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.
2009 Cadillac Escalade EXTFACTORY OEM SERVICE PROCEDURE
Section 148 (Data Communication System)
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including 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.
- Specifications
- Schematic and Routing Diagrams
- Diagnostic Information and Procedures
- Diagnostic Code Index
- Diagnostic Starting Point - Data Communications
- DTC B1000
- DTC B1001
- DTC B137A
- DTC B137B
- Diagnostic Instructions
- DTC Descriptors
- Diagnostic Fault Information
- Circuit/System Description
- Conditions for Running the DTC
- Conditions for Setting the DTC
- Action Taken When the DTC Sets
- Conditions for Clearing the DTC
- Reference Information
- Circuit/System Verification
- Circuit/System Testing
- Repair Procedures
- DTC C0550
- DTC U0020
- DTC U0073 or U2100
- DTC U0074
- DTC U0100 - U0299 (Hp2)
- Diagnostic Instructions
- DTC Descriptors
- Diagnostic Fault Information
- Circuit/System Description
- Conditions for Running the DTC
- Conditions for Setting the DTC
- Action Taken When the DTC Sets
- Conditions for Clearing the DTC
- Diagnostic Aids
- Reference Information
- Circuit/System Verification
- Circuit/System Testing
- Repair Procedures
- DTC U0100 - U0299 (Except HP2)
- Diagnostic Instructions
- DTC Descriptors
- Diagnostic Fault Information
- Circuit/System Description
- Conditions for Running the DTC
- Conditions for Setting the DTC
- Action Taken When the DTC Sets
- Conditions for Clearing the DTC
- Diagnostic Aids
- Reference Information
- Circuit/System Verification
- Circuit/System Testing
- Repair Procedures
- DTC C126C, C126D, C12E3, or U180F
- DTC U180F
- DTC U1812
- Diagnostic Instructions
- DTC Descriptors
- Diagnostic Fault Information
- Circuit/System Description
- Conditions for Running the DTC
- Conditions for Setting the DTC
- Action Taken When the DTC Sets
- Conditions for Clearing the DTC
- Diagnostic Aids
- Reference Information
- Circuit/System Verification
- Circuit/System Testing
- Repair Procedures
- DTC U1813
- DTC U1814
- DTC U1815
- Diagnostic Instructions
- DTC Descriptor
- Diagnostic Fault Information
- Circuit/System Description
- Conditions for Running the DTC
- Conditions for Setting the DTC
- Action Taken When the DTC Sets
- Conditions for Clearing the DTC
- Diagnostic Aids
- Reference Information
- Circuit/System Verification
- Circuit/System Testing
- Repair Procedures
- DTC U1816
- Diagnostic Instructions
- DTC Descriptor
- Diagnostic Fault Information
- Circuit/System Description
- Conditions for Running the DTC
- Conditions for Setting the DTC
- Action Taken When the DTC Sets
- Conditions for Clearing the DTC
- Diagnostic Aids
- Reference Information
- Circuit/System Verification
- Circuit/System Testing
- Repair Procedures
- DTC U1817
- DTC U1818
- Diagnostic Instructions
- DTC Descriptor
- Diagnostic Fault Information
- Circuit/System Description
- Conditions for Running the DTC
- Conditions for Setting the DTC
- Action Taken When the DTC Sets
- Conditions for Clearing the DTC
- Diagnostic Aids
- Reference Information
- Circuit/System Verification
- Circuit/System Testing
- Repair Procedures
- DTC U1820
- DTC U1821
- DTC U182A
- Diagnostic Instructions
- DTC Descriptor
- Diagnostic Fault Information
- Circuit/System Description
- Conditions for Running the DTC
- Conditions for Setting the DTC
- Action Taken When the DTC Sets
- Conditions for Clearing the DTC
- Diagnostic Aids
- Reference Information
- Circuit/System Verification
- Circuit/System Testing
- Repair Procedures
- DTC U1842
- DTC U1843
- DTC U1862
- Diagnostic Instructions
- DTC Descriptor
- Diagnostic Fault Information
- Circuit/System Description
- Conditions for Running the DTC
- Conditions for Setting the DTC
- Action Taken When the DTC Sets
- Conditions for Clearing the DTC
- Diagnostic Aids
- Reference Information
- Circuit/System Verification
- Circuit/System Testing
- Repair Procedures
- DTC U1866
- DTC U186A
- DTC U186B
- DTC U1875
- DTC U1876
- DTC U1878
- DTC U1879
- DTC U1885
- DTC U1886
- DTC U1888
- DTC U189A
- Diagnostic Instructions
- DTC Descriptor
- Diagnostic Fault Information
- Circuit/System Description
- Conditions for Running the DTC
- Conditions for Setting the DTC
- Action Taken When the DTC Sets
- Conditions for Clearing the DTC
- Diagnostic Aids
- Reference Information
- Circuit/System Verification
- Circuit/System Testing
- Repair Procedures
- DTC U2099
- DTC U209A
- Diagnostic Instructions
- DTC Descriptor
- Diagnostic Fault Information
- Circuit/System Description
- Conditions for Running the DTC
- Conditions for Setting the DTC
- Action Taken When the DTC Sets
- Conditions for Clearing the DTC
- Diagnostic Aids
- Reference Information
- Circuit/System Verification
- Circuit/System Testing
- Repair Procedures
- DTC U209D
- DTC U2100
- DTC U2103
- DTC U2105-U2199
- Symptoms - Data Communications
- Scan Tool Does Not Power Up
- Scan Tool Does Not Communicate with High Speed GMLAN Device
- Scan Tool Does Not Communicate with Low Speed GMLAN Device
- Data Link References
- Repair Instructions
- Description and Operation
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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