MIC-In Circuit Inspection

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

■ Check for open in harness

Ignition "OFF"
Disconnect Head Unit and TMU main harness connector.
Measure resistance between M-CAN (High), (Low) terminal of Head Unit harness connector and M-CAN (High), (Low) terminal of TMU harness connector.
Specification: below 1

Fig 1: Measuring Resistance Between TMU & Head Unit Harness Connectors M-CAN Low Terminal And M-CAN High Terminal
Courtesy of HYUNDAI MOTOR AMERICA
Is the measured resistance within specifications?
YES
- Go to next procedure.
NO
- Check for open in harness & Repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.

■ Check short to ground in harness

Ignition "OFF".
Disconnect Head Unit and TMU main harness connector.
Measure resistance between M-CAN (High), (Low) terminal of TMU harness connector and chassis ground.
Specification: Infinity

Fig 2: Measuring Resistance Between TMU Harness Connector M CAN Low & High Terminals And Chassis Ground
Courtesy of HYUNDAI MOTOR AMERICA
Is the measured resistance within specifications?
YES
- Go to next procedure.
NO
- Check for open or contact resistance in ground harness.
- Repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.

■ Check short to B+ in harness

Ignition "OFF".
Disconnect Head Unit and TMU main harness connector.
Ignition "ON".
Measure Voltage between M-CAN (High), (Low) terminal of TMU harness connector and chassis ground.
Specification: 0V.

Fig 3: Measuring Voltage Between TMU Harness Connector M CAN Low & High Terminals And Chassis Ground
Courtesy of HYUNDAI MOTOR AMERICA
Is the measured Voltage within specifications?
YES
- Check Head Unit & TMU for looseness, poor connection, ending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
- Substitute with a known-good Head Unit and check for proper operation.
  If the problem is corrected, replace Head Unit and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
- Substitute with a known-good TMU and check for proper operation.
  If the problem is corrected, replace TMU and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
NO
- Check for open or contact resistance in ground harness.
  Repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.