DTC U1515: No-Bus activity error (LIN): Diagnosis

WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.

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 >
- Power window main switch connector E-15
- Lighting control sensor connector D-02 < Vehicles with auto light function >
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 following wiring harness.
Check the wiring harness between the following connectors:
- Wiring harness from ETACS-ECU connector C-301 (terminal 1) to column switch connector C-212 (terminal 3)
- Wiring harness from ETACS-ECU connector C-316 (terminal 1) to sunroof motor assembly connector D-06 (terminal 7)
- Wiring harness from ETACS-ECU connector C-301 (terminal 1) to power window main switch connector E-15 (terminal 7)
- Wiring harness from ETACS-ECU connector C-316 (terminal 1) to lighting control sensor connector D-02 (terminal 3)
NOTE: Also check joint connector C-102 and intermediate connector C-129 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If joint connector C-102 or intermediate connector C-129 is damaged, repair or replace the connector as described in HARNESS CONNECTOR INSPECTION .

Q: Are all the wiring harness wires in good condition?

YES : Go to Step 3.

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 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.
  
  Fig 1: Measuring Voltage Between Column Switch Connector C-212 (Terminal 3) And Ground
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  - The voltmeter needle does not swing.
    NOTE: If the LIN bus lines are short to power supply, the voltmeter indicates a constant value.
4. Measure the voltage between sunroof motor assembly connector D-06 (terminal 7) and ground.
  
  Fig 2: Measuring Voltage Between Sunroof Motor Assembly Connector D-06 (Terminal 7) And Ground
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  - The voltmeter needle does not swing.
    NOTE: If the LIN bus lines are short to power supply, the voltmeter indicates a constant value.
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 3: Measuring Resistance Value Between Column Switch Connector C-212 (Terminal 3) And Ground
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
3. Measure the resistance value between sunroof motor assembly connector D-06 (terminal 7) and ground.
  
  Fig 4: Measuring Resistance Value Between Sunroof Motor Assembly Connector D-06 (Terminal 7) And Ground
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  - No continuity (1 kΩ or more)
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) ".
  
  Fig 5: Connecting Special Tool To Data Link Connector
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
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.
STEP 6. 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 7.

NO : Replace the sunroof motor assembly.
STEP 7. 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 8.

NO : Replace the power window main switch.
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. 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 ).