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Tahoe / Yukon Service Manual

Dome Lamps Malfunction

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. Diagnostic Fault Information

Circuit Circuit Function Short to Ground Open/High Resistance Short to Voltage Signal Performan
240 B+ 1 1 — —
2904 Signal 1 1 — —
2905 Signal 1 1 — —
2908 Signal 1 1 — —
2910 Signal 1 1 — —
2903 Control 1 1 1 —
2906 Control 1 1 1 —
2907 Control 1 1 1 —
2909 Control 1 1 1 —
1850 Ground — 1 — —
1. Dome Lamps Malfunction

Circuit/System Description The dome/reading lamps are commanded ON when the DOOR switch on the overhead console assembly is on and any door or the rear hatch is opened. The jam switch contacts within the door/rear hatch close and the BCM receives a door/rear hatch-ajar input. The BCM will respond by sending a serial data message to the overhead console assembly to request the dome/reading lamps on. The overhead console responds by applying PWM voltage to all dome/reading lamp control circuits. In the event that a dome/reading lamp were to remain illuminated for more than 10 minutes with the ignition switch in the OFF position, the overhead console will deactivate the dome/reading lamp control circuit to prevent total battery discharge. Reference Information Schematic Reference Interior Lights Schematics Connector End View Reference Master Electrical Component List Description and Operation Interior Lighting 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. Ignition on/vehicle in service mode.
  2. Verify no communication DTCs are set. ⇒ If communication DTCs are set Refer to: Diagnostic Trouble Code (DTC) List - Vehicle ⇓ If communication DTCs are not set
  1. Verify the scan tool Door Ajar Switch parameter changes between Active and Inactive while opening and closing each vehicle door. ⇒ If the parameter does not change Refer to Door Ajar Indicator Malfunction. ⇓ If the parameter changes
  2. Verify DOOR is active on the overhead console assembly by pressing the DOOR button on the overhead console until the LED indicator is not illuminated.
  1. Open one of the doors and verify all of the dome/reading lamps turn on. ⇒ If one or more dome/reading lamp(s) do not turn on Refer to Dome/Reading Lamps Malfunction – Front if the front dome/reading lamp(s) do not turn on Refer to Dome/Reading Lamps Malfunction – Middle/Rear if the middle/rear dome/reading lamp(s) do not turn on ⇓ If all of the dome/reading lamps turn on
  1. Verify all of the dome/reading lamps turn off with all of the doors and rear hatch closed. ⇒ If one or more dome/reading lamp(s) do not turn off Refer to Dome/Reading Lamps Malfunction – Front if the front dome/reading lamp(s) do not turn off Refer to Dome/Reading Lamps Malfunction – Middle/Rear if the middle/rear dome/reading lamp(s) do not turn off ⇓ If all of the dome/reading lamps turn off
  2. Verify the dome/reading lamps turn on when pressing and releasing the dome/reading lamp lens, and turn off when pressing and releasing the dome/reading lamp lens a second time. ⇒ If one or more dome/reading lamp(s) do not turn on and off Refer to Dome/Reading Lamps Malfunction – Front if the front dome/reading lamp(s) do not turn on and off Refer to Dome/Reading Lamps Switch Malfunction – Middle/Rear if the middle/rear dome/reading lamp(s) do not turn on and off ⇓ If all of the dome/reading lamps turn on and off
  3. A fault is not currently present and may be an intermittent condition. Circuit/System Testing Dome/Reading Lamps Malfunction – Front
