Code No.U0171 Right front impact sensor communication error
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caution |
If the diagnosis code U0171 is set to SRS-ECU, be sure to diagnose the CAN bus line.
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If an impact of set value or more is detected, the front impact sensor sends the coded acceleration data to SRS-ECU. Based on the acceleration data, SRS-ECU determines the necessity of driver’s and passenger’s (front) air bag, knee air bag and seat belt pre-tensioner deployment, and then turns ON the power supply circuit to the inflator.
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The code is set if the communication between the right front impact sensor and SRS-ECU is abnormal.
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- Malfunction of right front impact sensor
- Damaged wiring harness and connectors
- Malfunction of SRS-ECU
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STEP 1. M.U.T.-III CAN bus diagnostics.
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Use M.U.T.-III to diagnose the CAN bus lines.
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Q.
Is the check result normal?
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Go to Step 2.
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Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ).
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STEP 2. Check whether the diagnosis code is reset.
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(1)Connect the negative battery terminal.
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(2)After erasing the diagnosis code memory, check the diagnosis code again.
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(3)Disconnect the negative battery terminal.
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Q.
Is the diagnosis code No. U0171 set?
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Go to Step 3.
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Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
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STEP 3. Right front impact sensor check.
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(1)Check that the negative battery terminal is disconnected. If the negative battery terminal is connected, disconnect it.
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(2)Alternate the right front impact sensor and left front impact sensor, and then install the alternated sensors.
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(3)Connect the negative battery terminal.
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(4)After erasing the diagnosis code memory, check the diagnosis code again.
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(5)Disconnect the negative battery terminal.
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Q.
Is the diagnosis code No. U0170 set?
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Replace the right front impact sensor (Refer to ).
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Go to Step 4.
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STEP 4. Wiring harness check between the A-46 right front impact sensor connector terminal No. 1/2 and the C-122 SRS-ECU connector terminal No. 24/23.
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note |
Prior to the wiring harness inspection, check the A-37, C-128 intermediate connector, and repair if necessary.
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- Wiring harness check for open and short circuit between right front impact sensor and SRS-ECU
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Q.
Is the check result normal?
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Go to Step 5.
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Repair the wiring harness.
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STEP 5. Check whether the diagnosis code is reset.
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Q.
Is the diagnosis code No. U0171 set?
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Replace SRS-ECU (Refer to ).
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Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
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