DTC U1515: No-Bus Activity Error (LIN): Diagnosis

WARNING: This page is about a different variant/trim than selected.

Required Special Tools:

MB991223: Harness Set
MB992006: Extra Fine Probe
MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicles Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)

STEP 1. Check the following connectors.
Check the following connectors:
- Column switch connector C-212
- ETACS-ECU connectors C-301 and C-316
- Sunroof motor assembly connector D-06 <Vehicles with sunroof>
- Lighting control sensor connector D-02 <Vehicles with auto light function>
- Power window main switch connector E-15 <Vehicles with central door locking system>
- Theft-alarm sensor connector D-46
- Theft-alarm siren connector A-61
- LIN cutoff control unit connector C-140
Q: Are all the connectors in good condition?
- YES: Go to Step 2.
- NO: Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .

Step 2. Check the LIN cutoff control unit.

Remove the LIN cutoff control unit. Check for continuity between the following terminals and inspect the relay.

Continuity check

CONTINUITY CHECK

Terminal number	Measurement value
5 to 3	Continuity exists (2 ohms or less)

Relay check

RELAY CHECK

Battery voltage	Terminal number	Normal condition
At no energization	5 to 7	No continuity
With current supply [terminal 1 (+), terminal 8 (-)]	5 to 7	Continuity exists (2 ohms or less)

Is the LIN control unit in good condition?

YES : Go to Step 3.
NO : Replace the LIN cutoff control unit

STEP 3. Measure the voltage at the LIN bus lines.
Check the LIN bus lines for short to power supply.
1. Disconnect all the ECU connectors which are connected to the LIN bus lines.
2. Turn the ignition switch from "LOCK" (OFF) to "ON" position.
3. Measure the voltage between column switch connector C-212 (terminal 3) and ground.
  - The voltmeter needle does not swing.
    NOTE: If the LIN bus lines are short to power supply, the voltmeter indicates a constant value.
    
    Fig 1: Measuring Voltage Between Column Switch Connector C-212 Terminal 3 & Ground
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
4. Measure the voltage between power window main switch connector E-15 (terminal 7) and ground.
  - The voltmeter needle does not swing.
    NOTE: If the LIN bus lines are short to power supply, the voltmeter indicates a constant value.
    
    Fig 2: Measuring Voltage Between Power Window Main Switch Connector E-15 Terminal 7 & Ground
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
5. Measure the voltage between sunroof motor assembly connector D-06 (terminal 7) and ground. <Vehicles with sunroof>
  - The voltmeter needle does not swing.
    NOTE: If the LIN bus lines are short to power supply, the voltmeter indicates a constant value.
    
    Fig 3: Measuring Voltage Between Sunroof Motor Assembly Connector D-06 Terminal 7 & Ground
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
6. Measure the voltage between lighting control sensor connector D-02 (terminal 3) and ground. <Vehicles with auto light function>
  - The voltmeter needle does not swing.
    NOTE: If the LIN bus lines are short to power supply, the voltmeter indicates a constant value.
    
    Fig 4: Measuring Voltage Between Lighting Control Sensor Connector D-02 Terminal 3 & Ground
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
7. Measure the voltage between theft alarm sensor connector D-46 (terminal 2) and ground.
  - The voltmeter needle does not swing.
    NOTE: If the LIN bus lines are short to power supply, the voltmeter indicates a constant value.
    
    Fig 5: Measuring Voltage Between Theft Alarm Sensor Connector D-46 Terminal 2 & Ground
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
8. Measure the voltage between theft alarm siren connector A-61 (terminal 3) and ground.
  - The voltmeter needle does not swing.
    NOTE: If the LIN bus lines are short to power supply, the voltmeter indicates a constant value.
    
    Fig 6: Measuring The Voltage Between Theft Alarm Siren Connector A-61 Terminal 3 & Ground
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Q: Is the check result normal?
- YES : Go to Step 4.
- NO : The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.
STEP 4. Measure the resistance at the LIN bus lines.
Check the LIN bus lines for short to ground.
1. Disconnect all the ECU connectors which are connected to the LIN bus lines.
2. Measure the resistance value between column switch connector C-212 (terminal 3) and ground.
  - No continuity (1 kΩ or more)
    
    Fig 7: Measuring Resistance Value Between Column Switch Connector C-212 Terminal 3 & Ground
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
3. Measure the resistance value between power window main switch connector E-15 (terminal 7) and ground.
  - No continuity (1 kΩ or more)
    
    Fig 8: Measuring Resistance Value Between Power Window Main Switch Connector E-15 Terminal 7 & Ground
    Courtesy of MITSUBISHI MOTOR SPORTS OF AMERICA.
4. Measure the resistance value between sunroof motor assembly connector D-06 (terminal 7) and ground. <Vehicles with sunroof>
  - No continuity (1 kΩ or more)
    
    Fig 9: Measuring Resistance Value Between Sunroof Motor Assembly Connector D-06 Terminal 7 & Ground
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
5. Measure the resistance value between lighting control sensor connector D-02 (terminal 3) and ground.
  - No continuity (1 kΩ or more)
    
