FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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B16A7

DTC B16A0: Taillight (RH) Circuit Open (Open Circuit In Rear Side Marker Light (RH), Taillight (RH) Or Position Light (RH))
DTC B16A7: Taillight (RH) Circuit Short (Short Circuit In Rear Side Marker Light (RH), Taillight (RH) Or Position Light (RH))


Taillight And Position Light Circuit (Part 1):




Taillight And Position Light Circuit (Part 2):






TROUBLE JUDGMENT
When an open circuit is detected in the rear side marker light, taillight or position light circuit, the ETACS-ECU sets DTC B16A0. If a short circuit is detected, DTC B16A7 is set.

TECHNICAL DESCRIPTION (COMMENT)
The problem detection of rear side marker light, taillight or position light is made based on the digital feed back signal (input signal to ETACS-ECU) which operates the rear side marker light, taillight or position light. When the ignition switch is "ON", the ETACS-ECU determines the rear side marker light, taillight or position light 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 DTC B16A0 if the load is detected on the line, and sets the DTC B16A7 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 (RH) connector A-57, rear combination light (RH) connector F-06 and rear side marker light (RH) connector F-07 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is headlight assembly (RH) connector A-57, rear combination light (RH) connector F-06 and rear side marker light (RH) connector F-07 in good condition?

YES : Go to Step 3.

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

STEP 3. Resistance measurement at headlight assembly (RH) connector A-57, rear combination light (RH) connector F-06 and rear side marker light (RH) connector F-07.

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 (RH) connector A-57 (terminal 6) and the body ground.







- Measure the resistance between rear combination light (RH) connector F-06 (terminal 1) and the body ground.







- Measure the resistance between rear side marker light (RH) connector F-07 (terminal 1) and the body ground.

OK: The measured value should be continuity exists (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 connector, rear combination light connector or tail light connector and the body ground.

Check the ground line for open circuit.
- Check the wiring harness between headlight assembly (RH) connector A-57 (terminal 6) and the body ground.
- Check the wiring harness between rear combination light (RH) connector F-06 (terminal 1) and the body ground.
- Check the wiring harness between rear side marker light (RH) connector F-07 (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.

Q: Is the wiring harness between headlight assembly connector, rear combination light connector or tail light connector 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 or taillight] 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 or taillight] in good condition?

YES : Go to Step 6.

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

STEP 6. Check wiring harness between headlight assembly connector, rear combination light connector and rear side marker light connector and ETACS-ECU connector.

Check the power supply line for open circuit or short circuit.
- Check the wiring harness between headlight assembly (RH) connector A-57 (terminal 4) and ETACS-ECU connector C-304 (terminal 7).
- Check the wiring harness between rear combination light (RH) connector F-06 (terminal 3) and ETACS-ECU connector C-311 (terminal 13).

NOTE: Also check intermediate connectors D-11 and joint connector C-43 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector D-11 or joint connector C-43 is damaged, repair or replace the connector.

- Check the wiring harness between rear side marker light (RH) connector F-07 (terminal 2) and ETACS-ECU connector C-311 (terminal 13).

NOTE: Also check intermediate connectors D-17 and F-27 and joint connector C-43 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector D-17 or F-27 or joint connector C-43 is damaged, repair or replace the connector.

Q: Is the wiring harness between headlight assembly connector, rear combination light connector or rear side marker light connector 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.

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 (M.U.T.-III)." 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 if DTC is set.

Q: Is the DTC set?

YES : Replace the ETACS-ECU.

NO : The procedure is complete.