Code No. B1643 Rear detect sensor communication error
Code No. B1644 Rear detect sensor communication impossible

OPERATION

The rear detect sensor transmits the coded acceleration data to the SRS-ECU. Based on that data, the SRS-ECU then determines if the high voltage shutdown shall be performed, and sends a high voltage shutdown signal to the EV-ECU.

TROUBLE JUDGEMENT

When the communication between the rear detect sensor and SRS-ECU is abnormal, code No. B1643 is set, or when impossible, code No. B1644 is set.

PROBABLE CAUSES

Malfunction of the rear detect sensor
Damaged harness wires and connectors
Malfunction of SRS-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check C-114 wiring harness between the rear detect sensor connector terminal No. 1, 2 and B-113 SRS-ECU connector terminal No. 12, 11.

Check the rear detect sensor output line for open circuit and short circuit.

Q. Is the check result normal?

	Replace the rear detect sensor.(Refer to ) Then proceed to step 2.

	Repair the wiring harness.

STEP 2. Diagnosis code recheck

Q. Is No. B1643 or B1644 set?

	Replace the SRS-ECU.(Refer to .)

	Intermittent malfunction. (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .)

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Code No. B1643 Rear detect sensor communication errorCode No. B1644 Rear detect sensor communication impossible