DTC B2638-87 (2021)

DTC B2638-87  : Lost Communication With The Front Left Corner Sensor

NOTE:  If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A .

DTC (Parking and Back-Up Sensor Control Unit)

1. Problem verification

   -1. Clear the DTCs with the HDS.

   -2. Turn the vehicle to the OFF (LOCK) mode and then the ON mode.

   -3. Turn the parking and back-up sensor switch to ON.

   -4. Wait for at least 6 seconds.

   -5. Check for DTCs with the HDS.

   DTC Description	DTC
   B2638-87 Lost Communication With The Front Left Corner Sensor

   Is DTC B2638-87 indicated?

   YES 

   Go to step 2.

   YES 

   Go to step 3.

   NO 

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

2. DTC check

   -1. Check for DTCs with the HDS.

   DTC Description	DTC
   B2638-87 Lost Communication With The Front Left Corner Sensor
   B2641-87 Lost Communication With The Front Right Corner Sensor

   Are DTC B2638-87 and B2641-87 indicated?

   YES 

   Go to step 7.

   NO 

   Go to step 4.

   NO 

   Check for loose or poor connections. If OK, replace the parking and back-up sensor control unit .

3. DTC check

   -1. Check for DTCs with the HDS.

   DTC Description	DTC
   B2638-87 Lost Communication With The Front Left Corner Sensor
   B2639-87 Lost Communication With The Front Left Center Sensor
   B2640-87 Lost Communication With The Front Right Center Sensor
   B2641-87 Lost Communication With The Front Right Corner Sensor

   Are DTC B2638-87, B2639-87, B2640-87, and B2641-87 indicated?

   YES 

   Go to step 7.

   NO 

   Go to step 4.

   NO 

   Check for loose or poor connections. If OK, replace the parking and back-up sensor control unit .

4. Left front corner sensor check

   -1. Substitute a known-good left front corner sensor .

   -2. Clear the DTCs with the HDS.

   -3. Turn the vehicle to the OFF (LOCK) mode and then the ON mode.

   -4. Turn the parking and back-up sensor switch to ON.

   -5. Wait for at least 6 seconds.

   -6. Check for DTCs with the HDS.

   DTC Description	DTC
   B2638-87 Lost Communication With The Front Left Corner Sensor

   Is DTC B2638-87 indicated?

   YES 

   Go to step 5.

   NO 

   Replace the original left front corner sensor .

5. Shorted wire check (SOF SIDE L line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the following connector.

   Left front corner sensor 3P connector

   Parking and back-up sensor control unit 24P connector

   -3. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode Left front corner sensor 3P connector: disconnected Parking and back-up sensor control unit 24P connector: disconnected
   Test point 1	Left front corner sensor 3P connector (female terminals) No. 2:
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   Repair a short to ground in SOF SIDE L wire between the left front corner sensor and the parking and back-up sensor control unit.

   NO 

   The SOF SIDE L wire is not shorted to ground, go to step 6.

6. Open wire check (SOF SIDE L line)

   -1. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode Parking and back-up sensor control unit 24P connector: disconnected Left front corner sensor 3P connector: disconnected
   Test point 1	Parking and back-up sensor control unit 24P connector No. 6
   Test point 2	Left front corner sensor 3P connector (female terminals) No. 2:

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The SOF SIDE L wire is not opened, go to step 7.

   NO 

   Repair an open or high resistance in SOF SIDE L wire between the parking and back-up sensor control unit and the left front corner sensor.

7. Open wire check (BOF SIDE L, E1 SIDE L lines)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the following connectors.

   Parking and back-up sensor control unit 24P connector

   Left front corner sensor 3P connector

   -3. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode Parking and back-up sensor control unit 24P connector: disconnected Left front corner sensor 3P connector: disconnected
   Test point 1	Parking and back-up sensor control unit 24P connector No. 2
   Test point 2	Left front corner sensor 3P connector (female terminals) No. 3:

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   Repair an open or high resistance in E1 SIDE L wire between the parking and back-up sensor control unit and the left front corner sensor.

   NO 

   Repair an open or high resistance in BOF SIDE L wire between the parking and back-up sensor control unit and the left front corner sensor.