2009 Impreza 5-door left tail light and turn signal don't work .

Stop Lamps
The brake pedal position sensor is used to sense the action of the driver application of the brake pedal. The body control module (BCM) provides a 5-volt reference voltage and low reference to the brake pedal position sensor. The position sensor provides an analog voltage signal back to the BCM that will increase as the brake pedal is applied. When the brake is applied, the BCM will then apply battery voltage to the left and right stop/turn signal lamp supply voltage circuits and the center high mounted stop lamp (CHMSL) supply voltage circuit illuminating the stop lamps. At the same time the BCM applies battery voltage through the signal circuit to the transmission control module (TCM) and the engine control module (ECM) indicating that the brakes are applied.
Ground for the stop lamps is supplied as follows:
• G402 provides ground for the left rear stop/tail/turn signal lamps
• G403 provides ground for the right rear stop/tail/turn signal lamps
• G301 provides ground for the CHMSL
The stop lamps on this vehicle will not illuminate unless the ignition is in the accessory, run, or crank positions. When the ignition is in the OFF position the stop lamps will not illuminate when the brake pedal is applied.
Battery voltage from the LT TRN/SIG and RT TRN/SIG fuses located in the rear fuse block is also used by the body control module (BCM) for stop lamp operation.

Turn Signal Lamps
Battery voltage supplied to the body control module (BCM) from the fuses listed below is used for turn signal and hazard lamp operation.
• LT TRN/SIG fuse for the left turn signals
• CTSY/RF TRN fuse for the right front turn signal
• RR TRN/SIG fuse for the right rear turn signal
When the turn signal switch is place in either the LEFT or RIGHT position, ground from G300 is applied through the turn signal switch signal circuit to the BCM indicating the turn signal request. In response to this signal, the BCM applies a pulsating voltage to the front and rear turn signal lamps supply voltage circuits cycling the lamps ON and OFF. At the same time the BCM sends a GMLAN serial data message to the instrument panel cluster (IPC) to cycle the appropriate turn signal indicator ON and OFF.
Ground for the turn signal lamps is supplied as follows:
• G104 provides ground for the left and right front turn signal lamps
• G402 provides ground for the left rear stop/tail/turn signal lamps
• G403 provides ground for the right rear stop/tail/turn signal lamps

Do you have a factory scan tool (tech2) ? Your best bet , take it to the dealer .

Hi, you need to test if the power is coming to the plug for rear brake light. If the power is not there that is your first problems. Also may have earth wire problem.

The turn signals and brake lights use the same circuit and filament in the bulbs. The tail lights are on the other circuit which comes from the headlight switch.
Do you have power on the tail light fuse ?

need more ifo

Turn Signal Lamps
The LT T/SIG and RT T/SIG fuses located in the underhood fuse block supplies battery positive voltage to the body control module (BCM) for turn signal and hazard lamp operation. When the turn signal switch is place in either the LEFT or RIGHT position, ground from G202 is applied through the turn signal switch signal circuit to the BCM indicating the turn signal request. In response to this signal, the BCM applies a pulsating voltage to the front and rear turn signal lamps supply voltage circuits cycling the lamps ON and OFF. The BCM also sends a message via GMLAN to the instrument panel cluster (IPC) to cycle the turn signal indicator ON and OFF depending on the position of the turn signal switch.
Ground for the turn signal lamps is supplied as follows:
• G101 provides ground for the left front turn signal lamp
• G100 provides ground for the right front turn signal lamp
• G302 provides ground for the left and right rear turn signal lamps

The LT T/SIG and RT T/SIG fuses located in the underhood fuse block are also used by the body control module (BCM) for stop lamp operation.
The brake pedal position sensor is used to sense the action of the driver application of the brake pedal. The body control module (BCM) provides both, a 5-volt reference voltage and low reference to the brake pedal position sensor. The position sensor provides an analog voltage signal back to the BCM that will increase as the brake pedal is applied. When the brake pedal is applied, the BCM will then apply battery voltage to the left and right stop lamp supply voltage circuits and the center high mounted stop lamp (CHMSL) supply voltage circuit illuminating the stop lamps. At the same time the BCM signals the transmission control module (TCM) and the engine control module (ECM) that the brakes are applied. Ground for all stop lamps is provided at G302.
The stop lamps on this vehicle will not illuminate unless the ignition is in the accessory, run, or crank positions. When the ignition is in the OFF position the stop lamps will not illuminate when the brake pedal is applied.

