[ Model - ECLIPSE CROSS / Year - 2018 ]
2018 / ECLIPSE CROSS / EC - Workshop Manual
52 -INTERIOR AND SUPPLEMENTAL RESTRAINT SYSTEM(SRS) > 52B-SUPPLEMENTAL RESTRAINT SYSTEM (SRS) > TROUBLESHOOTING > DIAGNOSIS CODE PROCEDURES > DTC B1672 SEAT BELT PRE-TENSIONER (LH) SQUIB DRIVE CIRCUIT (GROUND SIDE) SHORT-CIRCUITED
Code No.B1672 Seat belt pre-tensioner (passenger’s side) (squib) system (shorted to squib circuit earth)
 
 
cautionIf the diagnosis code B1672 is set to SRS-ECU, be sure to diagnose the CAN bus line.
 
 
OPERATION
Only when the frontal impact exceeding the threshold is simultaneously detected (turned ON) by the front impact sensor as well as by the analogue G-sensor in SRS-ECU, the electric current is supplied from SRS-ECU to the seat belt pre-tensioner (squib).
 
 
TROUBLE JUDGEMENT
The code is set when the input terminal of SRS-ECU seat belt pre-tensioner (passenger’s side) (squib) is shorted to earth.
 
 
PROBABLE CAUSES
  • Damaged wiring harness and connector
  • Seat belt pre-tensioner (passenger’s side) (squib) harness shorted to earth
  • Malfunction of SRS-ECU
 
 
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-IIISE CAN bus diagnostics.
Use M.U.T.-IIISE to diagnose the CAN bus lines.
Is the check result normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ).
 
STEP 2. Check whether the diagnosis code is set again.
(1) Connect the negative battery terminal.
(2) After erasing the diagnosis code memory, check the diagnosis code again.
(3) Disconnect the negative battery terminal.
Is the diagnosis code No. B1672 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 seat belt pre-tensioner (passenger's side) harness side connector.
 
(3) Connect special tool dummy resistor (MB991865) to special tool resistor harness (MB991884).
(4) Connect special tool resistor harness to the seat belt pre-tensioner (passenger's side) harness side connector.
(5) Connect the negative battery terminal.
(6) After erasing the diagnosis code memory, check the diagnosis code again.
(7) Disconnect the negative battery terminal.
Is the diagnosis code No. B1672 set?
Go to Step 4.
Replace the seat belt with pre-tensioner (passenger’s side) (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)
dangerTo release the SRS-ECU connector short spring in the following operations, disconnect this seat belt pre-tensioner 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 seat belt pre-tensioner (passenger's side) harness side connector.
 
(4)
cautionThe short spring may not be released due to the insufficient insertion. Therefore, insert the insulator for 4 mm or more.
Insert an insulator (width: 3 mm, thickness: 0.5 mm) such as cable tie between the PTA+, PTA- line, and the short spring, and release the short spring.
(5) Take the measurements below at the SRS-ECU harness side connector.
  • Continuity between PTA+, PTA- line and body earth
OK: No continuity
Is the check result normal?
Go to Step 5.
Repair the wiring harness PTA+, PTA- line between the SRS-ECU connector and the seat belt pre-tensioner (passenger's side) connector.
 
STEP 5. Check whether the diagnosis code is set again.
Is the diagnosis code No. B1672 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 ).