AWD System Symptom Troubleshooting - HDS does not communicate (AWD) (2016 2017 2018)

HDS does not communicate 

1. 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 

   Go to the DLC circuit troubleshooting .

2. AWD with intelligent control system communication check

   -1. Check the Main Menu of the AWD WITH INTELLIGENT CONTROL with the HDS.

   Does the HDS show the Main Menu of the AWD WITH INTELLIGENT CONTROL?

   YES 

   The AWD with intelligent control system communication is OK. Intermittent failure, the system is OK at this time.

   NO 

   Go to step 3.

3. Fuse check

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Check the following fuse.

   Fuse	No. C39 (10 A)
   Location	Under-hood 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. C39 (10 A) fuse circuit.

4. 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.

   Is the AWD relay OK?

   NO 

   Repair an open in the F-CAN_H and/or F-CAN_L wires.

   YES 

   Go to step 5.

5. 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 AWD WITH INTELLIGENT CONTROL with the HDS.

   Does the HDS show the Main Menu of the AWD WITH INTELLIGENT CONTROL?

   YES 

   Replace the rear differential fluid pressure sensor .

   NO 

   The rear differential fluid pressure sensor is OK. Go to step 6.

6. Open wire check (IG1 OPTION line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the following connector.

   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
   	AWD control unit 24P connector: disconnected
   Test point 1	AWD control unit 24P connector No. 12
   Test point 2	Body ground

   Is there battery voltage?

   YES 

   The IG1 OPTION wire is OK. Go to step 7.

   NO 

   Repair an open in the IG1 OPTION wire between the AWD control unit and the No. C39 (30 A) fuse in the under-hood fuse/relay box..

7. 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
   	AWD control unit 24P connector: disconnected
   Test point 1	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 AWD control unit and ground (G505).

8. Shorted wire check (SVCC 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
   	AWD control unit 24P connector: disconnected
   Test point 1	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 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)

   -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
   	AWD control unit 24P connector: disconnected
   Test point 1	AWD control unit 24P connector No. 14
   Test point 2	DLC (16P) No. 6

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

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   Update the AWD control unit if it does not have the latest software , or substitute a known-good AWD control unit , and recheck. If the symptom/indication goes away with the updated AWD control unit, troubleshooting is complete. If the symptom/indication goes away with a known-good AWD control unit, replace the original AWD control unit .

   NO 

   Repair an open in the F-CAN_H and/or F-CAN_L wires between the AWD control unit and the DLC.