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DTC B1627 Lap pre-tensioner (RH) (squib) system (shorted to squib circuit ground)
 
 
cautionIf DTC B1627 is set in SRS-ECU, be sure to diagnose the CAN bus line.
 
 
OPERATION
Only when the frontal collision impact that exceeds the threshold is simultaneously detected (turned ON) by the front impact sensor as well as by the analog G-sensor and safing G-sensor in SRS-ECU, the electric current is supplied from SRS-ECU to the lap pre-tensioner (RH) (squib).
 
 
 
TROUBLE JUDGMENT
The code is set when the input terminal of SRS-ECU driver's lap pre-tensioner (RH) (squib) is shorted to ground.
 
 
 
PROBABLE CAUSES
  • Poor contact of connector
  • Passenger's lap pre-tensioner (RH) (squib) harness shorted to ground
  • Malfunction of SRS-ECU
 
 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-IIISE), diagnose the CAN bus line.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-IIISE).
Connect scan tool (M.U.T.-IIISE). Refer to "How to connect the scan tool ."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the CAN bus line found to be normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C, Diagnosis ).
 
STEP 2. Using scan tool (M.U.T.-IIISE), check whether the DTC is set again.
(1) Connect the negative battery terminal.
(2) After erasing the DTC memory, check the DTC again.
(3) Disconnect the negative battery terminal.
Is DTC B1627 set?
Go to Step 3.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
 
STEP 3. Diagnosis check by dummy resistor connection.
(1) Check that the negative battery terminal is disconnected. If the negative battery terminal is connected, disconnect it.
(2) Use the flat-tipped screwdriver to pull out the locking button of harness side connector. After releasing the lock, disconnect the lap pre-tensioner (RH) harness side connector.
(3) Connect special tool dummy resistor (MB991865) to special tool resistor harness (MB991884).
(4) Connect resistor harness to the lap pre-tensioner (RH) harness side connector.
(5) Connect the negative battery terminal.
(6) After erasing the DTC memory, check the DTC again.
(7) Disconnect the negative battery terminal.
Is DTC B1627 set?
Go to Step 4.
Replace the seat belt with pre-tensioner (RH) (Refer to ).
 
STEP 4. Resistance measurement at the SRS-ECU connector.
(1) Check that the negative battery terminal is disconnected. If the negative battery terminal is connected, disconnect it.
(2) Disconnect the SRS-ECU connector.
(3)
dangerDisconnect this lap pre-tensioner (RH) connector, and keep the squib circuit shorted.
Use the flat-tipped screwdriver to pull out the locking button of harness side connector. After releasing the lock, disconnect the lap pre-tensioner (RH) harness side connector.
(4) Take the measurements below at the SRS-ECU harness side connector.
  • Continuity between PA2-, PA2+ line and body ground
OK: No continuity
Is the check result normal?
Go to Step 5.
Repair the wiring harness PA2-, PA2+ line between the SRS-ECU connector and the lap pre-tensioner (RH) connector.
 
STEP 5. Using scan tool (M.U.T.-IIISE), check whether the DTC is set again.
Is DTC B1627 set?
Replace SRS-ECU (Refer to ).
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).