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HOMESERVICE MANUALSHONDA2020CIVIC SPORT, 4D HATCHBACK, STANDARD TRANSREPAIR AND DIAGNOSISACCESSORIES & EQUIPMENTDRIVERS ASSISTANCE SYSTEMS - ADASPARKING OR BACK-UP SYSTEM - DIAGNOSTICSDTC TROUBLESHOOTINGDTC B2649

2020 Honda Civic Sport, 4D Hatchback, Standard Trans

DTC B2649

2020 Honda Civic Sport, 4D Hatchback, Standard TransSECTION DTC B2649

DTC B2649 : Rear Sensor Signal Short to Ground

NOTE:

If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A .
The connection order of the sensor is 1st -> 2nd -> 3rd -> 4th from the side near the control unit.

DTC Description	DTC
B2649 Rear Sensor Signal Short to Ground

DTC (Parking and Back-Up Sensor Control Unit)

Problem verification

-1. Clear the DTCs with the HDS.

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

-3. Wait for at least 6 seconds.

-4. Check for DTCs with the HDS.

DTC Description	DTC
B2649 Rear Sensor Signal Short to Ground

Is DTC B2649 indicated?

YES

Go to step 2.

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

Shorted wire check (SOR SIDE L, E2 SIDE L lines) 1

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

-2. Disconnect the following connector.

Parking and back-up sensor control unit 16P connector

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

Test condition	Vehicle OFF (LOCK) mode Parking and back-up sensor control unit 16P connector: disconnected
Test point 1	Parking and back-up sensor control unit 16P connector No. 14
Test point 2	Parking and back-up sensor control unit 16P connector No. 12

Is there 1 MΩ or more?

YES

Go to step 10.

Go to step 3.

Shorted wire check (SOR SIDE R, E2 SIDE R lines) 1

-1. Disconnect the following connector.

Right rear center sensor 6P connector

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

Test condition	Vehicle OFF (LOCK) mode Parking and back-up sensor control unit 16P connector: disconnected Right rear center sensor 6P connector: disconnected
Test point 1	Right rear center sensor 6P connector No. 3
Test point 2	Right rear center sensor 6P connector No. 1

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

Is there 1 MΩ or more?

YES

Go to step 5.

Go to step 4.

Shorted wire check (SOR SIDE R, E2 SIDE R lines) 2

-1. Disconnect the following connector.

Right rear corner sensor 6P connector

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

Test condition	Vehicle OFF (LOCK) mode Parking and back-up sensor control unit 16P connector: disconnected Right rear center sensor 6P connector: disconnected Right rear corner sensor 6P connector: disconnected
Test point 1	Right rear center sensor 6P connector No. 3
Test point 2	Right rear center sensor 6P connector No. 1

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

Is there 1 MΩ or more?

YES

Replace the right rear corner sensor .

Repair a short in the SOR SIDE R and E2 SIDE R wires between the right rear center sensor and the right rear corner sensor.

Shorted wire check (SOR CTR R, E2 CTR R lines) 1

-1. Reconnect the following connector.

Right rear center sensor 6P connector

-2. Disconnect the following connector.

Left rear center sensor 6P connector

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

Test condition	Vehicle OFF (LOCK) mode Parking and back-up sensor control unit 16P connector: disconnected Left rear center sensor 6P connector: disconnected
Test point 1	Left rear center sensor 6P connector No. 3
Test point 2	Left rear center sensor 6P connector No. 1

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

Is there 1 MΩ or more?

YES

Go to step 7.

Go to step 6.

Shorted wire check (SOR CTR R, E2 CTR R lines) 2

-1. Disconnect the following connector.

Right rear center sensor 6P connector

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

Test condition	Vehicle OFF (LOCK) mode Parking and back-up sensor control unit 16P connector: disconnected Left rear center sensor 6P connector: disconnected Right rear center sensor 6P connector: disconnected
Test point 1	Left rear center sensor 6P connector No. 3
Test point 2	Left rear center sensor 6P connector No. 1

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

Is there 1 MΩ or more?

YES

Replace the right rear center sensor .

Repair a short in the SOR CTR R and E2 CTR R wires between the left rear center sensor and the right rear center sensor.

Shorted wire check (SOR CTR L, E2 CTR L lines) 1

-1. Reconnect the following connector.

Left rear center sensor 6P connector

-2. Disconnect the following connector.

Left rear corner sensor 6P connector

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

Test condition	Vehicle OFF (LOCK) mode Parking and back-up sensor control unit 16P connector: disconnected Left rear corner sensor 6P connector: disconnected
Test point 1	Left rear corner sensor 6P connector No. 3
Test point 2	Left rear corner sensor 6P connector No. 1

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

Is there 1 MΩ or more?

YES

Go to step 9.

Go to step 8.

Shorted wire check (SOR CTR L, E2 CTR L lines) 2

-1. Disconnect the following connector.

Left rear center sensor 6P connector

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

Test condition	Vehicle OFF (LOCK) mode Parking and back-up sensor control unit 16P connector: disconnected Left rear corner sensor 6P connector: disconnected Left rear center sensor 6P connector: disconnected
Test point 1	Left rear corner sensor 6P connector No. 3
Test point 2	Left rear corner sensor 6P connector No. 1

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

Is there 1 MΩ or more?

YES

Replace the left rear center sensor .

Repair a short in the SOR CTR L and E2 CTR L wires between the left rear corner sensor and the left rear center sensor.

Shorted wire check (SOR SIDE L, E2 SIDE L lines) 2

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

Test condition	Vehicle OFF (LOCK) mode Parking and back-up sensor control unit 16P connector: disconnected Left rear corner sensor 6P connector: disconnected
Test point 1	Parking and back-up sensor control unit 16P connector No. 14
Test point 2	Parking and back-up sensor control unit 16P connector No. 12

Is there 1 MΩ or more?

YES

Replace the left rear corner sensor .

Repair a short in the SOR SIDE L and E2 SIDE L wires between the parking and back-up sensor control unit and the left rear corner sensor.

Shorted wire check (SOR 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 16P connector: disconnected
Test point 1	Parking and back-up sensor control unit 16P connector No. 14
Test point 2	Body ground

Is there 1 MΩ or more?

YES

Replace the parking and back-up sensor control unit .

Repair a short to ground in the SOR SIDE L wire.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.