DTC 44: Cal FL 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 44 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 left front brake fluid pressure voltage (VPRFL) with the HDS.
Is there about 0.5 V?

YES - Go to step 6.

NO - Go to step 9.
Test the brake booster (see BRAKE BOOSTER TEST ).
Press the brake pedal with about 314 N (32 kgf, 70.6 lbf) pressure.
Check the left front brake fluid pressure voltage (VPRFL) with the HDS.
Is there about 2.5 V?

YES - The left 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 left front pressure sensor.

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

Fig 2: Connecting Left 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 left front pressure sensor.
Remove the jumper wire from the left 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. 14 terminal and body ground.

Fig 5: Checking For Continuity Between ACC Unit 20P Connector No. 14 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 left front pressure sensor.

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

Fig 6: Connecting Left 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. 14 terminal and body ground.

Fig 7: Checking For Continuity Between ACC Unit 20P Connector No. 14 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 left 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 FL line and the 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 left front pressure sensor.
Remove the jumper wire from the left 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. 14 terminals.

Fig 10: Measuring Voltage Between ACC Unit 20P Connector No. 3 And No. 14 Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there about 0.5V?

YES - Go to step 31.

NO - Replace the left 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 44 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.