B16A8
DTC B16A8: Taillight
(LH) circuit short (Short circuit in rear side marker light (LH), taillight (LH), position light
(LH), or license plate light)
TROUBLE JUDGMENT
When a short circuit is detected in the position lamp circuit, the tail lamp circuit or the license plate lamp circuit, the ETACS-ECU sets the diagnosis code No. B16A8.
TECHNICAL DESCRIPTION (COMMENT)
The problem detection of tail lamp is made based on the digital feed back signal (input signal to ETACS-ECU) which operates the tail lamp. When the ignition switch is ON, the ETACS-ECU determines the tail lamp circuit state from the load placed on the line. After 100 ms has elapsed since the start of the check, the ETACS-ECU performs a sampling with each 10 ms. If an abnormality is detected, it increases the counter by 2, and when no abnormality is detected, it decreases the counter by 1. Once the counter reaches "10," the ETACS-ECU sets the diagnosis code No. B16A8 if no load is detected.
TROUBLESHOOTING HINTS
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
- Malfunction of bulbs
- Malfunction of the ETACS-ECU
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. Bulb check.
Check the bulb(s) of the light that does not illuminate.
Q. Is the check result normal?
YES Go to Step 2.
NO Replace the bulb(s) of the light that does not illuminate.
STEP 2. Check headlight assembly (LH) connector A-40, rear combination light (LH) connector F-25, rear side marker light (LH) connector F-24, license plate light connector F-18 (LH) and F-15 (RH) for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q. Is headlight assembly (LH) connector A-40, rear combination light (LH) connector F-25, rear side marker light (LH) connector F-24, license plate light connector F-18 (LH) and F-15 (RH) 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 (LH) connector A-40, rear combination light (LH) connector F-25, rear side marker light (LH) connector F-24, license plate light connector F-18 (LH) and F-15 (RH).
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the resistance between the connector of light which does not illuminate and the body ground.
- Measure the resistance between headlight assembly (LH) connector A-40 (terminal 6) and the body ground.
- Measure the resistance between rear combination light (LH) connector F-25 (terminal 1) and the body ground.
- Measure the resistance between rear side marker light (LH) connector F-24 (terminal 1) and the body ground.
- Measure the resistance between license plate light (LH) connector F-18 (terminal 1) and the body ground.
- Measure the resistance between license plate light (RH) connector F-15 (terminal 1) and the body ground.
OK: The measured value should be continuity exists (2ohms 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 connector, rear combination light connector, tail light connector or license plate light and the body ground.
Check the ground line for open circuit.
- Check the wiring harness between headlight assembly (LH) connector A-40 (terminal 6) and the body ground.
- Check the wiring harness between rear combination light (LH) connector F-25 (terminal 1) and the body ground.
- Check the wiring harness between rear side marker light (LH) connector F-24 (terminal 1) and the body ground.
NOTE:
Also check intermediate connector F-27 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector F-27 is damaged, repair or replace the connector as described in Harness Connector Inspection Harness Connector Inspection .
- Check the wiring harness between license plate light (LH) connector F-18 (terminal 1) and the body ground.
- Check the wiring harness between license plate light (RH) connector F-15 (terminal 1) and the body ground.
Q. Is the wiring harness between headlight assembly connector, rear combination light connector, tail light connector or license plate light and the body 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 [position light] and C-311 [rear side marker light, taillight or license plate light] for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q. Is ETACS-ECU connectors C-304[ position light] and C-311[ rear side marker light, taillight or license plate light] in good condition?
YES Go to Step 6.
NO Repair or replace the damaged component(s). Harness Connector Inspection.
STEP 6. Check wiring harness between headlight assembly connector, rear combination light connector, rear side marker light connector or license plate light and ETACS-ECU connector.
Check the power supply line for open circuit or short circuit.
- Check the wiring harness between headlight assembly (LH) connector A-40 (terminal 4) and ETACS-ECU connector C-304 (terminal 3).
- Check the wiring harness between rear combination light (LH) connector F-25 (terminal 3) and ETACS-ECU connector C-311 (terminal 10).
NOTE:
Also check intermediate connectors 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 Harness Connector Inspection Harness Connector Inspection .
- Check the wiring harness between rear side marker light (LH) connector F-24 (terminal 2) and ETACS-ECU connector C-311 (terminal 10).
NOTE:
Also check intermediate connectors D-17 and F-27 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector D-17 or F-27 is damaged, repair or replace the connector as described in Harness Connector Inspection Harness Connector Inspection .
- Check the wiring harness between license plate light (LH) connector F-18 (terminal 2) and ETACS-ECU connector C-311 (terminal 10).
NOTE:
Also check intermediate connectors 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 Harness Connector Inspection Harness Connector Inspection .
- Check the wiring harness between license plate light (RH) connector F-15 (terminal 2) and ETACS-ECU connector C-311 (terminal 10).
NOTE:
Also check intermediate connectors 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 Harness Connector Inspection Harness Connector Inspection .
Q. Is the wiring harness between headlight assembly connector, rear combination light connector, rear side marker light connector or license plate light and ETACS-ECU connector 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 (M.U.T.-III) 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.