Inspection Procedure 1: Heated seats does not work: Diagnosis

Q: Does the rear window defogger work normally? 

• YES:  Go to Step 2.
• NO:  Carry out the troubleshooting for the rear window defogger. (Refer to TROUBLE SYMPTOM CHART .)

Q: Is heated seat relay connector B-316 in good condition? 

• YES:  Go to Step 3.
• NO:  Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION . Verify that the power window works normally.

Check the heated seat relay.

Q: Does the power window relay work normally? 

• YES:  Go to Step 4.
• NO:  Replace the heated seat relay. Verify that the heated seat works normally.
  Fig 1: Identifying Heated Seat Relay With Connector Terminals

  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

1. Disconnect heated seat relay connector B-316 and measure the resistance available at the wiring harness side of the connector.
2. Measure the resistance value between terminal 2 and ground.
   • The resistance should be 2 ohms or less.

Q: Is the measured resistance 2 ohms or less? 

• YES:  Go to  Step 6.
• NO:  Go to Step 5.
  Fig 2: Measuring Resistance Between Heated Seat Relay Connector B-316 Terminal 2 And Ground

  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

• Check the ground line for open circuit and short circuit.

Q: Is the wiring harness between heated seat relay connector B-316 (terminal 2) and ground in good condition? 

• YES:  No action is necessary and testing is complete.
• 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. Check that the power window works normally.

1. Disconnect heated seat relay connector B-316 and measure the voltage available at the wiring harness side of the connector.
2. Turn the electric motor switch to the "ON" position.
3. Measure the voltage between terminal 1 and ground.
   • The voltage should measure approximately 12 volts (battery positive voltage).

Q: Is the measured voltage approximately 12 volts (battery positive voltage)? 

• YES:  Go to  Step 9.
• NO:  Go to Step 7.
  Fig 3: Measuring Voltage Between Heated Seat Relay Connector B-316 Terminal 1 And Ground

  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Q: Is Junction block connector B-302 in good condition? 

• YES:  Go to Step 8.
• NO:  Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION . Verify that the power window works normally.

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

Q: Is the wiring harness between heated seat connector B-316 (terminal 1) and junction block connector B-302 (terminal 6) in good condition? 

• YES:  No action is necessary and testing is complete.
• 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. Check that the power window works normally.

1. Disconnect heated seat relay connector B-316 and measure the voltage available at the wiring harness side of the connector.
2. Turn the electric motor switch to the "ON" position.
3. Measure the voltage between terminal 4 and ground.
   • The voltage should measure approximately 12 volts (battery positive voltage).

Q: Is the measured voltage approximately 12 volts (battery positive voltage)? 

• YES:  Go to  Step 12.
• NO:  Go to Step 10.
  Fig 4: Measuring Voltage Between Heated Seat Relay Connector B-316 Terminal 4 And Ground

  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Q: Is Junction block connector B-310 in good condition? 

• YES:  Go to Step 11.
• NO:  Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION . Verify that the power window works normally.

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

Q: Is the wiring harness between heated seat connector B-316 (terminal 4) and junction block connector B-310 (terminal 1) in good condition? 

• YES:  No action is necessary and testing is complete.
• 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. Check that the power window works normally.

Q: Is Junction block connector B-303 in good condition? 

• YES:  Go to Step 13.
• NO:  Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION . Verify that the power window works normally.

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

Q: Is the wiring harness between heated seat connector B-316 (terminal 3) and junction block connector B-303 (terminal 7) in good condition? 

• YES:  Go to Step 14
• 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. Check that the power window works normally.

• Refer to check the heated seat switches CONTINUITY TEST OF HEATED SEAT SWITCH  .
• Refer to check the heated seats INSPECTION < VEHICLES WITH HEATED SEAT >  .
• harness wires and connectors.

Q: Is the check result normal? 

• YES:  Intermittent malfunction (Refer to HOW TO USE TROUBLESHOOTING/INSPECTION SERVICE POINTS - HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).
• NO:  Replace the heated seat relay, the heated seat switches, the heated seats.