[Previous][Next]
LIN BUS LINE SYSTEM INSPECTION
 
 
 
 
COMMENTS ON TROUBLE SYMPTOM
If the slave ECU does not work normally, the LIN bus line, the slave ECU or the ETACS-ECU may be defective.
 
 
PROBABLE CAUSES
  • The ETACS-ECU may be defective.
  • The slave ECU may be defective.
  • LIN bus lines shorted to power supply
  • LIN bus lines shorted to ground
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Measure the voltage at the LIN bus lines.
Check the LIN bus lines for short to power supply.
(1) Disconnect all the connectors leading to the LIN bus lines.
(2) Turn the ignition switch from "LOCK" (OFF) to "ON" position.
(3) Measure the voltage between the column switch connector (DATA terminal) and the body ground.
  • The voltmeter needle does not swing.
noteIf the LIN bus lines are short to power supply, the voltmeter indicates a constant value.
(4) Measure the voltage between the sunroof motor assembly connector (LIN terminal) and the body ground. <Vehicles with sunroof>
  • The voltmeter needle does not swing.
noteIf the LIN bus lines are short to power supply, the voltmeter indicates a constant value.
(5) Measure the voltage between the lighting control sensor connector (LIN2 terminal) and the body ground.
  • The voltmeter needle does not swing.
noteIf the LIN bus lines are short to power supply, the voltmeter indicates a constant value.
Is the check result normal?
Go to Step 2.
Repair the connector(s) or wiring harness.
 
STEP 2. Measure the resistance at the LIN bus lines.
Check the LIN bus lines for short to ground.
(1) Disconnect all the connectors leading to the LIN bus lines.
(2) Measure the resistance between the column switch connector (DATA terminal) and the body ground.
  • No continuity (1 kΩ or more)
(3) Measure the resistance between the sunroof motor assembly connector (LIN terminal) and the body ground. <Vehicles with sunroof>
  • No continuity (1 kΩ or more)
(4) Measure the resistance between the lighting control sensor connector (LIN2 terminal) and the body ground.
  • No continuity (1 kΩ or more)
Is the check result normal?
Go to Step 3.
Repair the connector(s) or wiring harness.
 
STEP 3. Check the column switch.
Disconnect the column switch connector, and check whether the following DTC are set.
  • U0169 <Vehicles with sunroof>
  • U0231 <Vehicles with lighting control sensor>
(1) Connect all the relevant ECUs, and disconnect column switch connector only.
(2) Erase the DTC.
(3) Turn the ignition switch from "LOCK" (OFF) to "ON" position.
(4) Check whether DTC U0169*1 and U0231*2 are set
note
  • *1: Vehicles with sunroof
  • *2: Vehicles with lighting control sensor
(5) Turn the ignition switch to the "LOCK" (OFF) position.
Is the DTC set?
Reconnect the column switch connector, and go to Step 4 <Vehicles with sunroof>.
Reconnect the column switch connector, and go to Step 5 <Vehicles without sunroof (with lighting control sensor)>.
Reconnect the column switch connector, and go to Step 6 <Vehicles without sunroof and lighting control sensor>.
Replace the column switch (Refer to GROUP 54A - Column switch ).
 
STEP 4. Check the sunroof motor assembly.
Disconnect the sunroof motor assembly connector, and check whether the following DTC are set.
  • U0231 <Vehicles with lighting control sensor>
  • U1109
(1) Connect all the relevant ECUs, and disconnect sunroof motor assembly connector only.
(2) Erase the DTC.
(3) Turn the ignition switch from "LOCK" (OFF) to "ON" position.
(4) Check whether DTC U0231* and U1109 are set
note*: Vehicles with lighting control sensor
(5) Turn the ignition switch to the "LOCK" (OFF) position.
Is the DTC set?
Reconnect the sunroof motor assembly connector, and go to Step 5 <Vehicles with lighting control sensor>.
Reconnect the sunroof motor assembly connector, and go to Step 6 <Vehicles without lighting control sensor>.
Replace the sunroof motor assembly (Refer to GROUP 42A - Sunroof Assembly ).
 
STEP 5. Check the lighting control sensor.
Disconnect lighting control sensor connector, and check whether the following DTC are set.
  • U0169 <Vehicles with sunroof>
  • U1109
(1) Connect all the relevant ECUs, and disconnect lighting control sensor connector only.
(2) Erase the DTC.
(3) Turn the ignition switch from "LOCK" (OFF) to "ON" position.
(4) Check whether DTC U0169* and U1109 are set
note*: Vehicles with sunroof
(5) Turn the ignition switch to the "LOCK" (OFF) position.
Is the DTC set?
Reconnect the lighting control sensor, and go to Step 6.
Replace the lighting control sensor (Refer to GROUP 54A - Lighting Control Sensor ).
 
STEP 6. Recheck for DTC.
Check again if the DTC is set in the ETACS-ECU.
(1) Erase the DTC.
(2) Turn the ignition switch from "LOCK" (OFF) to "ON" position.
(3) Check whether DTC U0215*1, U0231*2 and U1109 are set.
note
  • *1: Vehicles with sunroof
  • *2: Vehicles with lighting control sensor
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the DTC set?
Replace the ETACS-ECU (Refer to GROUP 54A - ETACS-ECU ).
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).