Real Time AWD System Symptom Troubleshooting - HDS does not communicate
HDS does not communicate
1.
HDS communication check:

HDS communication check
?1.
Turn the vehicle to the ON mode.

?2.
Check that the HDS communicates with the vehicle.

Does the HDS communicate with the vehicle?

     
YES
     
     
     
The HDS communication is OK. Go to step 2.
     
NO
     
     
     
2.
Real time AWD system communication check:

Real time AWD system communication check
?1.
Check the Main Menu of the REAL TIME AWD with the HDS.

Does the HDS show the Main Menu of the REAL TIME AWD?

     
YES
     
     
     
The real time AWD system communication is OK. Intermittent failure, the system is OK at this time.?
     
NO
     
     
     
Go to step 3.
3.
Fuse check:

Fuse check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Check the following fuse.
Fuse
No. B6 (7.5 A)
Location
Under-dash fuse/relay box

Is the fuse OK?

     
YES
     
     
     
The fuse is OK. Reinstall the fuse, then go to step 4.
     
NO
     
     
     
Repair a short to ground in the No. B6 (7.5 A) fuse circuit.?
4.
Rear differential pump motor operation check:

Rear differential pump motor operation check
?1.
Turn the vehicle to the ON mode.

?2.
Check the operation sound of the rear differential pump motor on the rear differential with a stethoscope or a flat-tipped screwdriver (at the rear differential pump motor) when the engine started.
NOTE: The rear differential pump motor operates within several seconds after the engine is started.

Rear differential pump motor operation sound heard?

     
YES
     
     
     
Go to step 5.
     
NO
     
     
     
Repair an open in the F-CAN_H and/or F-CAN_L wires.?
5.
Rear differential fluid pressure sensor check:

Rear differential fluid pressure sensor check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Rear differential fluid pressure sensor 3P connector

?3.
Turn the vehicle to the ON mode.

?4.
Check the Main Menu of the REAL TIME AWD with the HDS.

Does the HDS show the Main Menu of the REAL TIME AWD?

     
YES
     
     
     
     
NO
     
     
     
The rear differential fluid pressure sensor is OK. Go to step 6.
6.
Open wire check (IG1 P/W line):

Open wire check (IG1 P/W line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Real time AWD control unit 24P connector

?3.
Start the engine.

?4.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode (idling)
 
Rear differential fluid pressure sensor 3P connector: disconnected
 
Real time AWD control unit 24P connector: disconnected
Test point 1
Real time AWD control unit 24P connector No. 12
Test point 2
Body ground

Is there battery voltage?

     
YES
     
     
     
The wire is OK. Go to step 7.
     
NO
     
     
     
Repair an open in the wire between the real time AWD control unit and the No. B6 (7.5 A) fuse in the under-dash fuse/relay box.?
7.
Open wire check (GND line):

Open wire check (GND line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Rear differential fluid pressure sensor 3P connector: disconnected
 
Real time AWD control unit 24P connector: disconnected
Test point 1
Real time AWD control unit 24P connector No. 8
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
The GND wire is OK. Go to step 8.
     
NO
     
     
     
Repair an open in the GND wire between the real time AWD control unit and ground (G603).?
8.
Shorted wire check (SVCC line):

Shorted wire check (SVCC line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Rear differential fluid pressure sensor 3P connector: disconnected
 
Real time AWD control unit 24P connector: disconnected
Test point 1
Real time AWD control unit 24P connector No. 20
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short to ground in the SVCC wire between the real time AWD control unit and the rear differential fluid pressure sensor.?
     
NO
     
     
     
The SVCC wire is OK. Go to step 9.
9.
Open wire check (F-CAN_H, F-CAN_L lines):

Open wire check (F-CAN_H, F-CAN_L lines)
?1.
Check for continuity between test points 1 and 2 individually.
Test condition
Vehicle OFF (LOCK) mode
 
Rear differential fluid pressure sensor 3P connector: disconnected
 
Real time AWD control unit 24P connector: disconnected
Test point 1
Real time AWD control unit 24P connector No. 14
Test point 2
DLC (16P) No. 6

Test point 1
Real time AWD control unit 24P connector No. 24
Test point 2
DLC (16P) No. 14


Is there continuity?

     
YES
     
     
     
Update the real time AWD control unit if it does not have the latest software, or substitute a known-good real time AWD control unit, and recheck. If the symptom/indication goes away with the updated real time AWD control unit, troubleshooting is complete. If the symptom/indication goes away with a known-good real time AWD control unit, replace the original real time AWD control unit.?
     
NO
     
     
     
Repair an open in the F-CAN_H and/or F-CAN_L wires between the real time AWD control unit and the DLC.?