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DTC B16A3: Turn-signal light (LH) short circuit












TROUBLE JUDGMENT


When the left wiring harness of turn-signal light is short circuited, the ETACS-ECU sets DTC B16A3.

TECHNICAL DESCRIPTION (COMMENT)


When the short circuit is detected three times consecutively, the ETACS-ECU sets the DTC B16A3.

TROUBLESHOOTING HINTS



DIAGNOSIS
Required Special Tools:
  • MB992006: Extra fine probe
  • MB991223: Harness set
  • 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. 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?
Go to Step 2.
NO : Repair or replace the damaged component(s). Refer to GROUP 00E, Harness Connector Inspection .

STEP 2. 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?
Go to Step 3.
Replace the bulb(s) of the light that does not illuminate.

STEP 3. 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 as described in GROUP 00E, Harness Connector Inspection .

  • 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?
Go to Step 4.
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 4. 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 ."
(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?

Replace the ETACS-ECU.

The procedure is complete.