DTC B2178: Front Passenger's Power Window Motor Pulse B Error

WARNING: This page is about a different car, the 2009 Acura MDX, 2008 Acura MDX, and 2007 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).

Clear the DTCs with the HDS.
Turn the ignition switch to LOCK (0), and then back ON (II).
Open and close the front passenger's power window by using the front passenger's power window switch manually.
Check for DTCs with the HDS.
Is DTC B2178 indicated?

YES - Go to step 5.

NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections.
Open and close the front passenger's power window by using the power window master switch manually.
Does the window motor operate?

YES - Go to step 6.

NO - Test the front passenger's power window motor (see FRONT PASSENGER'S POWER WINDOW MOTOR TEST ).
Select the POWER WINDOWS from the BODY ELECTRICAL system select menu and enter the DATA LIST.
Check the DETECT/NONE information of the Front passenger's window motor B-phase pulse signal in the DATA LIST.
Does the information indicator display DETECT while the window is moving, and display NONE when the window is stopped?

YES - Replace the front passenger's MPCS unit.

NO - Go to step 8.
Check for DTCs with the HDS.
Is DTC B2177 also indicated?

YES - Go to step 15.

NO - Go to step 9.
Turn the ignition switch to LOCK (0).
Disconnect front passenger's MPCS unit connector B(14P).
Disconnect the 6P connector from the passenger's power window motor.
Check for continuity between front passenger's MPCS unit connector B (14P) No. 4 terminal and front passenger's power window motor 6P connector No. 2 terminal.

Fig 1: Identifying Continuity Between Front Passenger's MPCS Unit B (14P) Connector Terminal 4
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Go to step 13.

NO - Repair open in the wire.
Check for continuity between front passenger's power window motor 6P connector No. 2 terminal and body ground.

Fig 2: Identifying Continuity Between Front Passenger's Power Window Motor Connector Terminal 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Repair short in the wire.

NO - Go to step 14.
Test the front passenger's power window motor (see FRONT PASSENGER'S POWER WINDOW MOTOR TEST ).
Is the motor OK?

YES - Replace the front passenger's MPCS unit.

NO - Replace the front passenger's power window motor.
Check for continuity between the front passenger's MPCS unit connector B (14P) No. 3 and No. 6 terminals and the front passenger's power window motor 6P connector No. 5 and No. 6 terminals respectively.

Fig 3: Identifying Continuity Between Front Passenger's MPCS Unit B (14P) Connector Terminals 3 And 6
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Go to step 16.

NO - Repair open in the wire.
Check for continuity between the front passenger's power window motor 6P connector No. 6 terminal and body ground.

Fig 4: Identifying Continuity Between Front Passenger's Power Window Motor Connector Terminal 6 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Repair short to ground in the wire.

NO - Replace the front passenger's power window motor.