Inspection Procedure 2

INSPECTION PROCEDURE 2: No Communication is Possible Between the scan tool and AWD-ECU.

DATA LINK CONNECTOR CIRCUIT
Refer to Inspection Procedure 1: No Communication Possible Between Scan Tool and All Systems. Inspection Procedure 1

CIRCUIT OPERATION
The scan tool will be able to communicate with the AWD-ECU by connecting the data link connector.

COMMENT
The DTC output circuit, AWD-ECU power supply circuit, ground circuit or AWD-ECU may be faulty.

TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CONDITION:)
^ Damaged harness and connector
^ Malfunction of the AWD-ECU

DIAGNOSIS
STEP 1. Measure the DTC output circuit for resistance between data link connector C-14 and AWD-ECU connector C-138.








1) Disconnect connector C-138 and measure at the harness side.
2) Measure the resistance between data link connector C-14 terminal 1 and AWD-ECU connector C-138 terminal 46.
^ The resistance should measure less than 2 ohms.

3) Measure the resistance between data link connector C-14 terminal 7 and AWD-ECU connector C-138 terminal 35.
^ The resistance should measure less than 2 ohms.
Q: Is the measured resistance less than 2 ohms?
YES: Go to Step 4.
NO: Go to Step 2.

STEP 2. Check data link connector C-14, joint connector (4) C-23, joint connector (2)C-101, joint connector (6) C-105, intermediate connector C-124 and AWD-ECU connector C-138 for loose, corroded or damaged terminals, or terminals pushed back in the connector.




















Q: Are the connectors and terminals in good condition?
YES: Go to Step 3.
NO: Repair or replace the damaged components.

STEP 3. Check the harness for open circuit or short circuit to ground between data link connector C-14 (terminal 1 and 7) and AWD-ECU connector C-138 (terminal 46 and 35).








Q: Is the harness wire in good condition?
YES: It can be assumed that this malfunction is intermittent.
NO: Repair or replace the harness wire.

STEP 4. Measure the power supply voltage at AWD-ECU connector C-139 by backprobing.








1) Turn the ignition switch to the ON position.
2) Measure the voltage between AWD-ECU connector C-139 terminal 13 and ground by backprobing.
^ The voltage should measure battery positive voltage.

3) Turn the ignition switch to the Lock (OFF) position.
Q: Is the measured voltage battery positive voltage?
YES: Go to Step 7.
NO: Go to Step 5.

STEP 5. Check intermediate connector C-124, AWD-ECU connector C-139, junction block connector C-210 and C-211 for loose, corroded or damaged terminals, or terminals pushed back in the connector.











Q: Are the connectors and terminals in good condition?
YES: Go to Step 6.
NO: Repair or replace the damaged components.

STEP 6. Check the harness for open circuit or short circuit between AWD-ECU connector C-139 terminal 13 and ignition switch.





Q: Is the harness wire in good condition?
YES: It can be assumed that this malfunction is intermittent.
NO: Repair or replace the harness wire.

STEP 7. Measure the ground circuit for resistance at AWD-ECU connectors C-138 and C-139 by backprobing.








1) Measure the resistance between AWD-ECU connector C-138 terminals 42, 50 and ground by backprobing.
^ The resistance should measure less than 2 ohms.








2) Measure the resistance between AWD-ECU connector C-139 terminal 26 and ground by backprobing.
^ The resistance should measure less than 2 ohms.
Q: Is the measured resistance less than 2 ohms?
YES: Go to Step 10.
NO: Go to Step 8.

STEP 8. Check AWD-ECU connector C-138 and C-139 for loose, corroded or damaged terminals, or terminals pushed back in the connector.








Q: Are the connectors and terminals in good condition?
YES: Go to Step 9.
NO: Repair or replace the damaged components.

STEP 9. Check the harness for open circuit between AWD-ECU connector C-138 terminals 42 and 50, C-139 terminal 26 and ground.








Q: Is the harness wire in good condition?
YES: It can be assumed that this malfunction is intermittent.
NO: Repair or replace the harness wire.

STEP 10. Check AWD-ECU connector C-138 and C-139 for loose, corroded or damaged terminals, or terminals pushed back in the connector.








Q: Are the connectors and terminals in good condition?
YES: Repair the AWD-ECU.
NO: Repair or replace the harness wire.