B16A2

DTC B16A2: Blown Turn-Signal Light (LH) Bulb

Turn-Signal Lights(LH) Circuit:

TROUBLE JUDGMENT
When the left bulb of turn-signal light is blown, the ETACS-ECU sets DTC B16A2.

TECHNICAL DESCRIPTION (COMMENT)
The ETACS-ECU sets DTC B16A2 under the following conditions.
- If there is a malfunction to the left turn-signal light bulb, the blown left bulb counter counts once when the illumination of hazard or turn-signal light (left side) is attempted.
- After the bulb counter reaches "3," DTC B16A2 is set.

TROUBLESHOOTING HINTS
- Malfunction of turn-signal light bulb (left)
- 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 left turn-signal light illuminates normally.

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 (LH) connector A-40 [front], side turn-signal light (LH) connector A-12 [side], rear combination light (LH) connector F-25 [rear] for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Are headlight assembly (LH) connector A-40 [front], side turn-signal light (LH) connector A-12 [side], rear combination light (LH) connector F-25 [rear] in good condition?

YES : Go to Step 3.

NO : Repair or replace the damaged component(s).

STEP 3. Resistance measurement at headlight assembly (LH) connector A-40 [front], side turn-signal light (LH) connector A-12 [side], and rear combination light (LH) connector F-25 [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 ground.







- Measure the resistance between the headlight assembly (LH) connector A-40 (terminal 6) and body ground. [Front]







- Measure the resistance between side turn-signal light (LH) connector A-12 (terminal 1) and body ground. [Side]







- Measure the resistance between rear combination light (LH) connector F-25 (terminal 1) and body ground. [Rear]

OK: The measured value should be 2 ohms 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 (LH) connector A-40 (terminal 6) [front], side turn-signal light (LH) connector A-12 (terminal 1) [side], rear combination light (LH) connector F-25 (terminal 1) [rear] and ground.

- Check the ground wires for open circuit.

Q: Are the wiring harness between headlight assembly (LH) connector A-40 (terminal 6) [front], side turn-signal light (LH) connector A-12 (terminal 1) [side], rear combination light (LH) connector F-25 (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. Verify that the headlights illuminate normally.

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 [front or side] and C-311 [rear] in good condition?

YES : Go to Step 6.

NO : Replace the bulb(s) of the light that does not illuminate.

STEP 6. Check the wiring harness between headlight assembly (LH) connector A-40 (terminal 3) [front], side turn-signal light (LH) connector A-12 (terminal 2) [side], rear combination light (LH) connector F-25 (terminal 2) [rear] and ETACS-ECU connector C-304 (terminal 9) [front or side] or C-311 (terminal 18) [rear].

NOTE: Also check intermediate connector D-17 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector D-17 is damaged, repair or replace the connector.

- Check the communication line for open circuit.

Q: Are the wiring harness between headlight assembly (LH) connector A-40 (terminal 3) [front], side turn-signal light (LH) connector A-12 (terminal 2) [side], rear combination light (LH) connector F-25 (terminal 2) [rear] and ETACS-ECU connector C-304 (terminal 9) [front or side] or C-311 (terminal 18) [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. Verify that the headlights illuminate normally.

STEP 7. Using scan tool MB991958, Check whether the diagnostic trouble code is reset.

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.







1. Connect scan tool MB991958. Refer to "How to connect scan tool." How to Connect the 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.

Q: Is the DTC set?

YES : Replace the ETACS-ECU.

NO : The procedure is complete.