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Tahoe / Yukon Service Manual

DTC B13AB

Cellular, Entertainment, and Navigation | Diagnostic Information and Procedures | Document ID: 5589727 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 Descriptors DTC B13AB WiFi Antenna Coaxial 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
Antenna Coax Cable WiFi B13AB 11 B13AB 13 — —

Circuit/System Description The infotainment system has two WiFi antennas, one internal to the radio and one external, connected to the A11 Radio via coax cable. This diagnostic refers to the external T4TA Auxiliary Wireless Communication Interface Antenna. The internal antenna is for in-vehicle WiFi connections. The external antenna is for outside of the vehicle WiFi connections and mainly used for OTA (Over The Air) updates and as a backup to the internal antenna if too many devices are connected to the internal antenna at the same time. The A11 Radio supplies 5V through the coax cable to power the internal antenna amplifier. Conditions for Running the DTC Ignition ON, A11 Radio On. System voltage is between 9-16 V. Conditions for Setting the DTC B13AB 11 The A11 Radio detects a short to ground on the WiFi antenna signal circuit. B13AB 13 The A11 Radio detects an open/high resistance on the WiFi antenna signal circuit. Action Taken When the DTC Sets Unable to access the WiFi hotspot. Conditions for Clearing the DTC The condition responsible for setting the DTC no longer exists. A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred. Diagnostic Aids g The T4TA Auxiliary Wireless Communication Interface Antenna requires a clear line of sight to the sky to operate properly. The T4TA Auxiliary Wireless Communication Interface Antenna may have limited, intermittent, or no reception near tall buildings or inside structures. 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 Testing

  1. Ignition OFF, disconnect the coax cable connector at the T4TA Auxiliary Wireless Communication Interface Antenna and at the A11 Radio.
  2. Verify the coax cable passes the coax cable component test. Refer to Component Testing. ⇒ If the coax cable does not pass the test Replace the coax cable ⇓ If the coax cable passes the test
  3. Test or replace the T4TA Auxiliary Wireless Communication Interface Antenna.
  4. Verify DTC B13AB is not set. ⇒ If DTC B13AB is set Replace the A11 Radio. ⇓ If DTC B13AB is not set
  5. All OK. Component Testing
  1. Ignition OFF, disconnect the coax cable at both components.
  2. Locate the appropriate pinout adaptor and load test loop adaptor from EL-52552 COAX FAKRA Cable Adaptor Kit.
  3. Connect the 2 adaptors together, measure and record the resistance between the terminals at
  4. Disconnect the 2 adaptors and connect each one to the appropriate end of the coax cable.
  5. At the pinout adapter, measure the total resistance of the coax cable loop including the connected load test adaptor. ⇒ If not within 5 Ω of the reading from step 3. Replace the coax cable ⇓ If within 5 Ω of the reading from step 3.
  6. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. For control module replacement, programming, and setup refer to: Control Module References