CAN Communication Line Check

■ CAN Communication Circuit Inspection (SAS ↔ 4WD ECU) 

1. Ignition "OFF"
2. Disconnect 4WD ECU connector and PCM connector.
3. Measure the resistance between CAN-HIGH terminal of 4WD ECU harness connector and CAN-HIGH terminal of PCM harness connector.
4. Measure the resistance between CAN-LOW terminal of 4WD ECU harness connector and CAN-LOW terminal of PCM harness connector.

   Specification:  below 1Ω

5. Is the measured resistance within specification?

   YES 

   • Substitute with a known - good PCM and check for proper operation. If the problem is corrected, replace PCM and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

   NO 

   • Check for open/short in harness.
   • Repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.

■ Check Short to Ground in CAN Communication Line 

1. IG Key "OFF".
2. Measure resistance between CAN high terminal (# 3) of diagnostic connector and chassis ground.
3. Measure resistance between CAN low terminal (# 11) of diagnostic connector and chassis ground.

   Specification:  ∞ Ω

4. Is the measured value within specification?

   YES 

   • Check PCM, 4WD ECU, TCM and SAS connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.

   NO 

   • Check short to battery in communication line. And then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.
   • Check short to ground in communication line. And then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.