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Tahoe / Yukon Service Manual

DTC B19F6

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 Content Theft Deterrent Sensor For symptom byte information, refer to Symptom Byte List. Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performanc
B+ — B19F6, 49, 54, 55 — —
Serial Data B19F6, 49, 54, 55 B19F6, 49, 54, 55 B19F6, 49, 54, 55 B19F6, 49, 54, 55
Ground — B19F6, 49, 54, 55 — —

Circuit/System Description The body control module performs various communication fault detection tests to determine if a software, hardware, or communication concern exists with the ultrasonic intrusion sensor. The sensor being disconnected, a poor connection at the connector, or the vehicle battery being discharged could all cause the communication to be interrupted. This interruption stops the self test from completing which causes DTC B19F3. This is not because of the sensor failing, it is because of a previous or existing open connection between the sensor and the BCM. Restoring this connection and then arming the theft system will complete the test and allow the DTC to be cleared. Conditions for Running the DTC The ignition is OFF. The vehicle is in Park. Conditions for Setting the DTC The body control module cannot establish communications with the ultrasonic intrusion sensor. Action Taken When the DTC Sets The intrusion and inclination alarm output is disabled. Conditions for Clearing the DTC A current DTC is cleared when the conditions for setting the DTC are no longer present and the system has been armed. A history DTC will clear after 40 malfunction-free ignition cycles. Diagnostic Aids Before performing any diagnostic procedures, ensure the sensor is properly connected and arm the theft system. After the system has been armed long enough to have performed the tests within the system, disarm the theft system and attempt to clear the DTC. Reference Information Schematic Reference Theft Deterrent System Schematics Connector End View Reference Master Electrical Component List Description and Operation Theft Systems 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. Vehicle OFF, close and lock the doors using the keyless entry transmitter.
  2. Arm the theft system and wait 5 min.
  3. Disarm the system.
  4. Attempt to clear the DTC. ⇒ If the DTC will not clear or transition to a history DTC Perform Circuit/System Testing. ⇓ If the DTC clears or transitions to a history DTC
  5. All OK. Circuit/System Testing
  6. Ignition OFF and vehicle systems OFF, disconnect the harness connector at the B165 Content Theft Deterrent Sensor Module. It may take up to 2 min for all vehicle systems to power down.
  7. Test for less than 10 Ω between the ground circuit terminal 5 and ground. ⇒ If 10 Ω or greater 2.1. Ignition OFF. 2.2. Test for less than 2 Ω in the ground circuit end to end. ⇒ If 2 Ω or greater, repair the open/high resistance in the circuit. ⇒ If less than 2 Ω, repair the open/high resistance in the ground connection. ⇓ If less than 10 Ω
  8. Ignition ON.
  9. Verify a test lamp illuminates between the B+ circuit terminal 3 and ground. ⇒ If the test lamp does not illuminate and the circuit fuse is good 4.1. Ignition OFF. 4.2. Test for less than 2 Ω in the B+ circuit end to end. ⇒ If 2 Ω or greater, repair the open/high resistance in the circuit. ⇒ If less than 2 Ω, verify the fuse is OK and there is voltage at the fuse. ⇒ If the test lamp does not illuminate and the circuit fuse is open 4.1. Ignition OFF. 4.2. Test for infinite resistance between the B+ circuit and ground. ⇒ If less than infinite resistance, repair the short to ground on the circuit. ⇒ If infinite resistance, replace the B165 Content Theft Deterrent Sensor Module. ⇓ If the test lamp illuminates
  10. Ignition OFF, arm the content theft deterrent system.
  11. Test for greater than 4.5 V between the serial data circuit terminal 4 and ground. ⇒ If 4.5 V or less 6.1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module. 6.2. Test for infinite resistance between the serial data circuit and ground. ⇒ If less than infinite resistance, repair the short to ground on the circuit. ⇓ If infinite resistance 6.3. Test for less than 2 Ω in the serial data circuit end to end. ⇒ If 2 Ω or greater, repair the open/high resistance in the circuit. ⇒ If less than 2 Ω, replace the K9 Body Control Module. ⇓ If greater than 4.5 V
  12. Ignition OFF, disconnect the harness connector at the K9 Body Control Module and any other components or control modules sharing the serial data circuit with the B165 Content Theft Deterrent Sensor Module, ignition ON.
  13. Test for less than 1 V between the B165 Content Theft Deterrent Sensor Module serial data circuit terminal 4 and ground. ⇒ If 1 V or greater Repair the short to voltage on the circuit. ⇓ If less than 1 V
  14. Test or replace the B165 Content Theft Deterrent Sensor Module.
  15. Fully arm then disarm the content theft deterrent system and verify no DTCs are set. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Control Module References for replacement, programming, and setup. Content Theft Deterrent Sensor Replacement