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Tahoe / Yukon Service Manual

DTC B15AF

Cellular, Entertainment, and Navigation | Diagnostic Information and Procedures | Document ID: 5629636 Diagnostic Instructions Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Review Strategy Based Diagnosis for an overview of the diagnostic approach. Diagnostic Procedure Instructions provides an overview of each diagnostic category. DTC Descriptor DTC B15AF Human Machine Interface Low Voltage Differential Signaling LVDS Signal For symptom byte information refer to: Symptom Byte List Diagnostic Fault Information

Circuit Circuit Function Short to Ground Open/High Resistance Short to Voltage Signal Performan
7440 B+ B15AF:13 B15AF:11 — —
LVDS Cable Digital Video B15AF 02, 11 B15AF 04, 13 — —
1751 Ground — — — —

Circuit/System Description The infotainment display and controls are a separate component from the A11 Radio, combined into an assembly called the A22 Radio Control. The assembly is supplied battery voltage and ground from the vehicle harness. The A11 Radio communicates digital video data for on-screen display through a dedicated cable containing the LVDS data circuits. The Human Machine Interface is internal to the A11 Radio. If the A11 Radio detects the A22 Radio Control is not responding to the output on the LVDS circuits, the radio sets the DTC. Conditions for Running the DTC Ignition ON The system voltage is 9-16 V The infotainment system is ON The test is continuously when the infotainment system is operating Conditions for Setting the DTC B15AF 02 The A11 Radio detects a short to ground diagnostic status on the LVDS circuits. B15AF 04 The A11 Radio detects an open diagnostic status on the LVDS circuits. B15AF 11 The A11 Radio detects a short to ground on the LVDS circuits. B15AF 13 The A11 Radio detects an open on the LVDS circuits. Action Taken When the DTC Sets The A11 Radio sets this DTC No images are shown on the A22 Radio Control. Conditions for Clearing the DTC The A11 Radio detects a properly synced digital video signal. A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred. Reference Information Schematic Reference Radio/Navigation System Schematics Connector End View Reference Master Electrical Component List Description and Operation Radio/Audio System Description and Operation Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs Scan Tool Reference Control Module References for scan tool information Circuit/System Verification

  1. Verify no DTCs are present. ⇒ If any DTCs are present Refer to Diagnostic Trouble Code (DTC) List - Vehicle. ⇓ If no DTCs are present
  2. Ignition ON/vehicle in service mode, infotainment system ON, verify the Info Display shows an image. ⇒ If the Info Display does not show an image. Refer to Circuit/System Testing. ⇓ If the Info Display does show an image.
  3. All OK Circuit/System Testing
  4. Ignition OFF, disconnect the X1 connector at the A22 Radop Control.
  5. Test ground circuit terminal 8 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found.
  6. Verify that a test lamp illuminates between the B+ circuit terminal 1 and ground. ⇒ If the test lamp does not illuminate 3.1. Ignition OFF, remove the test lamp. 3.2. Test circuit 7440 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If the test lamp illuminates
  7. Verify the LVDS interface cable is properly connected at the A22 Radio Control and the A11 Radio and there is no damage to the cable or connections.
  8. Ignition ON/vehicle in service mode, infotainment system ON.
  9. Verify the A22 Radio Control displays an image. ⇒ If the A22 Radio Control does not display an image. Replace LVDS interface cable from the A22 Radio Control to the A11 Radio. 6.1. Ignition ON/vehicle in service mode, infotainment system ON. 6.2. Verify the A22 Radio Control displays an image. ⇒ If the A22 Radio Control does not display an image. Replace the A22 Radio Control. 6.3. Ignition ON/vehicle in service mode, infotainment system ON. 6.4. Verify the A22 Radio Control displays an image. ⇒ If the A22 Radio Control does not display an image. Replace the A11 Radio. ⇓ If the A22 Radio Control displays an image A fault is currently not present and may be an intermittent condition. ⇓ If the A22 Radio Control displays an image.
  10. A fault is currently not present and may be an intermittent condition. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. For control module replacement, programming, and setup refer to: Control Module References