Inspection Procedure K-1: The tail/stop lamps do not illuminate normally.


caution Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.


COMMENTS ON TROUBLE SYMPTOM
If all the tail/stop lamps do not illuminate, the tail lamp switch input circuit or the front-ECU may be defective.

POSSIBLE CAUSES

  • Malfunction of the column switch
  • Malfunction of the front-ECU
  • Damaged harness wires and connectors

DIAGNOSTIC PROCEDURE

Step 1. Pulse check
Check the input signal from the tail lamp switch.
System switch
 Check condition
Ignition switch (IG1)
 When turned from ACC to ON
Tail lamp switch
 When the lighting switch is turned to the TAIL position
OK: The M.U.T.-III sounds or the voltmeter needle fluctuates.

Q. Is the check result normal?
All the signals are received normally. : Go to Step 2.
The ignition switch (IG1) signal is not received. : Refer to Inspection Procedure P-2 "The ignition switch (IG1) signal is not received ."
The tail lamp switch signal is not received. : Refer to Inspection Procedure P-5 "The column switch (lighting and turn-signal lamp) signal is not received ."

Step 2. Connector check: A-14X front-ECU connector.

Q. Is the check result normal?

Go to Step 3.

Repair the defective connector.

Step 3. Voltage measurement at the A-14X front-ECU connector.

(1)Remove the front-ECU, and measure at the relay box side.

(2)Voltage between A-14X front-ECU connector terminal No.5 and body earth
OK: System voltage

Q. Is the check result normal?

Go to Step 5.

Go to Step 4.

Step 4. Check the wiring harness between A-14X front-ECU connector terminal No.5 to the fusible link (26).


  • Check the power supply line for open circuit.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

Repair the wiring harness.

Step 5. Retest the system.
Check that the tail/stop lamps illuminate normally.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Replace the front-ECU.