DTC 41-4: F-CAN Malfunction (Lost Communication with A/T Control Unit)

WARNING: This page is about a different car, the 2013 Acura MDX, 2012 Acura MDX, 2011 Acura MDX, and 2010 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.

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

Turn the ignition switch to ON (II).
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 3.
Clear the DTC with the HDS.
Start the engine.
Check for DTCs with the HDS.
Is DTC 41-4 indicated?

YES -Go to step 6.

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

Fig 1: Checking Continuity Between PCM Connector Terminals A48, A49 And SH-AWD Control Unit Connector Terminals A10, A20
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 PCM.