DTC 41-1: F-CAN Malfunction (Lost Communication with Engine Control Module (ECM)/Powertrain Control Module (PCM))

NOTE: Before you troubleshoot, review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
Clear the DTC with the HDS.
Start the engine.
Check for DTCs in the PGM-FI system with the HDS.
Are there any PGM-FI system DTCs indicated?

YES - Go to the indicated DTC'S TROUBLESHOOTING .

NO - Go to step 5.
Check for DTCs with the HDS.
Is DTC 41-1 indicated?

YES - Go to step 6.

NO - Intermittent failure, the system is OK at this time. Check for an intermittent open between SH-AWD control unit connector terminals A10 and A20 and ECM/PCM connector terminals A48 and A49.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
Jump the SCS line with the HDS.
NOTE: This step must be done to prevent ECM/PCM damage.
Disconnect ECM/PCM connector A (49P).
Disconnect SH-AWD control unit connector A (20P).
Check for continuity between ECM/PCM connector terminals A48, A49 and SH-AWD control unit connector terminals A10, A20 respectively.

Fig 1: Checking Continuity Between ECM/PCM Connector Terminals And SH-AWD Control Unit Connector Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Update the SH-AWD control unit if it does not have the latest software (see SH-AWD® CONTROL UNIT UPDATE ), or substitute a known-good SH-AWD control unit (see SH-AWD® CONTROL UNIT REPLACEMENT ), and recheck. If the symptom/indication goes away with the updated SH-AWD control unit, troubleshooting is complete. If the symptom/indication goes away with a known-good SH-AWD control unit, replace the original SH-AWD control unit (see SH-AWD® CONTROL UNIT REPLACEMENT ).

NO - Repair an open in the wires between the SH-AWD control unit and the ECM/PCM.