54A-ONE OF THE TAIL LIGHT OR THE LICENSE PLATE LIGHT DOES NOT ILLUMINATE.

Inspection Procedure 7: One of the position lights, the license plate lights or the taillights does not illuminate. <Up to 20 Model year>

TECHNICAL DESCRIPTION (COMMENT)

If one of the position lights, the license plate lights or taillights does not illuminate normally, the harness, connector(s), or bulb(s) may have a problem, or LED may have a problem, or the fuse may be burned out.

TROUBLESHOOTING HINTS

The bulbs or LED may be defective
The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector

DIAGNOSIS

Required Special Tools:

MB992006: Extra fine probe
MB991223: Harness set

STEP 1. Bulb check.

Check the bulb(s) or LED of the light that does not illuminate.

note	If LED-type position lights or LED-type taillights do not illuminate, their LED cannot be inspected. In this case, assume the LED to be normal and proceed with steps.

Is the check result normal?

Go to Step 2

: Replace the bulb(s) of the light that does not illuminate.

STEP 2. Resistance measurement at the headlight assembly (position/side maker: LH) or (position/side maker: RH) connector, rear combination light (tail/side maker: LH) or (tail/side maker: RH) connector, taillight (LH) or (RH) connector, license plate light (LH) or (RH) connector (ground terminal).

(1) Disconnect the connector, and measure at the wiring harness side.

(2) Measure the resistance between the connector terminal of light which does not illuminate and the body ground.

Measure the resistance between the headlight assembly (position/side maker: LH) or (position/side maker: RH) connector (ground terminals) and body ground.
Measure the resistance between the rear combination light (tail/side maker: LH) or (tail/side maker: RH) connector (ground terminals) and body ground.
Measure the resistance between the taillight (LH) or (RH) connector (ground terminals) and body ground.
Measure the resistance between the license plate light (LH) or (RH) connector (ground terminals) and body ground.

OK: The resistance should be 2 ohms or less

Is the check result normal?

Go to Step 4

Go to Step 3

STEP 3. Check of open circuit in ground lines between the headlight assembly (position/side maker: LH) or (position/side maker: RH) connector, rear combination light (tail/side maker: LH) or (tail/side maker: RH) connector, taillight (LH) or (RH) connector, license plate light (LH) or (RH) connector and body ground.

Is the check result normal?

Go to Step 5

Repair the connector(s) or wiring harness.

STEP 4. Check of open circuit in (TAL1, TAR1, TAL2, TAR2) lines between the headlight assembly (position/side maker: LH) or (position/side maker: RH) connector, rear combination light (tail/side maker: LH) or (tail/side maker: RH) connector, taillight (LH) or (RH) connector, license plate light (LH) or (RH) connector and ETACS-ECU connector.

Is the check result normal?

Go to Step 5

Repair the connector(s) or wiring harness.

STEP 5. Retest the system.

Check that the position light, taillight and license plate light illuminate normally.

Is the check result normal?

: The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction

: Replace the headlight assembly (position light).

: Replace the rear combination light.

: Replace the taillight assembly.

: Replace the license plate light socket.