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DTC U1500: Column ECU LIN timeout/Not equip
 
 
cautionWhenever the ECU is replaced, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
JUDGMENT CRITERIA
The ETACS-ECU will store DTC No. U1500 when no signals are received from the column switch (column-ECU).
 
 
TROUBLESHOOTING HINTS
  • The lighting switch 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:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Resistance measurement at the column switch connector
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Measure the resistance between the column switch connector (GND terminal) and the 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 GND line between column switch connector and ground
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 connector(s) or wiring harness.
 
STEP 3. Voltage measurement at the column switch connector.
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Measure the voltage between the column switch connector (+B terminal) and the ground.
OK: The voltage should measure approximately 12 volts (battery positive voltage).
Is the check result normal?
Go to Step 5.
Go to Step 4.
 
STEP 4. Check of short to power supply, and open circuit in +B line between column switch connector and junction block connector.
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 connector(s) or wiring harness.
 
STEP 5. Check of open circuit in LIN line between ETACS-ECU connector and column switch connector.
Is the check result normal?
Go to Step 6.
Repair the connector(s) or wiring harness.
 
STEP 6. Recheck for diagnostic trouble code.
Check again if the DTC is stored in the ETACS-ECU.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III). Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(2) Erase the DTC.
(3) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(4) Check if DTC is stored.
Is the DTC stored?
Replace the lighting switch.
A poor connection, open circuit, or other intermittent malfunctions in the LIN bus lines between the column switch and the ETACS-ECU (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).