  4. Ignition/vehicle off, disconnect the connector at the A103 Roof Console.
  5. Verify a test lamp illuminates between ground circuit terminal 20 and B+. ⇒ If the test lamp does not illuminate 2.1. Repair the open/high resistance on ground circuit 1850 or ground connection. ⇓ If the test lamp illuminates
  6. Ignition on/vehicle in service mode, verify a test lamp illuminates between B+ circuit terminal 1 and ground. ⇒ If the test lamp does not illuminate and the circuit fuse is OK. 3.1. Test circuit 240 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. 3.2. Verify there is voltage at the fuse. ⇒ If the test lamp does not illuminate and the circuit fuse is open. 3.1. Test circuit 240 for a short to ground. ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found. 3.2. Replace the A103 Overhead Console Assembly. ⇓ If the test lamp illuminates
  7. Replace the A103 Overhead Console Assembly. Dome/Reading Lamps Malfunction – Middle/Rear
  1. Ignition/vehicle off, disconnect the connector at the A103 Roof Console.
  2. Connect a 3 A fused jumper wire between the appropriate control circuit terminal at the A103 Roof Console and B+: {C3U} E37H Roof Rail Rear Seat Position Reading and Courtesy Lamp – Left = Terminal  4 {C3U} E37J Roof Rail Rear Seat Position Reading and Courtesy Lamp – Right = Terminal  7 {Without C3U} E37SMA Rear Seat Position Center Reading and Courtesy Lamp – 2nd Row = Terminal 4 {Without C3U} E37SMA Rear Seat Position Center Reading and Courtesy Lamp – 2nd Row = Terminal 7 E37SMB Rear Seat Position Center Reading and Courtesy Lamp – 3rd Row = Terminal 11 E37SMB Rear Seat Position Center Reading and Courtesy Lamp – 3rd Row = Terminal 12  3. Verify the dome/reading lamp turns on and off when connecting and disconnecting the jumper wire ⇒ If the dome/reading lamp is always off and the fused jumper is OK. 3.1. Test for an open/high resistance on ground circuit 1850 at the dome/reading lamp. ⇒ If an open/high resistance is found, repair the fault on the circuit or ground connection. ⇓ If an open/high resistance is not found. 3.2. Test the appropriate control circuit for an open/high resistance: {C3U} E37H Roof Rail Rear Seat Position Reading and Courtesy Lamp – Left = Circuit 2903 {C3U} E37J Roof Rail Rear Seat Position Reading and Courtesy Lamp – Right = Circuit 2906 {Without C3U} E37SMA Rear Seat Position Center Reading and Courtesy Lamp – 2nd Row = Circuit 2903 {Without C3U} E37SMA Rear Seat Position Center Reading and Courtesy Lamp – 2nd Row = Circuit 2906 E37SMB Rear Seat Position Center Reading and Courtesy Lamp – 3rd Row = Circuit  2907 E37SMB Rear Seat Position Center Reading and Courtesy Lamp – 3rd Row = Circuit  2909 ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found. 3.3. Replace the E37 Dome/Reading Lamp. ⇒ If the dome/reading lamp is always off and the fused jumper is open. 3.1. Test the appropriate control circuit for a short to ground: {C3U} E37H Roof Rail Rear Seat Position Reading and Courtesy Lamp – Left = Circuit 2903 {C3U} E37J Roof Rail Rear Seat Position Reading and Courtesy Lamp – Right = Circuit 2906 {Without C3U} E37SMA Rear Seat Position Center Reading and Courtesy Lamp – 2nd Row = Circuit 2903 {Without C3U} E37SMA Rear Seat Position Center Reading and Courtesy Lamp – 2nd Row = Circuit 2906 E37SMB Rear Seat Position Center Reading and Courtesy Lamp – 3rd Row = Circuit  2907 E37SMB Rear Seat Position Center Reading and Courtesy Lamp – 3rd Row = Circuit  2909 ⇒ If an short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found. 3.2. Replace the E37 Dome/Reading Lamp. ⇒ If the dome/reading lamp is always on. 3.1. Test the appropriate control circuit for a short to voltage: {C3U} E37H Roof Rail Rear Seat Position Reading and Courtesy Lamp – Left = Circuit 2903 {C3U} E37J Roof Rail Rear Seat Position Reading and Courtesy Lamp – Right = Circuit 2906 {Without C3U} E37SMA Rear Seat Position Center Reading and Courtesy Lamp – 2nd Row = Circuit 2903 {Without C3U} E37SMA Rear Seat Position Center Reading and Courtesy Lamp – 2nd Row = Circuit 2906 E37SMB Rear Seat Position Center Reading and Courtesy Lamp – 3rd Row = Circuit  2907 E37SMB Rear Seat Position Center Reading and Courtesy Lamp – 3rd Row = Circuit  2909 ⇒ If an short to voltage is found, repair the fault on the circuit. ⇓ If a short to voltage is not found. 3.2. Replace the E37 Dome/Reading Lamp. ⇓ If the dome/reading lamp turns on and off