Did you check the fuse's. ? Wouldn't think it's a ground because right an left tail lamp Assembly's use same ground ! Did you check for B+ voltage at the bulb. with a volt meter ? Power is supplied by the BCM . Could be the tail lamp assembly

in the rear lights you may have two bulbs one is the turn signal the other one is stop light / tail light the stop light / tail light has two filaments, one for the stop light (21 watt) & one for the tail light (5 watt) it is possible that the tail light filament is blown, try replacing the bulb to see if that fixes the problem,also check all the fuses as well.......hope this helps......cheers.

When you are talking about "indicators" we could assuming that your are refer about signal lights. This work with "flashers" devices.

For 1996 Audi A4 2.8L SFI 6cyl the Flasher is located in front seating area, driver side, under dash, behind dash lower panel, mounted above driver side of steering column.

About generic fuses, open the driver side door. Remove panel on left side of dash. Fuse box is behind panel:

Fuse # / Description / Amps
1 / Heated washer jets / 5
2 / Turn signals flasher unit / 10
3 / Headlight washer, illumination of glove compartment, engine compartment, climate control, automatic transmission, instrument cluster / 5
4 / License plate light / 5
5 / Instrument cluster, seat heating, test connection for cruise control, bulb monitor for auto-check control, Automatic transmission display, switch lighting, mirror switches and actuators, airbag warning light, outside temperature indicator, Climate control / 10
6 / Central locking system / 5
7 / Anti-lock brake system / 10
8 / Vacant
9 / Mirror heating / 10
10 / Vacant
11 / Cruise control (automatic transmission) / 5
12 / On board diagnostic system / 10
13 / Brake lights / 10
14 / Interior lights, reading lights, anti-theft alarm system, vanity mirror / 10
15 / Instrument cluster, power windows, climate control, automatic transmission / 10
16 / Anti-lock brake system, Anti-Slip-Regulation / 5
17 / Heated door locks / 10
18 / High beam right / 10
19 / High beam left / 10
20 / Low beam right / 15
21 / Low beam left / 15
22 / Tail and side marker right / 5
23 / Tail and side marker left / 5
24 / Wiper and washer system / 25
25 / Blower for heating, climate control / 30
26 / Rear window defogger, mirror heating / 30
27 / Rear window wiper / 15
28 / Fuel pump / 15
29 / Engine timing / 20
30 / Sun roof / 20
31 / Tail lights, cruise control, automatic transmission / 15
32 / Engine timing / 20
33 / Cigarette lighter / 15
34 / Engine timing / 15
35 / Trailer receptacle / 30
36 / Fog lights / 15
37 / Radio / 20
38 / Luggage compartment light, central locking system / 15
39 / Emergency flasher / 15
40 / Horn / 25
41 / Anti-lock brake system / 25
42 / Vacant
43 / Vacant
44 / Seat heating / 30

Hope this helps (remember to rate and comme this free answeer).

Cavity
1 20 amp yellow hazard flashers
2 10 amp red heated mirrors
3 20 amp yellow body lights
4 not used
5 20 amp yellow windshield wipers
6 20 amp yellow turn signal lights
7 10 amp red radio
8 not used
9 7.5 amp violet illumination lights
10 2 amp pink left tail lights
11 2 amp right tail lights
12 not used
13 20 amp yellow rear window wiper/washer
14 2 amp pink speed control
15 10 amp red gauges, warning lights
16 not used
17 10 amp red left low beam headlight
18 10 amp red right low beam headlight
19 20 amp yellow stop lights
20 20 amp yellow rear a/c heat
21 20 amp yellow fog lights
22 20 amp yellow park lights
23 20 amp yellow battery
24 20 amp yellow back up lights
25 circuit breaker power windows,power vent windows
26 30 amp lt. green a/c heater blower motor
27 circuit breaker power door locks
28 not used