CAN Communication Line Inspection

Check for Open in Harness
1. Ignition "OFF".
2. Disconnect Head Unit and TMU (MTS) Module main harness connector.
3. Measure resistance between M-CAN (High), (Low) terminal of Head Unit harness connector and M-CAN (High), (Low) terminal of TMU (MTS) Module harness connector.
  Specification: Below 1
4. Is the measured resistance within specification?
  YES
  
  Continue 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
1. Ignition "OFF".
2. Disconnect Head Unit and TMU (MTS) Module main harness connector.
3. Measure resistance between M-CAN (High), (Low) terminal of TMU (MTS) Module harness connector and chassis ground.
  Specification: Infinity
4. Is the measured value within specification?
  YES
  
  Continue 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 Battery in CAN Communication Line
1. Ignition "OFF".
2. Disconnect Head Unit and TMU (MTS) Module main harness connector.
3. Ignition "ON".
4. Measure Voltage between M-CAN (High), (Low) terminal of TMU (MTS) Module harness connector and chassis ground.
  Specification: Approx. 0V
5. Is the measured value within specification?
  YES
  
  Check Head Unit & TMU (MTS) Module 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 (MTS) Module and check for proper operation. If the problem is corrected, replace TMU (MTS) Module 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.