DTC B1840: Tilt Motor Pulse Error

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: 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 to ON (II).
Operate the tilt switch in each direction for at least 6 seconds.
Check for DTCs with the HDS.
Is DTC B1840 indicated?

YES -Go to step 5.

NO -Intermittent failure, the system is OK at this time. Check for loose or poor connections.
Check for DTCs with the HDS.
Is DTC B1841 also indicated?

YES -Go to step 17.

NO -Go to step 6.
Clear the DTCs with the HDS.
Turn the ignition switch to LOCK (0) and then back to ON (II).
Operate the tilt switch for 2 seconds, and check the tilt motor operation.
Does the tilt motor run smoothly?

YES -Go to step 9.

NO -Go to step 26.
Turn the ignition switch to LOCK (0).
Disconnect power tilt/telescopic steering control unit connector A (16P).
Disconnect the power tilt motor/position sensor 8P connector.
Check for continuity between power tilt/telescopic steering control unit connector A (16P) terminals No. 4, No. 12, and No. 16 and power tilt motor/position sensor 8P connector terminals No. 6, No. 7, and No. 8 respectively.

Fig 1: Checking Continuity Between Connector (16P) Terminals And 8P Connector Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 13.

NO -Repair an open in the wire.
Check for continuity between body ground and power tilt/telescopic steering control unit connector A (16P) terminals No. 4 and No. 12 individually.

Fig 2: Checking Continuity Between Body Ground And Connector (16P) Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short to ground in the wire.

NO -Go to step 14.
Reconnect power tilt/telescopic steering control unit connector A (16P).
Turn the ignition switch to ON (II).
Measure the voltage between power tilt motor/position sensor 8P connector terminals No. 6 and No. 8 and between terminals No. 7 and No. 8.

Fig 3: Measuring Voltage Between 8P Connector Terminals No. 6 And No. 8 And Between Terminals No. 7 And No. 8
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there about 5 V?

YES -Faulty power tilt motor/position sensor, replace the tilt motor assembly.

NO -If there is no voltage, replace the power tilt/telescopic steering control unit. If there is battery voltage, repair a short in the wire.
Turn the ignition switch to LOCK (0).
Disconnect power tilt/telescopic steering control unit connector A (16P).
Disconnect the power tilt motor/position sensor 8P connector.
Check for continuity between power tilt/telescopic steering control unit connector A (16P) terminals No. 2 and No. 16 and power tilt motor/position sensor 8P connector terminals No. 5 and No. 8 respectively.

Fig 4: Checking Continuity Between Connector (16P) Terminals And 8P Connector Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 21.

NO -Repair an open in the wire.
Disconnect the power telescopic motor/position sensor 6P connector.
Check for continuity between power tilt motor/position sensor 8P connector terminal No. 5 and body ground.

Fig 5: Checking Continuity Between 8P Connector Terminal No. 5 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short to ground in the wire.

NO -Go to step 23.
Reconnect power tilt/telescopic steering control unit connector A (16P).
Turn the ignition switch to ON (II).
Measure the voltage between power tilt/telescopic steering control unit connector A (16P) terminals No. 2 and No. 16.

Fig 6: Measuring Voltage Between Connector (16P) Terminals No. 2 And No. 16.
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage when the tilt switch is operated?

YES -Faulty power tilt motor/position sensor, replace the tilt motor assembly.

NO -Replace the power tilt/telescopic steering control unit.
Turn the ignition switch to LOCK (0).
Disconnect power tilt/telescopic steering control unit connector B (8P).
Disconnect the power tilt motor/position sensor 8P connector.
Check for continuity between power tilt/telescopic steering control unit connector B (8P) terminals No. 7 and No. 8 and power tilt motor/position sensor 8P connector terminals No. 2 and No. 3 respectively.

Fig 7: Checking Continuity Between Connector B (8P) Terminals And 8P Connector Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 30.

NO -Repair an open in the wire.
Check for continuity between body ground and power tilt motor/position sensor 8P connector terminals No. 2 and No. 3 individually.

Fig 8: Checking Continuity Between Body Ground And 8P Connector Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short to ground in the wire.

NO -Go to step 31.
Do the tilt motor test, (see POWER TILT/TELESCOPIC STEERING MOTOR TEST )
Is the motor OK?

YES -Replace the power tilt/telescopic steering control unit.

NO -Replace the power tilt motor/position sensor.