[Previous][Next]
DTC B16A7: Taillight (RH) circuit short <Short circuit in the position light (RH) circuit or the taillight (RH) circuit>
cautionBefore replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
 
 
DIAGNOSTIC FUNCTION
When a short circuit is detected in the following circuit, the ETACS-ECU sets DTC No. B16A7.
  • Taillight
  • Side marker light
  • Position light
  • Glove box light
  • Floor console box light <Vehicles with floor console box light>
 
 
TROUBLE JUDGMENT
The problem detection of each light is made based on the digital feed back signal (input signal to ETACS-ECU) which operates the each light. When the ignition switch is ON, the ETACS-ECU determines the each 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 DTC No. B16A7 if no load is detected.
 
 
TROUBLESHOOTING HINTS
  • The rear combination light unit (RH) may be defective
  • The side marker light bulb (front RH) may be defective
  • The headlight body may be defective
  • The taillight assembly (RH) may be defective
  • The floor console box light may be defective <Vehicles with floor console box light>
  • 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
  • The ETACS-ECU may be defective
 
 
DIAGNOSIS
Required Special Tools:
  • MB992006: Extra fine probe
  • MB991223: Harness set
STEP 1. Resistance measurement at the rear connector (ground terminals).
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Measure the resistance between the rear combination light (tail/side marker: RH) connector (ground terminal) and ground.
OK: The resistance should be 2 ohms or less
Is the check result normal?
Go to Step 3.
Go to Step 2.
 
STEP 2. Check of open circuit in ground lines between the rear combination light (tail/side maker: RH) connector and ground.
Is the check result normal?
Go to Step 3.
Repair the connector(s) or wiring harness. then go to Step 3.
 
STEP 3. Check of short to power supply and open circuit in power supply lines between the rear combination light (tail/side marker: RH) connector and ETACS-ECU connector.
Is the check result normal?
Go to Step 4.
Repair the connector(s) or wiring harness. Then go to Step 4.
 
STEP 4. 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?
Go to Step 5.
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
 
STEP 5. Substitute a known good headlight assembly (RH), and check the DTC.
(1) Erase the DTC.
(2) Press the electric motor switch to turn the power supply mode from "OFF" to "ON."
(3) Check if DTC is set.
Is the DTC set?
Go to Step 6.
Replace the headlight assembly (RH).
 
STEP 6. Check the rear combination light socket.
Check the continuity at the side marker light bulb (RH) to confirm whether it is normal.
Is the check result normal?
Go to Step 7.
Replace the rear combination light socket (RH). Then go to Step 7.
 
STEP 7. Resistance measurement at the rear combination light (taillight/side marker light: RH) connector (ground terminal).
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Measure the resistance between the rear combination light (taillight/side marker light: RH) connector (ground terminal) and ground.
OK: The resistance should be 2 ohms or less
Is the check result normal?
Go to Step 10.
Go to Step 8.
 
STEP 8. Check of open circuit in ground line between the rear combination light (taillight/side marker light: RH) connector and ground
Is the check result normal?
Go to Step 9.
Repair the connector(s) or wiring harness.
 
STEP 9. Check of short to power supply, short to ground, and open circuit in TAR2 line between the rear combination light (taillight/side marker light: RH) connector and ETACS-ECU connector.
Is the check result normal?
Go to Step 10.
Repair the connector(s) or wiring harness.
 
STEP 10. 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?
Go to Step 11.
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
 
STEP 11. Substitute a known good rear combination light assembly (RH), and check the DTC.
(1) Erase the DTC.
(2) Press the electric motor switch to turn the power supply mode from "OFF" to "ON."
(3) Check if DTC is set.
Is the DTC set?
Go to Step 12.
Replace the rear combination light assembly (RH).
 
STEP 12. Resistance measurement at the taillight (RH) connector (ground terminal).
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Measure the resistance between the taillight (RH) connector (ground terminal) and the ground.
OK: The resistance should be 2 ohms or less
Is the check result normal?
Go to Step 14.
Go to Step 13.
 
STEP 13. Check of open circuit in ground lines between the taillight (RH) connector and ground.
Is the check result normal?
Go to Step 14.
Repair the connector(s) or wiring harness. Then go to Step 14.
 
STEP 14. Check of short to power supply, short to ground, and open circuit in TAR2 line between the taillight (RH) connector and ETACS-ECU connector.
Is the check result normal?
Go to Step 15.
Repair the connector(s) or wiring harness. Then go to Step 15.
 
STEP 15. Substitute a known good taillight assembly (RH), and check the DTC.
(1) Erase the DTC.
(2) Press the electric motor switch to turn the power supply mode from "OFF" to "ON."
(3) Check if DTC is set.
Is the DTC set?
Go to Step 16.
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
 
STEP 16. Substitute a known good taillight assembly (RH), and check the DTC.
(1) Erase the DTC.
(2) Press the electric motor switch to turn the power supply mode from "OFF" to "ON."
(3) Check if DTC is set.
Is the DTC set?
Go to Step 17
Replace the taillight assembly (RH).
 
STEP 17. Check the glove box light bulb.
Check the continuity at the glove box light bulb to confirm whether it is normal.
Is the DTC set?
Go to Step 18.
Replace the glove box light bulb. Then go to Step 18
 
STEP 18. Check of short to power supply and open circuit in power supply lines between the glove box light connector and ETACS-ECU connector.
Is the check result normal?
Go to Step 19.
Repair the connector(s) or wiring harness. Then go to Step 19 .
 
STEP 19. Check of open circuit in ground lines between the glove box light connector and ground.
Is the check result normal?
Go to Step 20
Replace the taillight assembly (RH). Then go to Step 20 .
 
STEP 20. Check whether the DTC is set again.
(1) Erase the DTC.
(2) Press the electric motor switch to turn the power supply mode from "OFF" to "ON."
(3) Check if DTC is set.
Is the DTC set?
: Go to Step 21
: Go to Step 25
The trouble can bean intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/ inspection Service Points - How to Cope with Intermittent Malfunction ).
 
STEP 21. Check the continuity of the floor console box light.
Refer to floor console box light inspection.
Is the check result normal?
Go to Step 22.
Replace the floor console box light. Then go to Step 22.
 
STEP 22. Substitute a known good taillight assembly (RH), and check the DTC.
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Measure the resistance between the floor console box light connector (ground terminal) and ground.
OK: The resistance should be 2 ohms or less
Is the check result normal?
Go to Step 24
Go to Step 23.
 
STEP 23. Check of open circuit in ground lines between the floor console box light connector and ground.
Is the check result normal?
Go to Step 24.
Replace the connector(s) or wiring harness. Then go to Step 24.
 
STEP 24. Check of short to power supply and open circuit in (TAR3) lines between the floor console box light connector and ETACS-ECU connector.
Is the DTC set?
Go to Step 25.
Replace the connector(s) or wiring harness. then go to Step 25.
 
STEP 25. Check whether the DTC is set again.
(1) Erase the DTC.
(2) Press the electric motor switch to turn the power supply mode from "OFF" to "ON."
(3) 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 .