DTC 23-1, 23-2, 24-1, 24-2: Rear Wheel Speed Sensors

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

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Test-drive the vehicle at speeds over 25 mph (40 km/h), while keeping the engine speed below 2, 500 rpm for at least 30 seconds.
NOTE: Be careful not to overheat the rear differential clutch system.
Check for DTCs with the HDS.
Is DTCs 23-1, 23-2, 24-1, and/or 24-2 indicated?

YES -Go to step 5.

NO -Intermittent failure, the system is OK at this time. ■
Check for DTCs in the VSA system with the HDS.
Are there any VSA DTCs indicated?

YES -go to the indicated DTCs troubleshooting. ■

NO -Go to step 6.
Turn the ignition switch to LOCK (0).
Raise and support the vehicle (see LIFT AND SUPPORT POINTS ).
Spin the rear wheels by hand, and check for rear brake drag.
Are the rear brakes dragging?

YES -Inspect and repair the cause for rear brake drag (see RAPID BRAKE PAD WEAR (BRAKE DRAG), VEHICLE VIBRATION (AFTER A LONG DRIVE), OR HIGH, HARD BRAKE PEDAL ).

NO -Go to step 9.
Turn the ignition switch to ON (II).

Measure the voltage between body ground and the appropriate VTM-4 control unit connector terminal (see table) while rotating the appropriate wheel (1 rotation/second).

VOLTAGE REFERENCE

DTC	Appropriate Terminal
23-1, 23-2 (Left-rear)	A5
24-1, 24-2 (Right-rear)	A3

Fig 1: Measuring Voltage Between VTM-4 Control Unit Connector Terminals A3 And A5 To Body Ground

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there about 2.0 V to 3.0 V?

YES -Go to step 18

NO -Go to step 11.

Turn the ignition switch to LOCK (0).
Disconnect VTM-4 control unit connector A (22P) and the VSA modulator-control unit 46P connector.
Check for continuity between VTM-4 control unit connector terminals A3 and A5 to body ground respectively.

Fig 2: Checking Continuity Between VTM-4 Control Unit Connector Terminals A3 And A5 To Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair short to ground in the wire between VTM-4 control unit (A3 and/or A5) and the VSA modulator-control unit. ■

NO -Go to step 14.

Connect body ground and the appropriate VTM-4 control unit connector terminal with jumper wires (see table).

VOLTAGE REFERENCE

DTC	Appropriate Terminal
23-1, 23-2 (Left-rear)	A5
24-1, 24-2 (Right-rear)	A3

Fig 3: Connecting VTM-4 Control Unit Connector Terminals A3 And A5 To Body Ground

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Check for continuity between body ground and the appropriate VSA modulator-control unit 46P connector terminal (see table).

CONTINUITY REFERENCE

DTC	Appropriate Terminal
DTC	Appropriate Terminal
23-1, 23-2 (Left-rear)	24
24-1, 24-2 (Right-rear)	3

Fig 4: Checking Continuity Between VSA Modulator-Control Unit 46P Connector Terminals And Body Ground

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 16.

NO -Repair open in the wire between VTM-4 control unit (A3 and/or A5) and the VSA modulator-control unit.

Reconnect all connectors.
Check for poor connection or loose terminals at the VTM-4 control unit and the VSA modulator-control unit connectors. If the connections are OK, substitute a known-good VTM-4 control unit (see VTM-4 CONTROL UNIT REPLACEMENT ) and recheck. If the symptom/indication goes away with the known-good VTM-4 control unit, replace the original VTM-4 control unit (see VTM-4 CONTROL UNIT REPLACEMENT ), then Go to step 18.
Test-drive the vehicle at speeds over 25 mph (40 km/h), while keeping the engine speed below 2, 500 rpm for at least 30 seconds.
NOTE: Be careful not to overheat the rear differential clutch system.
Check for DTCs with the HDS.
Is DTCs 23-1, 23-2, 24-1, and/or 24-2 indicated?

YES -Replace the VSA modulator-control unit (see VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ). ■

NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.