B16A4

DTC B16A4: Blown turn-signal light (RH) bulb






















DIAGNOSTIC FUNCTION

When the right bulb of turn-signal light is blown, the ETACS-ECU sets DTC B16A4.

TECHNICAL DESCRIPTION (COMMENT)

The ETACS-ECU sets DTC B16A4 under the following conditions.

- If there is a malfunction to the right turn-signal light bulb, the blown right bulb counter counts once when the illumination of hazard or turn-signal light (right side) is attempted.
- If the blown right bulb counter reaches "3," the DTC B16A4 is set.

TROUBLESHOOTING HINTS

- Malfunction of turn-signal light bulb (right side)
- Malfunction of the ETACS-ECU
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector

DIAGNOSIS

Required Special Tools:

- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)

STEP 1. Bulb check.

Check whether the bulb of turn-signal light which does not illuminate is normal.

Q. Is the check result normal?

YES Go to Step 2.
NO Replace the bulb of turn-signal light which does not illuminate.
STEP 2. Check headlight assembly (RH) connector A-57 [front], side turn-signal light (RH) connector A-02 [side], rear combination light
(RH) connector F-06 [rear] for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Are headlight assembly (RH) connector A-57[ front], side turn-signal light (RH) connector A-02[ side], rear combination light (RH) connector F-06[ rear] in good condition?

YES Go to Step 3.
NO : Repair or replace the damaged component(s). Harness Connector Inspection.
STEP 3. Resistance measurement at headlight assembly (RH) connector A-57 [front], side turn-signal light (RH) connector A-02 [side], and rear combination light (RH) connector F-06 [rear].

(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 body ground.

- Measure the resistance between the headlight assembly (RH) connector A-57 (terminal 6) and body ground.[ Front]
- Measure the resistance between the side turn-signal light (RH) connector A-02 (terminal 1) and body ground.[ side]
- Measure the resistance between the rear combination light (RH) connector F-06 (terminal 1) and body ground.[ Rear]
OK: The measured value should be continuity exists (2 ohm or less).

Q. Does the measured resistance value correspond with this range?

YES Go to Step 5.

NO Go to Step 4.

STEP 4. Check the wiring harness between headlight assembly (RH) connector A-57 (terminal 6) [front], side turn-signal light (RH) connector A-02 (terminal 1) [side], rear combination light (RH) connector F-06 (terminal 1) [rear] and ground.

- Check the ground wires for open circuit.

Q. Are the wiring harness between headlight assembly (RH) connector A-57 (terminal 6)[ front], side turn-signal light (RH) connector A-02 (terminal 1)[ side], rear combination light (RH) connector F-06 (terminal 1)[ rear] and ground in good condition?

YES Go to Step 7.
NO The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.
STEP 5. Check ETACS-ECU connectors C-304 and C-311 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Are ETACS-ECU connectors C-304 and C-311 in good condition?

YES Go to Step 6.
NO Repair or replace the damaged component(s). Harness Connector Inspection.
STEP 6. Check the wiring harness between headlight assembly (RH) connector A-57 (terminal 3) [front], side turn-signal light (RH) connector A-02 (terminal 2) [side], rear combination light (RH) connector F-06 (terminal 2) [rear] and ETACS-ECU connector C-304 (terminal 16) [front or side] or C-311 (terminal 19) [rear].

NOTE:
Also check intermediate connector D-11 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector D-11 is damaged, repair or replace the connector as described in Harness Connector Inspection Harness Connector Inspection.

- Check the communication line for open circuit.

Q. Are the wiring harness between headlight assembly (RH) connector A-57 (terminal 3)[ front], side turn-signal light (RH) connector A-02 (terminal 2)[ side], rear combination light (RH) connector F-06 (terminal 2)[ rear] and ETACS-ECU connector C-304 (terminal 16)[ front or side] or C-311 (terminal 19)[ rear] in good condition?

YES Go to Step 7.
NO The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.
STEP 7. Using scan tool MB991958, Check whether the diagnostic trouble code is reset.





(1)
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

Connect scan tool MB991958. Refer to "How to connect scan tool Reading and Clearing Diagnostic Trouble Codes."
(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 if DTC is set.

Q. Is the DTC set?

YES Replace the ETACS-ECU.

NO The procedure is complete.