54A-CODE No.B1707 DETECTION OF TURN SIGNAL LIGHT (OPEN CIRCUIT)

DTC B1707: Flasher open

caution

Whenever the ECU is replaced, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.

TECHNICAL DESCRIPTION (COMMENT)

When the turn-signal light bulb is blown, or connector(s) or wiring harness between the ETACS-ECU, the turn-signal light which does not illuminate and ground is defective, the ETACS-ECU sets DTC B1707.

TROUBLESHOOTING HINTS

The side turn-signal light may be defective. <Fender panel type>
The side turn-signal light assembly may be defective. <Door mirror type>
The headlight assembly may be defective.
The rear combination light assembly may be defective.
The ETACS-ECU 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. Confirm which turn-signal light is defective.

Which turn-signal light fails to illuminate correctly?

Front turn-signal light : Go to Step 2

Side turn-signal light : Go to Step 7

Rear turn-signal light : Go to Step 12

STEP 2. Check the bulb(s) of the front turn-signal lights.

Check the bulb(s) of the defective light.

Is the check result normal?

Go to Step 3

Replace the bulb(s) of the defective light. Go to Step 17

STEP 3. Resistance measurement at the front combination light (turn: LH) connector or front combination light (turn: RH) connector.

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

(2) Resistance measurement between the defective light connector terminal and ground.

Measure the resistance between the front combination light (turn: LH) connector (ground terminal) and the ground.
Measure the resistance between the front combination light (turn: RH) connector (ground terminal) and the ground.

OK: The resistance should be 2 ohm or less.

Is the check result normal?

Go to Step 5

Go to Step 4

STEP 4. Check of open circuit in ground line between front combination light (turn: LH) connector or front combination light (turn: RH) connector and ground.

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

). Go to Step 17

Repair the connector(s) or wiring harness. Go to Step 17

STEP 5. Check of open circuit in TURN LH or TURN RH line between front combination light (turn: LH) connector or front combination light (turn: RH) connector and ETACS-ECU connector.

Is the check result normal?

Go to Step 6

Repair the connector(s) or wiring harness. Go to Step 17

STEP 6. Retest the system.

Check that the front turn-signal lights 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

). Go to Step 17

Replace the headlight assembly. Go to Step 17

STEP 7. Check the bulb(s) of side turn-signal lights.

Check the bulb(s) of the defective light.

Is the check result normal?

Go to Step 8

Replace the bulb(s) of the defective light. Go to Step 17

STEP 8. Resistance measurement at the side turn-signal light (LH) connector, side turn-signal light (RH) connector <Fender panel type>, door mirror assembly (LH) connector or door mirror assembly (RH) connector <Door mirror type>.

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

(2) Resistance measurement between the defective light connector terminal and ground.

Measure the resistance between the side turn-signal light (LH) connector (ground terminal) and the ground <Fender panel type>.
Measure the resistance between the side turn-signal light (RH) connector (ground terminal) and the ground <Fender panel type>.
Measure the resistance between the door mirror assembly (LH) connector (ground terminal) and the ground <Door mirror type>.
Measure the resistance between the door mirror assembly (RH) connector (ground terminal) and the ground <Door mirror type>.

OK: The resistance should be 2 ohm or less.

Is the check result normal?

Go to Step 10

Go to Step 9

STEP 9. Check of open circuit in ground line between side turn-signal light (LH) connector, side turn-signal light (RH) connector <Fender panel type>, door mirror assembly (LH) connector or door mirror assembly (RH) connector <Door mirror type> and ground.

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

Repair the connector(s) or wiring harness. Go to Step 17

STEP 10. Check of open circuit in TURN LH or TURN RH line between side turn-signal light (LH) connector, side turn-signal light (RH) connector <Fender panel type>, door mirror assembly (LH) connector or door mirror assembly (RH) connector <Door mirror type> and ETACS-ECU connector.

Is the check result normal?

Go to Step 11

Repair the connector(s) or wiring harness. Go to Step 17

STEP 11. Retest the system.

Check that the side turn-signal lights 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

). Go to Step 17

Replace the side turn-signal light <Fender panel type>, side turn-signal light assembly (Refer to GROUP 51 - Door Mirror

) <Door mirror type>. Go to Step 17

STEP 12. Check the bulb(s) of rear turn-signal lights.

Check the bulb(s) of the defective light.

Is the check result normal?

Go to Step 13

Replace the bulb(s) of the defective light. Go to Step 17

STEP 13. Resistance measurement at the rear combination light (turn: LH) or rear combination light (turn: RH) connector.

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

(2) Resistance measurement between the defective light connector terminal and ground.

Measure the resistance between the side rear combination light (turn: LH) connector (ground terminal) and the ground.
Measure the resistance between the side rear combination light (turn: RH) connector (ground terminal) and the ground.

OK: The resistance should be 2 ohm or less.

Is the check result normal?

Go to Step 15

Go to Step 14

STEP 14. Check of open circuit in ground line between rear combination light (turn: LH) connector or rear combination light (turn: RH) connector and ground.

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

). Go to Step 17

Repair the connector(s) or wiring harness. Go to Step 17

STEP 15. Check of open circuit in TURN LH or TURN RH line between rear combination light (turn: LH) connector or rear combination light (turn: RH) connector and ETACS-ECU connector.

Is the check result normal?

Go to Step 16

Repair the connector(s) or wiring harness. Go to Step 17

STEP 16. Retest the system.

Check that the rear turn-signal lights 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

). Go to Step 17

Replace the rear combination light. Go to Step 17

STEP 17. Using scan tool (M.U.T.-III), Check whether the diagnostic trouble code is set again.

(1)

caution

To prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).

Connect scan tool (M.U.T.-III). Refer to "How to connect Scan Tool (M.U.T.-III)

(2) Turn the ignition switch to the "ON" position.

(3) Erase the DTC.

(4) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.

(5) Check whether the ETACS-ECU DTC is set.

Is the DTC set?

Replace the ETACS-ECU.

The procedure is complete.