  3. Replace the A103 Roof Console. Dome/Reading Lamps Switch Malfunction – Middle/Rear
  1. Ignition/vehicle off, disconnect the connector at the A103 Roof Console.
  2. Connect a DMM between the appropriate control circuit terminal and ground: {C3U} E37H Roof Rail Rear Seat Position Reading and Courtesy Lamp – Left = Terminal  6 {C3U} E37J Roof Rail Rear Seat Position Reading and Courtesy Lamp – Right = Terminal  5 {Without C3U} E37SMA Rear Seat Position Center Reading and Courtesy Lamp – 2nd Row = Terminal 6 {Without C3U} E37SMA Rear Seat Position Center Reading and Courtesy Lamp – 2nd Row = Terminal 5 E37SMB Rear Seat Position Center Reading and Courtesy Lamp – 3rd Row = Terminal 8 E37SMB Rear Seat Position Center Reading and Courtesy Lamp – 3rd Row = Terminal 9
  3. Test for infinite resistance with the dome/reading lamp at rest. ⇒ If less than infinite resistance 3.1. Test the appropriate signal circuit for a short to ground: {C3U} E37H Roof Rail Rear Seat Position Reading and Courtesy Lamp – Left = Circuit 2904 {C3U} E37J Roof Rail Rear Seat Position Reading and Courtesy Lamp – Right = Circuit 2905 {Without C3U} E37SMA Rear Seat Position Center Reading and Courtesy Lamp – 2nd Row = Circuit 2904 {Without C3U} E37SMA Rear Seat Position Center Reading and Courtesy Lamp – 2nd Row = Circuit 2905 E37SMB Rear Seat Position Center Reading and Courtesy Lamp – 3rd Row = Circuit  2908 E37SMB Rear Seat Position Center Reading and Courtesy Lamp – 3rd Row = Circuit  2910 ⇒ If an short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found. 3.2. Replace the E37 Dome/Reading Lamp. ⇓ If infinite resistance
  4. Test for less than infinite resistance when pressing and holding the dome/reading lamp lens. ⇒ If infinite resistance 4.1. Test for an open/high resistance on ground circuit 1850 at the dome/reading lamp. ⇒ If an open/high resistance is found, repair the fault on the circuit or ground connection. ⇓ If an open/high resistance is not found. 4.2. Test the appropriate signal circuit for an open/high resistance: {C3U} E37H Roof Rail Rear Seat Position Reading and Courtesy Lamp – Left = Circuit 2904 {C3U} E37J Roof Rail Rear Seat Position Reading and Courtesy Lamp – Right = Circuit 2905 {Without C3U} E37SMA Rear Seat Position Center Reading and Courtesy Lamp – 2nd Row = Circuit 2904 {Without C3U} E37SMA Rear Seat Position Center Reading and Courtesy Lamp – 2nd Row = Circuit 2905 E37SMB Rear Seat Position Center Reading and Courtesy Lamp – 3rd Row = Circuit  2908 E37SMB Rear Seat Position Center Reading and Courtesy Lamp – 3rd Row = Circuit  2910 ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found. 4.3. Replace the E37 Dome/Reading Lamp. ⇓ If less than infinite resistance
  5. Replace the A103 Roof Console. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Lighting Component Replacement Reference Control Module References for BCM replacement, programming, and setup