Schematic Reference: Exterior Lights Schematics

1

Was the Lighting System Diagnostic System Check performed?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

Press the brake pedal.

Do the stop lamps operate properly?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

Are the turn signal lamps inoperative?

Go to Turn Signal Lamps and/or Indicators Inoperative

Go to Step 4

Are all of the stop lamps inoperative?

Go to Step 8

Go to Step 5

Are only the high mounted stop lamps inoperative?

Go to Step 6

Go to Step 10

1. Disconnect the inoperative center high mounted stop lamp (CHMSL).
2. With the brake pedal pressed, connect a test lamp between the stop lamp supply voltage circuit of the high mounted stop lamp and a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 17

Connect a test lamp between the stop lamp supply voltage circuit of the center high mounted stop lamp (CHMSL) and the ground circuit of the center high mounted stop lamp (CHMSL).

Does the test lamp illuminate?

Go to Step 13

Go to Step 16

1. Disconnect the stop lamp switch.
2. Connect a test lamp between the battery positive voltage circuit of the stop lamp switch and a good ground.

Does the test lamp illuminate?

Go to Step 9

Go to Step 12

1. Connect a 20 amp fused jumper between the battery positive voltage circuit of the stop lamp switch and the stop lamp supply voltage circuit of the stop lamp switch.
2. Observe the stop lamps.

Do the stop lamps illuminate?

Go to Step 14

Go to Step 17

1. Disconnect the turn/hazard switch.
2. Connect a test lamp between the stop lamp supply voltage circuit of the turn/hazard switch and a good ground.
3. Press brake pedal.

Does the test lamp illuminate?

Go to Step 11

Go to Step 17

1. Release brake pedal.
2. Connect a 20 amp fused jumper between the stop lamp supply voltage circuit of the turn/hazard switch and the appropriate stop/turn lamp supply voltage circuit.
3. Press the brake pedal.

Do the stop lamps illuminate?

Go to Step 15

Go to Step 13

Test an open or short to ground in the battery positive voltage circuit of the stop lamp switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 17

Inspect for poor connections at the inoperative stop lamp. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 18

Inspect for poor connections at the stop lamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 19

Inspect for poor connections at the turn/hazard switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 20

Repair an open or high resistance in the ground circuit of the stop lamps. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 21

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Repair an open or short to ground in the stop lamp supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 21

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Replace the inoperative stop lamp. Refer to High Mount Stop Lamp Replacement and Tail Lamp Bulb Replacement .

Did you complete the replacement?

Go to Step 21

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Replace the stop lamp switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes.

Did you complete the replacement?

Go to Step 21

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Replace the turn/hazard switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column.

Did you complete the replacement?

Go to Step 21

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2