Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Circuit/System Testing
2009 Chevrolet Tahoe Base, 4.8 CSECTION Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 8 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.
- Ignition OFF, disconnect the harness connectors at the T1 Accessory DC/AC power inverter module.
- Test for less than 10 Ξ© between the ground circuit terminal 1 X2 and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Verify that a test lamp illuminates between the B+ circuit terminal 2 X2 and ground.
- If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
- Ignition ON, test for less than 1.0 V between the AC circuit terminals listed below and ground:
- Terminal 4 X1
- Terminal 6 X1
- If greater than the specified range, test the AC circuit for a short to voltage.
- Ignition OFF, test for infinite resistance between the AC circuit terminals listed below and ground:
- Terminal 4 X1
- Terminal 6 X1
- If less than the specified value, test the AC circuit for a short to ground.
- Disconnect the harness connector at the X81 accessory power receptacle - 110 V AC.
- Ignition ON, verify a test lamp illuminates between the control circuit terminal 4 and ground.
- If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
- Verify a test lamp does not illuminate between the signal terminal 1 and ground.
- If the test lamp illuminates, test the signal circuit for a short to voltage. If the circuit tests normal, replace the T1 Accessory DC/AC power inverter module.
- Connect a 3 A fused jumper between the control terminal 4 and the signal terminal 1.
- Ignition ON, verify that a test lamp illuminates between the T1 Accessory DC/AC power inverter module signal circuit terminal 2 X1 and ground.
- If the test lamp does not illuminate, test the signal circuit for a short to ground or an open/high resistance.
- Ignition OFF, connect the harness connectors at the T1 Accessory DC/AC power inverter module. Ignition ON, test for 110-120 V AC between the X81 accessory power receptacle - 110 V AC terminal 3 and 6.
- If not within the specified range, check both AC circuits for an open/high resistance. If all circuits test normal, replace the T1 Accessory DC/AC power inverter module.
- If all circuits test normal, replace the X81 accessory power receptacle - 110 V AC.
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.