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DTC B16A4: Turn signal(RH) bulb outage
 
 
cautionBefore replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
 
 
DIAGNOSTIC FUNCTION
When the right bulb of turn-signal light is blown, the ETACS-ECU sets DTC No. B16A4.
 
 
DTC SET CONDITION
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," the 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
  • 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-signal light: RH) connector, door mirror assembly (LH) connector and rear combination light (turn-signal light: 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-signal light: 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-signal light: 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-signal light: RH) connector, door mirror assembly (RH) connector or rear combination light (turn-signal light: 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-signal light: 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-signal light: 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. Check whether the DTC is set again.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn off the power supply mode of the electric motor switch before connecting or disconnecting scan tool (M.U.T.-IIISE).
Connect scan tool (M.U.T.-IIISE). Refer to "How to connect Scan Tool (M.U.T.-IIISE) ."
(2) Erase the DTC.
(3) Press the electric motor switch to turn the power supply mode from "OFF" to "ON."
(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 ).