DTC U0100-00 (41-01): F-CAN Malfunction (Lost Communication With Powertrain Control Module (PCM)), U0101-00 (41-04): F-CAN Malfunction (Lost Communication With A/T Control System), U0122-00 (41-02): F-CAN Malfunction (Lost Communication With VSA Modulator-Control Unit), U0126-00 (41-06): F-CAN Malfunction (Lost Communication With Steering Angle Sensor)

NOTE: 

• Troubleshoot any PGM-FI DTCs first.
• Before you troubleshoot, Refer to: HOW TO TROUBLESHOOT THE REAL TIME AWD SYSTEM (AWD) .

DTC (Real Time AWD)

1. Problem verification (DTC check)

   - 1. Turn the vehicle to the ON mode.

   - 2. Clear the DTC with the HDS.

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

   - 4. Start the engine.

   - 5. Check for DTCs with the HDS.

   DTC Description	DTC	Freeze Frame
   U0100-00: F-CAN Malfunction (Lost Communication with Powertrain Control Module (PCM))
   U0101-00: F-CAN Malfunction (Lost Communication with A/T Control System)
   U0122-00: F-CAN Malfunction (Lost Communication with VSA Modulator-Control Unit)
   U0126-00: F-CAN Malfunction (Lost Communication with Steering Angle Sensor)

   Is DTC U0100-00, U0101-00, U0122-00, or U0126-00 indicated?

   DTC U0100-00 or U0101-00 is indicated

   The failure is duplicated. Go to step 2.

   DTC U0122-00 is indicate

   The failure is duplicated. Go to step 3.

   DTC U0126-00 is indicated

   The failure is duplicated. Go to step 4.

   DTC is not indicated

   Intermittent failure, the system is OK at this time. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the Freeze data/on-board snapshot.

2. Open wire check (F-CAN_H, F-CAN_L lines) 1

   - 1. Turn the vehicle to the OFF (LOCK) mode, and wait 2 minutes.

   - 2. Jump the SCS line with the HDS, and wait more than 1 minute.

   - 3. Disconnect the following connectors.

   Real time AWD control unit 24P connector

   PCM connector A (51P)

   - 4. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Real time AWD control unit 24P connector: disconnected
   	PCM connector A (51P): disconnected
   Test point 1	Courtesy of HONDA, U.S.A., INC.
   Test point 2	Courtesy of HONDA, U.S.A., INC.

   Test point 1	Courtesy of HONDA, U.S.A., INC.
   Test point 2	Courtesy of HONDA, U.S.A., INC.

   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 PCM.

3. Open wire check (F-CAN_H, F-CAN_L lines) 2

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

   - 2. Disconnect the following connectors.

   Real time AWD control unit 24P connector

   VSA modulator-control unit 38P connector

   - 3. Check for continuity between test points 1 and 2 individually.

   Test condition	Vehicle OFF (LOCK) mode
   	Real time AWD control unit 24P connector: disconnected
   	VSA modulator-control unit 38P connector: disconnected
   Test point 1	Courtesy of HONDA, U.S.A., INC.
   Test point 2	Courtesy of AMERICAN HONDA MOTOR CO., INC.

   Test point 1	Courtesy of HONDA, U.S.A., INC.
   Test point 2	Courtesy of AMERICAN HONDA MOTOR CO., INC.

   Is there continuity?

   YES 

   Refer to: VSA MODULATOR-CONTROL UNIT UPDATE , and recheck. If the symptom/indication goes away with the updated VSA modulator-control unit, troubleshooting is complete. If the symptom/indication does not goes away with the updated the VSA modulator-control unit, VSA MODULATOR-CONTROL UNIT REMOVAL & INSTALLATION .

   NO 

   Repair an open in the F-CAN_H and/or F-CAN_L wires between the real time AWD control unit and the VSA modulator-control unit.

4. Open wire check (F-CAN_H, F-CAN_L lines) 3

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

   - 2. Disconnect the following connectors.

   Real time AWD control unit 24P connector

   Steering angle sensor 4P connector

   - 3. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Real time AWD control unit 24P connector: disconnected
   	Steering angle sensor 4P connector
   Test point 1	Courtesy of HONDA, U.S.A., INC.
   Test point 2	Steering angle sensor 4P connector No. 2

   Test point 1	Courtesy of HONDA, U.S.A., INC.
   Test point 2	Steering angle sensor 4P connector No. 3

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

   Is there continuity?

   YES 

   STEERING ANGLE SENSOR NEUTRAL POSITION CLEAR .

   NO 

   Repair an open in the F-CAN_H and/or F-CAN_L wires between the real time AWD control unit and the steering angle sensor.