DTC 48: Cal FR Brake Fluid Pressure Sensor Circuit Open/Short

Turn the ignition switch ON (II).
Clear the DTCs with the HDS.
Watch the adaptive cruise control (ACC) indicator.
Does the ACC indicator stay off?

YES - Intermittent failure, the system is OK at this time. Check for loose or poor connections.

NO - Go to step 4.
Check for DTCs with the HDS.
Is DTC 48 indicated?

YES - Go to step 5.

NO - Troubleshoot the indicated DTC(s). If there are no DTCs, the system is OK at this time.
Check the right front brake fluid pressure voltage (RF BRAKE P) with the HDS.
Is there about 0.5 V?

YES - Go to step 6.

NO - Go to step 13.
Test the brake booster (see BRAKE BOOSTER TEST ).
Press the brake pedal with about 314 N (32 kgf, 70.6 lbf) pressure.
Check the right front brake fluid pressure voltage (RF BRAKE P) with the HDS.
Is there about 2.5 V?

YES - The right front brake fluid pressure signal is OK, check for loose or poor connections. If OK, replace the ACC unit (see DISTANCE SWITCH TEST ).

NO - Go to step 9.
Turn the ignition switch OFF.
Disconnect the 20P connector from the ACC unit.
Check for continuity between the ACC unit 20P connector No. 5 terminal and body ground.

Fig 1: Checking For Continuity Between ACC Unit 20P Connector No. 5 Terminal And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Repair a short to ground in the wire between the ACC unit and the right front pressure sensor.

NO - Go to step 12.
Disconnect the 3P connector from the right front pressure sensor.
Connect the right front pressure sensor 3P connector No. 2 terminal to body ground with a jumper wire.

Fig 2: Connecting Right Front Pressure Sensor 3P Connector No. 2 Terminal To Body Ground With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between the ACC unit 20P connector No. 5 terminal and body ground.

Fig 3: Checking For Continuity Between ACC Unit 20P Connector No. 5 Terminal And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Go to step 15.

NO - Repair an open in the wire between the ACC unit and the right front pressure sensor.
Remove the jumper wire from the right front pressure sensor.
Reconnect all connectors.
Turn the ignition switch ON (II).
Measure the voltage between the ACC unit 20P connector No. 3 and No. 5 terminals.

Fig 4: Measuring Voltage Between ACC Unit 20P Connector No. 3 And No. 5 Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there about 5V?

YES - Go to step 19.

NO - Check for loose or poor connections. If OK, replace the ACC unit (see DISTANCE SWITCH TEST ).
Turn the ignition switch OFF.
Disconnect the 20P connector from the ACC unit.
Check for continuity between the ACC unit 20P connector No. 6 terminal and body ground.

Fig 5: Checking For Continuity Between ACC Unit 20P Connector No. 6 Terminal And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Repair a short to ground in the wire between the ACC unit and the right front pressure sensor.

NO - Go to step 22.
Disconnect the 3P connector from the right front pressure sensor.
Connect the right front pressure sensor 3P connector No. 3 terminal to body ground with a jumper wire.

Fig 6: Connecting Right Front Pressure Sensor 3P Connector No. 3 Terminal To Body Ground With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between the ACC unit 20P connector No. 6 terminal and body ground.

Fig 7: Checking For Continuity Between ACC Unit 20P Connector No. 6 Terminal And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Go to step 25.

NO - Repair an open in the wire between the ACC unit and the right front pressure sensor.
Check for continuity between the ACC unit 20P connector No. 5 terminal and body ground.

Fig 8: Checking For Continuity Between ACC Unit 20P Connector No. 5 Terminal And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Repair a short in the wire between the PRESS FR line and VCC line.

NO - Go to step 26.
Check for continuity between the ACC unit 20P connector No. 3 terminal and body ground.

Fig 9: Checking For Continuity Between ACC Unit 20P Connector No. 3 Terminal And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Go to step 27.

NO - Repair an open in the wire between the ACC unit and the right front pressure sensor.
Remove the jumper wire from the right front pressure sensor.
Reconnect all connectors.
Turn the ignition switch ON (II).
Measure the voltage between the ACC unit 20P connector No. 3 and No. 6 terminals.

Fig 10: Measuring Voltage Between ACC Unit 20P Connector No. 3 And No. 6 Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there about 0.5V?

YES - Go to step 31.

NO - Replace the right front pressure sensor.
Clear the DTCs with the HDS.
Watch the ACC indicator.
Does the ACC indicator stay off?

YES - Intermittent failure, the system is OK at this time. Check for loose or poor connections.

NO - Go to step 33.
Check for DTCs with the HDS.
Is DTC 48 indicated?

YES - Check for loose or poor connections. If OK, replace the ACC unit (see DISTANCE SWITCH TEST ).

NO - Troubleshoot the indicated DTC(s). If there are no DTCs, the system is OK at this time.