    Fig 10: Measuring Resistance Value Between Lighting Control Sensor Connector D-02 Terminal 3 & Ground
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
6. Measure the resistance value between theft alarm sensor connector D-46 (terminal 2) and ground.
  - No continuity (1 kΩ or more)
    
    Fig 11: Measuring Resistance Value Between Theft Alarm Sensor Connector D-46 Terminal 2 & Ground
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
7. Measure the resistance value between theft alarm siren connector A-61 (terminal 3) and ground.
  - No continuity (1 kΩ or more)
    
    Fig 12: Measuring Resistance Value Between Theft Alarm Siren Connector A-61 Terminal 3 & Ground
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Q: Is the check result normal?
- YES : Go to Step 5.
- NO : The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.
STEP 5. Check the column switch.
Disconnect column switch connector C-212, and recheck whether DTC U1515 is set.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect scan tool MB991958. Refer to "HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ."
2. Connect all the relevant ECUs, and disconnect column switch connector C-212 only.
3. Erase the DTC.
4. Turn the ignition switch from "LOCK" (OFF) to "ON" position.
5. Check whether DTC U1515 is set.
  NOTE: If DTC U1515 is not set, DTC U1109 is set because the column switch is disconnected. This is normal.
6. Turn the ignition switch to the "LOCK" (OFF) position.
  Q: Is DTC U1515 set?
  - YES: Reconnect the column switch connector, and go to Step 6.
  - NO: Replace the column switch.
    
    Fig 13: Connecting Scan Tool To Data Link Connector
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 6. Check the power window main switch.
Disconnect power window main switch connector E-15, and recheck whether DTC U1515 is set.
1. Connect all the relevant ECUs, and disconnect power window main switch connector E-15 only.
2. Erase the DTC.
3. Turn the ignition switch from "LOCK" (OFF) to "ON" position.
4. Check whether DTC U1515 is set.
  NOTE: If DTC U1515 is not set, DTC U0215 is set because the power window main switch is disconnected. This is normal.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC U1515 set?
- YES : Reconnect the power window main switch connector, and go to Step 7.
- NO : Replace the power window main switch.
STEP 7. Check the sunroof motor assembly.
Disconnect sunroof motor assembly connector D-06, and recheck whether DTC U1515 is set.
1. Connect all the relevant ECUs, and disconnect sunroof motor assembly connector D-06 only.
2. Erase the DTC.
3. Turn the ignition switch from "LOCK" (OFF) to "ON" position.
4. Check whether DTC U1515 is set.
  NOTE: If DTC U1515 is not set, DTC U0169 is set because the sunroof motor assembly is disconnected. This is normal.
5. Turn the ignition switch to the "LOCK" (OFF) position.
  Q: Is DTC U1515 set?
  - YES: Reconnect the sunroof motor assembly connector, and go to Step 8.
  - NO: Replace the sunroof motor assembly.
STEP 8. Check the lighting control sensor.
Disconnect lighting control sensor connector D-02, and recheck whether DTC U1515 is set.
1. Connect all the relevant ECUs, and disconnect lighting control sensor connector D-02 only.
2. Erase the DTC.
3. Turn the ignition switch from "LOCK" (OFF) to "ON" position.
4. Check whether DTC U1515 is set.
  NOTE: If DTC U1515 is not set, DTC U0231 is set because the power lighting control sensor is disconnected. This is normal.
5. Turn the ignition switch to the "LOCK" (OFF) position.
  Q: Is DTC U1515 set?
  - YES: Reconnect the lighting control sensor connector, and go to Step 9.
  - NO: Replace the lighting control sensor.
STEP 9. Check the theft-alarm sensor.
Disconnect theft-alarm sensor connector D-46, and recheck whether DTC U1515 is set.
1. Connect all the relevant ECUs, and disconnect theft-alarm sensor connector D-46 only.
2. Erase the DTC.
3. Turn the ignition switch from "LOCK" (OFF) to "ON" position.
4. Check whether DTC U1515 is set.
  NOTE: If DTC U1515 is not set, DTC U1007 is set because the theft-alarm sensor is disconnected. This is normal.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC U1515 set?
1. YES : Reconnect the theft-alarm sensor connector, and go to Step 10.
2. NO : Replace the theft-alarm sensor.
STEP 10. Check the theft-alarm siren.
Disconnect theft-alarm siren connector A-61, and recheck whether DTC U1515 is set.
1. Connect all the relevant ECUs, and disconnect theft-alarm siren connector A-61 only.
2. Erase the DTC.
3. Turn the ignition switch from "LOCK" (OFF) to "ON" position.
4. Check whether DTC U1515 is set.
  NOTE: If DTC U1515 is not set, DTC U1006 is set because the theft-alarm siren is disconnected. This is normal.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC U1515 set?
- YES : Reconnect the theft-alarm siren connector, and go to Step 11.
- NO : Replace the theft-alarm siren.
STEP 11. Recheck for diagnostic trouble code.
Check again if the DTC is set to the ETACS-ECU.
1. Erase the DTC.
2. Turn the ignition switch from "LOCK" (OFF) to "ON" position.
3. Check whether DTC U1515 is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.
  Q: Is the DTC set?
  - YES: Replace the ETACS-ECU.
  - NO: The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).