+ (+0.0/-0.5 V) between the battery positive voltage circuit, TCCM X3 pin C, and the ground terminal of harness EL-49742, black terminal.
- If the voltage is less than the specified range, test the battery positive voltage circuit for an open/high resistance or short to ground.
- Using the purple probe J 35616-4A, test for B+ (+0.0/-0.5 V) between the battery positive voltage circuit, TCCM X3 pin C, and the ground circuit TCCM X3 pin D.
- If the voltage is less than the specified range, test the ground circuit for an open/high resistance, short to ground or short together condition.