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Tahoe / Yukon Service Manual

DTC B1383 or B19EB

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 B1383 Front Sunshade Switch Signal DTC B19EB Rear Sunshade Switch Signal For symptom byte information refer to Symptom Byte List. Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performanc
Signal B1383 11 B1383 15 B1383 15 B1383 23
Low Reference B1383 11 B1383 15 B1383 15 B1383 23
Signal B19EB 11 B19EB 15 B19EB 15 B19EB 23
Low Reference B19EB 11 B19EB 15 B19EB 15 B19EB 23

Circuit/System Description The sunroof switch is connected directly to the sunroof motor and provides detent positions for open, express open, off, close, and express close. The sunroof switch completes the circuit between two signals proved by the sunroof motor, a reference ground input and a pull-up voltage provided by an analog to digital switch input. The sunroof switch places a different resistor ladder network in the circuit depending on the function selected. Conditions for Running the DTC The ignition is ON. Conditions for Setting the DTC B1383 11 or B19EB 11 The sunroof motor has detected and reported via serial data that the sunroof switch signal is shorted to ground. B1383 15 or B19EB 15 The sunroof motor has detected and reported via serial data that the sunroof switch signal is open or shorted to voltage. B1383 23 or B19EB 23 The sunroof motor has detected and reported via serial data that the sunroof switch has been in the same active position for 20 s after the glass has stopped moving in the requested direction due to reaching the end of the allowable motion. Action Taken When the DTC Sets DTC is stored in the body control module (BCM) memory. Conditions for Clearing the DTC The BCM no longer detects a malfunction in the sunroof switch signal circuit. Reference Information Schematic Reference Sunroof Schematics Connector End View Reference Master Electrical Component List Description and Operation Sunroof 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 and all vehicle systems OFF, disconnect the harness connector at the A103 Roof Console. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 10 Ω between the low reference circuit terminal and ground. ⇒ If 10 Ω or greater 2.1. Ignition OFF, disconnect the harness connector at the M81F Sunroof Sunshade Motor - Front. 2.2. Test for less than 2 Ω in the low reference circuit end to end. ⇒ If 2 Ω or greater, repair the open/high resistance in the circuit. ⇒ If less than 2 Ω , test or replace the M81F Sunroof Sunshade Motor - Front. ⇓ If less than 10 Ω
  3. Ignition ON.
  4. Test for 4.8–5.2 V between the 5 V reference circuit terminal and ground. ⇒ If less than 4.8 V 4.1. Ignition OFF, disconnect the harness connector at the M81F Sunroof Sunshade Motor - Front. 4.2. Test for infinite resistance between the 5 V reference circuit and ground. ⇒ If less than infinite resistance, repair the short to ground on the circuit. ⇓ If infinite resistance 4.3. Test for less than 2 Ω in the 5 V reference circuit end to end. ⇒ If 2 Ω or greater, repair the open/high resistance in the circuit. ⇒ If less than 2 Ω, replace the M81F Sunroof Sunshade Motor - Front. ⇒ If greater than 5.2 V 4.1. Ignition OFF, disconnect the harness connector at the M81F Sunroof Sunshade Motor - Front, ignition ON. 4.2. Test for less than 1 V between the 5 V reference circuit and ground. ⇒ If 1 V or greater, repair the short to voltage on the circuit. ⇒ If less than 1 V, replace the M81F Sunroof Sunshade Motor - Front. ⇓ If between 4.8–5.2 V
  5. Test or replace the A103 Roof Console. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Control Module References for sunshade motor/actuator replacement, setup and programming