Code No.U1504: Lighting control sensor LIN timeout <Vehicles with auto lamp>


note When the diagnosis codes relating to the LIN communication error are set, make sure of the vehicle equipment. When the vehicle is not equipped with the system the ETACS-ECU communicates to, the diagnosis code is always set. This is not abnormal.


TROUBLE JUDGEMENT



COMMENT ON TROUBLE SYMPTOM


The M.U.T.-III shows a diagnosis code status as active.
  • Connector(s) or wiring harness in the LIN bus lines between the lighting control sensor and the ETACS-ECU, the power supply system of the lighting control sensor, or the lighting control sensor itself may be defective.
The M.U.T.-III shows a diagnosis code status as stored.
  • If diagnosis code No.U1504 is stored as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s) in the LIN bus line between the lighting control sensor and the ETACS-ECU, and the power supply system of the lighting control sensor. For diagnosis procedures, refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Treat Past Trouble .

PROBABLE CAUSES



  • Malfunction of the lighting control sensor
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-206 junction block connector, C-219 ETACS-ECU connector, D-38 lighting control sensor connector



Q. Is the check result normal?

Go to Step 2.

Repair the defective connector. Go to Step 7.

STEP 2. Resistance measurement at the D-38 lighting control sensor connector


(1)Disconnect the connector, and measure at the wiring harness side.

(2)Measure the resistance between the D-38 lighting control sensor connector terminal No. 2 and the body earth.
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 4.

Go to Step 3.

STEP 3. Check the wiring harness between D-38 lighting control sensor connector terminal No. 2 to body earth


Check the earth wires for open circuit.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).

Repair the wiring harness.

STEP 4. Voltage measurement at the D-38 lighting control sensor connector.


(1)Disconnect the connector, and measure at the wiring harness side.

(2)Measure the voltage between the D-38 lighting control sensor connector terminal No. 1 and the body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 6.

Go to Step 5.

STEP 5. Check the wiring harness between C-206 junction block connector terminal No. 3 and D-38 lighting control sensor connector terminal No. 1



Check the power supply line for open circuit and short circuit.

Q. Is the check result normal?

The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).

Repair the wiring harness.

STEP 6. Check the wiring harness between C-219 ETACS-ECU connector terminal No. 54 and D-38 lighting control sensor connector terminal No. 3.



Check the communication lines for open circuit.


note Prior to the wiring harness inspection, check joint connector C-138 and intermediate connector C-117, and repair if necessary.

Q. Is the check result normal?

Go to Step 7.

Repair the wiring harness. Go to Step 7.

STEP 7. Check whether the diagnosis code is reset.
Check again if the diagnosis code is set to the ETACS-ECU.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3)Check if diagnosis code is set.

Q. Is the diagnosis code set?
Replace the lighting control sensor.
A poor connection, open circuit or other intermittent malfunction is present in the LIN bus lines between the lighting control sensor and the ETACS-ECU (Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).