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DTC B16A4: Turn signal(RH) bulb outage
 
 
caution
  • Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
  • When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition key needs to be registered to the ETACS-ECU. (If the encrypted code is not registered, the engine cannot be started. Register the encrypted code as described in Immobilizer System - How to Register Key ID .)
 
 
 
 
DIAGNOSTIC FUNCTION
When the right bulb of turn-signal light is blown, the ETACS-ECU sets DTC No. B16A4.
 
 
TROUBLE JUDGMENT
The ETACS-ECU sets DTC No. B16A4 under the following conditions.
  1. With the DTC not set, 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.
  2. If the blown right bulb counter reaches "3," DTC No. B16A4 is set.
 
 
TROUBLESHOOTING HINTS
  • The front or rear turn-signal light bulb (right side) may be defective
  • The side turn-signal light assembly (right side) may be defective <Integrated in door mirror type>
  • The ETACS-ECU may be defective
  • The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
 
 
DIAGNOSIS
Required Special Tools:
  • MB992006: Extra fine probe
  • MB991223: Harness set
STEP 1. Bulb check.
Check whether the bulb of turn-signal light which does not illuminate is normal.
Is the check result normal?
Go to Step 2.
Replace the bulb of turn-signal light which does not illuminate.
 
STEP 2. Resistance measurement at the headlight assembly (TURN: RH) connector, door mirror assembly (RH) connector and rear combination light (TURN: RH) connector.
(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 (TURN: RH) connector (ground terminal) and ground.
  • Measure the resistance between the door mirror assembly (RH) connector (ground terminal) and ground.
  • Measure the resistance between the rear combination light (TURN: RH) connector (ground terminal) and ground.
OK: The resistance should be 2 ohms or less
Is the check result normal?
Go to Step 4.
Go to Step 3.
 
STEP 3. Check of open circuit in ground line between headlight assembly (TURN: RH) connector, door mirror assembly (RH) connector or rear combination light (TURN: RH) connector and ground.
Is the check result normal?
Go to Step 7.
Repair the connector(s) or wiring harness.
 
STEP 4. Check of open circuit in TR1 line between ETACS-ECU connector and headlight assembly (TURN: RH) connector.
Is the check result normal?
Go to Step 5.
Repair the connector(s) or wiring harness.
 
STEP 5. Check of open circuit in TR3 line between ETACS-ECU connector and rear combination light (TURN: RH) connector.
Is the check result normal?
Go to Step 6.
Repair the connector(s) or wiring harness.
 
STEP 6. Check of open circuit in TR2 line between ETACS-ECU connector and door mirror assembly (RH) connector.
Is the check result normal?
Go to Step 7.
Repair the connector(s) or wiring harness.
 
STEP 7. Using scan tool (M.U.T.-III), Check whether the diagnostic trouble code is set again.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III). Refer to "How to connect Scan Tool (M.U.T.-III) ."
(2) Erase the DTC.
(3) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(4) Check if DTC is set.
Is the DTC set?
Replace the ETACS-ECU.
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).