Pinpoint Test C: The Courtesy Lamp(s) Stay On Continuously
Interior Lighting
Pinpoint Tests
Pinpoint Test C: The Courtesy Lamp(s) Stay On Continuously
Refer to Wiring Diagram Set 89, Interior Lamps for schematic and connector information. Diagrams By Number
Refer to Wiring Diagram Set 59, Multifunction Control Modules for schematic and connector information. Diagrams By Number
Normal Operation
The Generic Electronic Module (GEM) supplies voltage to the interior lamps through the battery saver output circuit. To control the illumination of the courtesy lamps, the GEM grounds the control side of the courtesy lamp relay located in the Central Junction Box (CJB). When the relay is energized, ground is supplied to the interior lamps.
The GEM monitors the door ajar switch status. When the doors are closed, the door ajar switches are open, removing ground to the GEM. When the GEM determines a door is open, the GEM then energizes the courtesy lamp relay to illuminate the interior lamps.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Courtesy lamp relay
- Door ajar switch
- Front interior lamp
- GEM
PINPOINT TEST C: THE COURTESY LAMP(S) STAY ON CONTINUOUSLY
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Make sure all doors are closed and the dimmer switch is NOT in the ON position.
-------------------------------------------------
C1 CHECK THE DOOR AJAR PIDs
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: GEM DataLogger.
- Monitor the GEM door ajar PIDs (D_DR_SW, P_DR_SW, LRDR_SW, and RRDR_SW) while opening and closing all the doors.
- Do the door ajar PIDs agree with the door positions?
Yes
GO to C2.
No
GO to C6.
-------------------------------------------------
C2 ISOLATE THE SHORT TO GROUND
- Disconnect: Courtesy Lamp Relay.
- Do the interior lamps remain illuminated?
Yes
GO to C3.
No
GO to C4.
-------------------------------------------------
C3 CHECK THE INTERIOR LAMP CIRCUIT FOR A SHORT TO GROUND
- Disconnect: Front Interior Lamp C931b.
- Measure the resistance between the front interior lamp C931b-1, circuit 31S-LC7 (BK/BU), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
REPAIR circuit 31S-LC7 (BK/BU) for a short to ground. TEST the system for normal operation
No
INSTALL a new front interior lamp. REFER to Interior Lamp Service and Repair. TEST the system for normal operation.
-------------------------------------------------
C4 CHECK THE COURTESY LAMP RELAY
- Substitute a known good relay and observe the interior lamps.
- Do the interior lamps remain illuminated?
Yes
REMOVE the known good relay. GO to C5.
No
REMOVE the known good relay. INSTALL a new courtesy lamp relay. TEST the system for normal operation.
-------------------------------------------------
C5 CHECK THE COURTESY LAMP RELAY CONTROL CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Connect: Courtesy Lamp Relay.
- Disconnect: GEM C201e.
- Measure the voltage between the GEM C201e-21, circuit 31S-LC18 (BK/BU), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to C8.
No
REPAIR circuit 31S-LC18 (BK/BU) for a short to ground. TEST the system for normal operation.
-------------------------------------------------
C6 CHECK THE DOOR AJAR SWITCH OPERATION
NOTE: If the sliding doors ajar input is the cause of the concern, disconnect the sliding door ajar switches one at a time to isolate the suspect door ajar switch.
- Enter the following diagnostic mode on the scan tool: GEM DataLogger.
- Monitor the GEM door ajar PIDs (D_DR_SW, P_DR_SW, LRDR_SW, and RRDR_SW) while disconnecting the suspect door ajar switch/latch.
- Disconnect: Suspect Door Ajar Switch/Latch.
- Does the GEM door ajar PID read closed when the suspect door ajar switch/latch is disconnected?
Yes
INSTALL a new door ajar switch or latch in question. REFER to Handles, Locks, Latches and Entry Systems Service and Repair. TEST the system for normal operation.
No
GO to C7.
-------------------------------------------------
C7 CHECK THE DOOR AJAR SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Disconnect: GEM C201e.
- Measure the resistance between the GEM, harness side and ground for the inoperative door ajar switch input as follows:
- Is the resistance greater than 10,000 ohms?
Yes
GO to C8.
No
REPAIR the door ajar signal circuit in question for a short to ground for normal operation.
-------------------------------------------------
C8 CHECK FOR CORRECT GEM OPERATION
- Disconnect all the GEM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the GEM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new GEM. REFER to Multifunction Electronic Modules Service and Repair. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
-------------------------------------------------