Diagnostics and testing of interior lighting (Discovery 3)

Inspection and verification

1. Make sure the customer's complaint is valid.

2. Visually inspect for obvious electrical problems.

Mechanical factors

Electrical Factors

The main ceiling light interior - condition and correct installation Lamp condition and installation (lamps) for reading Lamp condition and installation (lamps) cosmetic mirror lighting Condition and installation of the glove compartment light Lamp condition and installation (lamps) footwell lighting Condition and installation of illumination of an edging frame of the ignition switch Condition and installation of additional marker lights Lamp condition and installation (lamps) highlights in ode Condition and installation of the luggage compartment light

Lamps Fuses Battery Electrical Junction Box (BJB) - fuse link 15E BJB - fusible link 11E Central electrical box (CJB) - fuse 1P BJB CJB Battery Save Relay Wiring harness Loose or corroded connector (ov) Interior light main switch Reading light switches Vanity mirror light switches Glove compartment lamp switch Flowing LED tailgate lamp switch

3. If an obvious cause of a problem you identified or described by a customer is found, resolve it before proceeding to the next steps (if possible).

4. Use an approved diagnostic system or scan tool (tester), to retrieve all DTCs before referring to the symptom table or DTC index (DTC).

Clear all DTCs after troubleshooting.

Symptom table

Symptom	Possible reasons	Actions
Main interior light does not work	Lamp defective (s) Fuse (And) burned out Electrical circuit malfunction Switch failure	Check Lamp Condition (lamps). Check fuse (And) (see visual inspection). Check lamp circuits. Check switch operation. Refer to the electrical manual.
Flashing LED not working	Faulty LED Fuse (And) burned out Electrical circuit malfunction	Check the status of the LED. Check the LED connector. Check fuse (And) (see visual inspection). Check lamp circuits. Refer to the electrical manual.
Lamp not working (s) for reading	Lamp defective (s) Fuse (And) burned out Electrical circuit malfunction Switch failure	Check Lamp Condition (lamps). Check fuse (And) (see visual inspection). Check lamp circuits. Check switch operation. Refer to the electrical manual.
Flashlight not working (And) cosmetic mirror lighting	Lamp failure Fuse (And) burned out Electrical circuit malfunction Switch failure	Check the condition of the lamp. Check fuse (And) (see visual inspection). Check lamp circuits. Check switch operation. Refer to the electrical manual.
Glove compartment light not working	Lamp failure Fuse (And) burned out Electrical circuit malfunction Switch failure	Check the condition of the lamp. Check fuse (And) (see visual inspection). Check lamp circuits. Check switch operation. Refer to the electrical manual.
Flashlight not working (And) footwell lighting	Lamp failure Fuse (And) burned out Electrical circuit malfunction	Check the condition of the lamp. Check fuse (And) (see visual inspection). Check lamp circuits. Refer to the electrical manual.
The illumination of the edging frame of the ignition switch does not work	Faulty lamp/edging frame Fuse (And) burned out Electrical circuit malfunction	Check the condition of the lamp/edging frame. Check fuse (And) (see visual inspection). Check lamp circuits. Refer to the electrical manual.
Overall does not work (s) flashlight (And), built into the exterior mirror	Lamp failure Fuse (And) burned out Electrical circuit malfunction	Check the condition of the lamp. Check fuse (And) (see visual inspection). Check lamp circuits. Refer to the electrical manual.
Flashlight not working (And) entrance illumination	Lamp failure Fuse (And) burned out Electrical circuit malfunction	Check the condition of the lamp. Check fuse (And) (see visual inspection). Check lamp circuits. Refer to the electrical manual.
Luggage compartment light not working	Lamp failure Fuse (And) burned out Electrical circuit malfunction Switch failure	Check the condition of the lamp. Check fuse (And) (see visual inspection). Check lamp circuits. Check switch operation. Refer to the electrical manual.

DTC index

NOTE: Universal Scan Tools cannot read the listed codes or can only read 5-digit codes. Match the 5 digits from the scan tool with the first 5 digits of the listed 7 digit code to identify the problem (the last 2 digits give additional information read by the diagnostic system approved by the manufacturer).

DTCs	Description	Possible reasons	Actions
B1C4323	Main interior light switch	Signal stuck Switch pressed Interior lamp circuit - short to ground The switch of a plafond of illumination of salon is faulty	Refer to the guided diagnostic program for this code on the approved diagnostic system. Check the interior lamp circuit according to the electrical manual. Check switch operation and replace if necessary.
B1C9511	Electrical circuit for auxiliary marker lights	Additional position lamps circuit - short circuit to ground	Refer to the guided diagnostic program for this code on the approved diagnostic system. Refer to the electrical manuals and check the auxiliary position lamp circuit (in the presence of). Replace/repair as needed. If there is no such device, check the vehicle configuration. Erase/ignore DTC.
B1C9515	Electrical circuit for auxiliary marker lights	Auxiliary marker lights circuit short to battery	Refer to the guided diagnostic program for this code on the approved diagnostic system. Refer to the electrical manuals and check the auxiliary position lamp circuit (in the presence of). Replace/repair as needed. If there is no such device, check the vehicle configuration. Erase/ignore DTC.
B1D1311	Interior lighting circuit "A"	Interior lighting circuit A short circuit to ground	Refer to the guided diagnostic program for this code on the approved diagnostic system. Refer to the electrical manuals and check the circuit. Repair if necessary.
B1D1315	Interior lighting circuit "A"	Interior lighting circuit A short circuit to battery	Refer to the guided diagnostic program for this code on the approved diagnostic system. If there is no customer complaint about interior lighting operation, no action is required, clear/ignore the DTC. If the interior lighting does not work properly, refer to the electrical manuals and check the circuit. Repair if necessary.
B1D1411	Interior lighting circuit "IN"	Interior lighting circuit B - short to ground	Refer to the guided diagnostic program for this code on the approved diagnostic system. Refer to the electrical manuals and check the circuit. Repair if necessary.
B1D1415	Interior lighting circuit "IN"	Footwell/entrance lights not fitted Lamp failure Fuse (And) burned out Electrical circuit malfunction	Check the installation of the footwell/entrance lights. If lights are NOT installed, ignore this DTC. If the lights are installed, refer to the guided diagnostic program for this code on the approved diagnostic system. Check the condition of the bulbs/fuses. Refer to the electrical diagrams and check the lamp circuits for short circuits, open circuits.